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Troubleshooting

  • Overview
  • Questionnaire Builder
  • I Can't Commit Questionnaires
  • Questionnaires - Worked Examples
  • How do I change the font size/style/colour in the questionnaire?
  • Task Builder - General
  • I Can't Edit a Task
  • One of my Task Displays is not Appearing
  • My Screen is Stuck
  • I'm not Seeing what I Expect when I Preview my Task
  • Task Builder - Spreadsheets
  • I Can't Upload a Spreadsheet
  • My Spreadsheet Columns are Missing
  • My Metadata Columns Are Missing
  • My Task Spreadsheet Contains Extra Columns I Can't Remove
  • Task Builder - Stimuli/Media
  • My Stimuli Won't Display!
  • My Video Stops Partway through an Experiment or Preview
  • My Audio Doesn't Play for Some Participants
  • Media Error Messages
  • Task Builder - Worked Examples
  • How Do I Use Spreadsheets?
  • How Do I Change the Font Size/Style/Colour Of My Text?
  • How Can I Add a Back Button to a Task?
  • How to Allow Participants to Repeat Trials?
  • Experiment Builder
  • It Doesn't Work when I Preview my Experiment
  • Some of my Participants are Still Live
  • My Experiment is Full
  • Experiments - Worked Examples
  • Experiment Not Working As Expected!
  • Data From Some Of My Participants Is Missing!
  • Embedded Data Troubleshooting
  • My Branching Isn't Working
  • Embedded Data Don't Display Correctly
  • The Embedded Data I'm Trying to Save is Too Large
  • Metrics Troubleshooting
  • My Metrics Look Wrong
  • I See Strange Characters in my Spreadsheet
  • All my Metrics are in One Column
  • My Metrics Appear 'Out of Order'
  • Numbers in my Data Don't Make Sense
  • Participants' Reaction Times Look Odd
  • Duplicate Metrics
  • Repeated Trials
  • Missing Metrics
  • My Data Still Haven't Generated
  • Scripting Troubleshooting
  • My Code Won't Run/Doesn't Work
  • Advanced Features & Technical Troubleshooting
  • The Message 'Please Switch to Landscape Mode' Won't Go Away
  • Beta and Closed Beta Zones
  • Other Issues

Welcome to Troubleshooting


Explore the list of questions in the menu to the left. Here you can troubleshoot solutions to commonly asked questions.

If you have general questions about using Gorilla try these How To Guides:

I Can't Commit Questionnaires


This is often because two nodes (questionnaire widgets) have the same key. If this is the case, an error message, like the one below, will be displayed.

Error Message
'Two of your nodes have the same key:  response-2'

Each widget in the questionnaire has to have a unique key. You can leave them as they are when you add the widget (response-1, response-2, response-n), or you can rename them to be more meaningful.

How do I change the font size/style/colour in the questionnaire?


You can change the font size, style and colour of your text using HTML applied to each word/phrase.

In the example below, I have changed the colour and enlarged the Demographics heading, as well as changed the font style of the instructions using the HTML formatting.

questionnaire html formatting

I Can't Edit a Task


There are generally three reasons why you might not be able to edit a task:

  1. You haven't pressed the Edit button
  2. Someone else is has an open change on the same task (someone else is editing the task)
  3. You don't have edit rights (often the case in your Library or the Samples folder)

Details of what to do in each case:

  1. Once you have gone into a task, if you want to edit it, the first thing to do is press the red EDIT button near the top right below the red PREVIEW button
  2. If someone else has an open change, when you click EDIT, a modal dialogue will come up saying that you can't edit the task because someone else is. They will need to commit (or discard) their change, and then you will be able to EDIT the task.
  3. To make sure you have edit rights click on setting>collaborate near the top right of the page. Only someone with Admin rights can change the permissions.
  4. If you don't have edit right, you can always Clone the task to create your own editable copy. Create New Task > From Existing > Select the task

One of my Task Displays is not Appearing


I've set up my display, but when I preview my task, this display is being skipped over and isn't shown.

There are two common causes for this issue:

  1. You have set up the Display in the Task Structure, but you haven't entered the display name correctly into the spreadsheet.
  2. Your Display name contains spaces, special characters or punctuation.
  3. Tried the above but Display still not showing?

Here's what to do in each case:

1. You have set up the Display in the Task Structure, but you haven't entered the display name correctly into the spreadsheet.

Solution:

1) Download the spreadsheet you are running your Task from. 2) Highlight and Copy the name of the Display you are having problems with. 3) Paste the name into the 'Display' Column of your spreadsheet & double check there are no trailing spaces at either end. 4) Save your amended spreadsheet and upload it to Gorilla.


2. Your Display name contains spaces, special characters or punctuation.

Display names are Casesensitive. Thus, the most common reason for a Display not appearing is 'stray spaces'.

Its very easy to accidentally put an extra space into your Display names (or when entering these names into the spreadsheet). Most commonly this occurs at the beginning or end of the name when entering the display into the spreadsheet.

Solution:

1) Remove all spaces from your Task's Display names. Instead use camelCase or PascalCase as the format of your display names. 2) Remove all special characters & Punctuation from your Task's Display names. 3) Download your existing spreadsheet and replace your old display names with your new ones. 4) Save your amended spreadsheet and upload it to Gorilla.


3. My Display still isn't showing?

I've removed all spaces & special characters from my display names and reuploaded a new spreadsheet but it's still not showing this Display.

Get in contact with us via our Support Contact Form. Provide us with a link to your task and we will happily take a look at your issue directly.


My Screen is Stuck


See the video below to learn 3 ways to get your task moving forward when it appears to be 'stuck' on a screen.

FAQ Task Builder

Length (mins): 5:47

I'm not Seeing what I Expect when I Preview my Task


There are three common reasons why your task preview may be different from what you expected:

  1. I get a blank screen on previewing my Task/ part-way through previewing my Task

    1. You have included a 'blank' or 'empty' Screen in one of the Displays of your task.
    2. Identify where the blank screens are in your displays.
    3. Either; (1) Delete the blank screens. (2) Add a 'Timelimit' (Screen) Zone to the blank screen (If you wish to keep the blank screen); this way gorilla will know to move on from this screen automatically. (3) Add a 'Fixation' or 'Continue Button' Zone to your blank screen; this way a participant can move on from this screen.
  2. I get a blank screen and the error message 'No source for the media could be found! Try refreshing the page. If the problem persists, contact the researcher for the experiment'.

    1. A Stimulus is missing or misnamed.
    2. First check the Stimuli tab and double check that All your stimuli are uploaded? If you have any doubts or cannot find a stimuli upload your stimuli again and re-preview your task.
    3. Go through the Stimuli file names in your Zones (or your Spreadsheet). Check that the file name is correct, with no spelling errors, nor spaces before or after the file name. Make sure you have included the full file name (including the .mp3/.png/.jpg ect.). Correct any mistakes in the file names where they appear.
  3. When I preview my Task it doesn't look how I am expecting it to (but my displays are working as I expect them to).

    1. Your Spreadsheet is incorrect.
    • First check the spreadsheet tab: Select the spreadsheet you are trying to preview from the 'Show spreadsheet' drop-down menu. Does this look correct?
      • If in doubt; Press the Edit button. Make sure the correct spreadsheet is selected under 'Show spreadsheet' drop down menu. Press 'Upload Spreadsheet' button. Upload the correct spreadsheet.
    1. You are using Manipulations and haven't selected the correct Spreadsheet.
    • When previewing an experiment, be sure to select the correct spreadsheet before pressing the 'Launch' button.

I Can't Upload a Spreadsheet


There are three common reasons why you might not be able to upload a spreadsheet:

  1. You have not pressed the Edit button. You can only upload spreadsheets to a task while you are in Edit mode.
  2. Try uploading the spreadsheet in a different file format (XLSX, CSV or ODS).
  3. The file is corrupted. If this is the case trying opening the original spreadsheet in your preferred package and try again.

I Uploaded a Task Spreadsheet but some Columns are Missing


There are two different causes for spreadsheet columns appearing to be missing. Both of which typically occur on your Task's spreadsheet page after a new spreadsheet has been uploaded.

Note: This issue usually only arises when using multiple spreadsheets within your task.

To debug this issue first identify what 'type' of spreadsheet column has gone missing:

  1. Spreadsheet Metadata Column: You are using Metadata columns but have not included the metadata column in all spreadsheets.
  2. Spreadsheet Source Column: You are using the spreadsheet to control the task content.

Here's what to do in each case:

1. Spreadsheet Metadata Column is missing:

Please refer to this dedicated troubleshooting page: Metadata column is missing.

2. Spreadsheet Source Column is missing:

You uploaded a new spreadsheet to your task and one or more of the columns associated with controlling your spreadsheet does not appear.

Explanation: Gorilla helpfully removes columns which it detects as not in use: This includes empty columns not referenced within the task structure (i.e. columns not linked to a specific zone via setting the source to spreadsheet).

This helps keep both the task spreadsheet and the subsequent metrics produced from the task as clean as possible.

Common Causes:

1) The spreadsheet being uploaded did not contain all the columns. 2) The spreadsheet column is not linked to any zone in your Task Structure. 3) The spreadsheet column is used within your task but it's source is set to Spreadsheet-manipulation.

Solutions:

Case 1

  1. Reopen your spreadsheet locally using your preferred software (e.g. Excel) and check that the required columns are present and formatted correctly.
  2. Resave your spreadsheet in a recommended file format: XLSX, ODS and CSV formats.
  3. Reupload your newly saved spreadsheet to your task.

Case 2

  1. Often this is caused by a simple typo. Names in Gorilla are Cases-sensitive. Column heading names and Labels used in the task zones must match exactly.
  2. Doublecheck the name used in your task exactly matches the one in your spreadsheet. Reupload your corrected spreadsheet.
  3. Doublecheck the source is set to 'Spreadsheet' for your zone.

Case 3

  1. Columns set to spreadsheet manipulation are not directly linked to your spreadsheet by the name given. Therefore such columns will be recognised by Gorilla as Metadata columns.

Please refer to this dedicated troubleshooting page: Metadata column is missing for help with this issue.


I Uploaded A Task Spreadsheet, But My Metadata Columns Are Missing


There are two different causes for metadata columns appearing to be missing. Both of which typically occur on your Task's spreadsheet page after a new spreadsheet has been uploaded.

Common Causes:

1) The spreadsheet being uploaded did not contain all the columns. 2) The uploaded metadata column is empty and is not present in all of the spreadsheets uploaded to the task.

Explanation: Gorilla helpfully removes all columns which it detects as not in use. This includes empty columns and those not referenced within the task structure. Where an 'empty column' means there are no data entries in any row beneath the column heading.

This helps keep both the task spreadsheet and the subsequent metrics produced from the task as clean as possible.

Solutions:

Case 1

  1. Reopen your spreadsheet locally using your preferred software (e.g. Excel) and check that the required columns are present and formatted correctly.
  2. Resave your spreadsheet in a recommended file format: XLSX, ODS and CSV formats.
  3. Reupload your newly saved spreadsheet to your task.

Case 2

Metadata columns with data inside will be visible so long as there is at least one spreadsheet - within all the spreadsheets uploaded to the task - which contains at least one row of data.

Usually this is not problematic but there are instances where empty metadata columns are required. You can read more about this and using Metadata Columns Spreadsheet Walkthrough here.

Recommended Solution:

  1. Make sure to include your empty metadata columns on all spreadsheets you upload to your task. Even if an individual spreadsheet does not itself, use the metadata column.

Other solutions:

  1. Add an additional 'dummy' spreadsheet to your task which is used to save all your metadata columns. The 'dummy' spreadsheet must include all your metadata columns, each with at least one row of data filled in below each heading.

As spreadsheet columns are visible to all spreadsheets - regardless of whether they are in use by an individual particular spreadsheet or not. These metadata columns will now always appear in each of your spreadsheet without disappearing if they are empty. This is particularly useful when working with spreadsheet-manipulations and/or scripts.


My Task Spreadsheet Contains Extra Columns I Can't Remove


'I've uploaded a new spreadsheet to my Task but extra columns are being displayed on my Spreadsheet Tab page and I can't get rid of them!'

Sometimes you may notice additional spreadsheet columns in your spreadsheet and/or metrics. Generally these are not problematic to the running of the task and can be either safely ignored or removed.

There are three common causes for extra spreadsheet columns appearing:

Common Causes:

1) These 'extra' columns are being used by another spreadsheet within your task. 2) The 'extra' column is linked somewhere within your task structure. 3) For some zones, if a zone is set to spreadsheet and changed to another zone type which no longer requires the setting the column may remain in your spreadsheet, even if no longer in use.

Solutions:

Case 1

Regardless of whether a particular column is in use by an individual spreadsheet. Non empty columns which belong to any spreadsheet uploaded to a task, will appear in all spreadsheets for that task.

For example: If spreadsheet-1, contains columns 'A' and 'B' and spreadsheet-2 contains columns 'C' and 'D'. So long as there is at least one row of data under each column heading: All columns, 'A', 'B', 'C' and 'D' will appear in both spreadsheet-1 and spreadsheet-2.

If you wish to remove a column:

  1. Systematically remove the column (heading and contents) from all spreadsheets within your task.
  2. Remove all references to the column from Zones within your Task Structure.
  3. Reupload all spreadsheets.

The column should now be removed.

Case 2

If a spreadsheet column is referenced in your task structure but is not included in your uploaded spreadsheet the column name will appear as a, green headed, empty column on your Task Spreadsheet page.

If you wish to remove this column:

  1. Often this is caused by a simple typo. Names in Gorilla are Cases-sensitive. Column heading names and Labels used in the task zones must match exactly. Beware of trailing spaces.
  2. Doublecheck the name used in your task exactly matches the one in your spreadsheet. Reupload your corrected spreadsheet.
  3. Doublecheck that your task structure does not contain any references to this column heading, and that if it does, that this Zone's source is not set to 'Spreadsheet'.

Alternatively - if you intended to use this column but it has been misnamed: Rename the Zone Content so that it exactly matches the spreadsheet column heading you wish to use instead

  1. On your Tasks Spreadsheet page: Locate the spreadsheet column name which should be linked to your Task Zone.
  2. Copy the name exactly.
  3. Locate the Zone in your Task Strucure, that should be linked with your spreadsheet.
  4. Paste the name into the Zone.
  5. Doublecheck that the Zone's source is set to spreadsheet.

Case 3

You can safely ignore this spreadsheet column and remove any references to this column from your metrics. It will not affect the running of your task.

If you wish to remove this column:

  1. Restore the original Zone type.
  2. Delete the Zone: In Edit mode, Click 'Edit Layout', locate the zone and click the 'remove' button.

The column should now be removed.


My Stimuli Won't Display!


If you are previewing your experiment and notice that some of the stimuli you expected to see are not displaying, try the following steps:

  1. In your Stimuli Tab double check that you have uploaded all the stimuli that you need for your experiment.
  2. Go through the Stimuli file names in your Zones and your Spreadsheet. Check that the file name is correct, with no spelling errors, nor spaces before or after the file name. Make sure you have included the full file name (including the .mp3/.png/.jpg ect.). Correct any mistakes in the file names where they appear.
  3. In your Spreadsheet Tab check whether all stimuli are recognised - i.e. whether the column heading where your stimuli are displayed at appears as green as opposed to faded/white.
  4. Check that you are using the supported stimuli type. Read more on which stimuli type are supported in our How To: Task Builder guide.

My Video Stops Partway through an Experiment or Preview


If your video stops playing part way through, this is typically because your video file is corrupted in some way.

On Chrome, an error message will appear when this occurs, and video play error information will appear in your metrics. This means that if you launch an experiment containing a corrupted video, only participants on Chrome will show any error in the data.

In this case, you need to use a different video file.

My Audio Doesn't Play for Some Participants


Is your audio set to play automatically instead of on a click or key press?

If so, this problem is likely caused by Autoplay issues. See our guide here.

If your audio is set to manual play, please contact us via our support form and include information about the device and browser this problem occured on.

Media Error Messages


For a full guide to Media Error Messages check out our dedicated Help Page: Troubleshooting: Media Error Messages


There are three places where you may encounter a 'Media Error Message'.

1) On your Task Stimuli page when uploading an image, audio or video stimuli. 2) When previewing your Task either in Task preview or Experiment Preview. 3) As feedback from a participant who has taken part in your Live experiment.

Explanation:

Gorilla's Media Error messages have been added to help you create a task which will work consitently and robustly across all browsers and devices.

Media Error messages will be triggered if Gorilla notices that there is something wrong with your stimuli which could result in your task performing sub-optimally or, in the worst case, prevent your task from working at all.

Solution:

1) The most common Media Error message which occurs will be informing you that the stimuli you have just uploaded is not in a supported format.

When you preview your Task you may find that your task and stimuli seem to work just fine. However, depending upon the stimuli type you may find that performance will differ between different browsers and different devices.

To avoid any risk and disapointment that your task will not display correctly for some participants we highly recommend you convert your stimuli to one of the supported web-compatible file types.

If you are sure of which file types are supported you can find out here: Supported File Types. Alternatively, you can find out which file types are supported on a particular Zone by reviewing the Zone's dedicated Tooling Reference Guide page.

2) The most common Media Error message which occurs when previewing a Task is that the media cannot be found.

  • First, Identify the name of the stimuli that is missing and check that you have Uploaded the stimuli on your Stimuli page.
  • Check that the name of your stimuli in your Task Zone or Spreadsheet is identical (case sensitive) to that found on your stimuli page.
  • Check that there are no extra spaces or line breaks around your stimuli name within your task or spreadsheet. White space is counted within your task names and will count as a mismatch if it is not identical.

If these steps do not fix your error please refer to our dedicated Media Error Messages help page.

3) As feedback from a participant who has taken part in your Live experiment.

  • Check your metrics for this participant: Any media error messages that occured while the participant was undertaking your task will be written into your metrics.

Use our dedicated Media Error Messages help page to identify the message you received and find the appropriate solution.

The majority of reports from participants about Media Error messages can be avoided by previewing your task and experiment fully before releasing your experiment Live.

Once this is successful a small pilot across all browsers you intend to use during your experiment is very highly recommended.

Piloting your full study across all browsers and devices you intend to use will usually pick up any additional media errors which may occur and allow you to prevent them from reoccuring when you come to launch your full experiment.

What is spreadsheet? Why do I need it? How do I set it up correctly?


The spreadsheet is the basis for the task in Gorilla, it drives the task telling Gorilla what should be displayed and in what order. This means that you have to upload a spreadsheet for a task to work on Gorilla, even for the simplest task.

Spreadsheet is a simple table where you put information about one trial per one row.

In Gorilla Task Builder, you create displays (e.g. 'instructions', 'trial' and 'goodbye' diplays) that contain screens with specific zones.

You do not need to manually set up each of the trials on separate screen within the Task Structure Tab - you simply list all your trials within the spreadsheet that Gorilla will read and follow when displaying your task.

Worked example:

The example below discusses the Trial Randomisation Math Test example.

If you have 5 maths questions that you want to display to participants on 5 screens and ask them to solve them, instead of creating 5 separate screens and typing your math equations on each of them, you could only use one math equation screen within 'test' display and in your Rich Text Zone specify that you want the equations to be read from the spreadsheet column source called MathsQuestions. This way Gorilla will read from the specified spreadsheet column what images should be displayed on the screens and run as many trials as you specify in your spreadsheet!

For example, in case where you have 5 trials you would need to have 5 rows in your display column called test and 5 rows with maths equations in your MathsQuestions column. See an examplar Task and Spreadsheet set-up below!

I only have two screens in my 'test' display: Screen 1 with a fixation cross and Screen 2 with my math equation typed in the Rich Text Zone with a zone source specified as a MathsQuestions spreadsheet column.

task structure setup

Because I chose spreadsheet as my zone source, Gorilla now decides what will be displayed in Screen 2 from the spreadsheet I uploaded in the Spreadsheet Tab. In this case, it will run all 5 maths quations from the MathsQuestions column in my test display. See the spreadsheet set-up on the image below:

spreadsheet setup example

Using Spreadsheets to run your tasks also gives you lots of flexibility when it comes to randomising your trials, block of trials, storing correct responses etc. In the example above, my 5 math equations will be shown in a random order because I have indicated in the randomise_trials column that I want them to be randomised. Read more about randomisation in spreadsheets here.

I have also typed in correct responses into my Answer column. I can later use this as an embedded data to e.g. show participants how many of these equations they have solved correctly. Read more about embedded data here!


Further Resources

For more information on how the spreadsheets work, read our Getting Started Guide and follow our step-by-step Spreadsheet Walkthrough guide for more practical examples!


How do I change the font size/style/colour of my text?


Firstly, you should make sure that the text you are editing is typed in the Rich Text Zone as opposed to using the Text Zone. The Text Zone is meant for displaying simple unfortmatted text (e.g. single words/phrases/short texts) and, unlike the Rich Text Zone, it cannot be styled using Markdown and HTML formatting styles.

The easiest way to change the font size, style and/or colour of your text is to use HTML formatting applied to each stimuli word/phrase.

If in your task you specify the stimuli through Spreadsheet, you would apply HTML formatting to all the words/phrases within the Spreadsheet and Gorilla will read it from there!


Worked example:

Perpahs you would like to display your math equations in different fonts, sizes and colours. You are sourcing your trials from a spreadsheet column called MathsQuestions. In order to format the text in this column you would need to download your spreadsheet and apply HTML formatting, according to this guide. See an examplar spreadsheet below:

spreadsheet text formatting

Then, after saving your edited spreadsheet, you would upload it to your task and gorilla will automatically display the formatted text in your Spreadsheet Tab (see below):

spreadsheet text formatting taskBuilder

Bear in mind that you can combine these and have for example bigger text in a desired font and colour simply by making the HTML line a bit longer in your spreadsheet cell!

If you were using a static source for your Rich Text zone, you would need to apply the HTML formatting around the text that you type in the zone.


Adding Script

Alternatively, you can format your text by adding this script to your task, and adapting it to change the font style and size using the HTML guide. See our Task Builder Scripting guide or watch our instructional video on how to add a custom script to your task!


How Can I Add a Back Button to a Task?


In some cases you might want to allow participants to go back from the current screen they are on to the previous one, for example to give them a chance to review the instructions, see the stimuli again or even change their answer. There is no built-in back button because tasks are designed to progress forwards, not backwards, however, if you want to add this functionality, it can be done and does not require scripting!

Since it's the spreadsheet that runs the task (see this page for more information on Spreadsheets), we can allow participants to go back to the previous screen by jumping back a row in the spreadsheet. To do that, we would use the Jump to Row zone. The Jump to Row zone needs to be combined with within task branching to avoid an infinite loop - pressing a 'back' button sends the participant to a specific screen, containing the Jump to Row zone. Participants who don't press the button will skip the Jump to Row screen. You can learn more about the within task branching from this video.


Worked Example:

Have a look at this Jump to Row zone tutorial: https://app.gorilla.sc/admin/task/28834/editor. In the Task Structure tab, have a look at the screens setup in the display called 'Task'. The Jump to Row zone is positioned on Screen 5. In the screen settings, we indicate that we want participants to jump to the 2nd row in the Spreadsheet when this screen is complete. In the Spreadsheet tab, you will see that row 2 includes the 'TaskInstructions' display. Participants will be automatically directed to the 'TaskInstructions' display after the time limit on jump to row screen (Screen 5 in the 'Task' display) expires.

Now, you would want to direct participants to 'TaskInstructions' display only when they wish to 'go back'. Those who don't, need to be able to skip this. Therefore, we need to create a screen that participants will be directed to in case they do not wish to 'go back' and want to move on. The trick is to use the within task branching settings available for the Active Response zone setting - read more about them in our Tooling Reference Guide.

Have a look at Screen 4 in the 'Task' display. There are two buttons there that participants will click in order to respond. For the purpose of branching, we are setting one of them as a 'correct' and one as an 'incorrect' answer. This is to tell Gorilla which screen should follow when participants choose one button or another. See the images below:

back button2 back button1

In this case, 'Right' has been indicated as a correct answer. When participant clicks the Right button, they will go to Screen 6 and omit the Jump to Row screen, therefore continue without 'going back' in the task. If they click the Left button, however, they will be directed to Screen 5 i.e. the Jump to Row screen (Screen 5) that will take them back to the 'TaskInstructions' display.

Preview the tutorial task, read the instructions on the screens for more details and try out the 'back button' action in practice!


How to Allow Participants to Repeat Trials?


In some cases you might want to allow participants to repeat trials of your task to e.g. read the instructions one more time, see the stimuli again or practice more before they move onto the next part of your experiment.

Since it's the spreadsheet that runs the task (see this page for more information on Spreadsheets), we can allow participants to repeat the trials by jumping back to the previous row in the spreadsheet. To do that, we would use the Jump to Row zone. The Jump to Row zone needs to be combined with within task branching to avoid an infinite loop - pressing a 'back' button sends the participant to a specific screen, containing the Jump to Row zone. Participants who don't press the button will skip the Jump to Row screen. You can learn more about the within task branching from this video.


Worked Example

Have a look at this Jump to Row zone example.

After reading instructions and going through PracticeTrial, participants see the Jump display.

On the first JumpQuestion screen, participants are asked whether they would like to go through the practice trials again or to start a main task. Depending on their responses they will be directed to different screens.

Gorilla branches participants to different screens based on correct, incorrect or timeout answers. When there is no 'correct'/'incorrect' answer, like in this JumpQuestion screen, we can set up one of the answers as 'correct' and one as 'incorrect' just for the purpose of branching. Here we say:

jump to row try again3

Because we can determine one correct answer, only the 'Start Main Task' button will be scored as 'correct'. Any other answer will be scored as 'incorrect' - in our case the 'incorrect' answer will be the other answer we have which is the 'Try Again' button.

Then, in the Branching Settings of the Active Response zone we say 'If correct, advance to screen Continue'. Because we said the 'Start Main Task' button is the 'correct' answer, those participants who choose that button will go to the 'Continue' screen and continue with the task.

We have also set up 'If incorrect, advance to screen TryAgain'. Those participants who click 'Try Again button' (i.e. an answer scored as incorrect) will be directed to the 'TryAgain' screen. See below:

jump to row try again

Now, in the Jump display, TryAgain screen, we place the Jump to row zone. In the zone settings, we say which spreadsheet row the task should jump into when the screen is complete. To complete (i.e. move), the screen, we need to add Timelimit zone and set the time after which the screen will automatically progress. In this example, the screen will jump to row 2 of the spreadsheet after the Timelimit of 5ms expires. See below:

jump to row try again1

As you will see in the Spreadsheet tab, row 2 of the spreadsheet is a row where Gorilla shows the PracticeTrial display. Therefore, when Gorilla jumps to that row, participants will be directed to the practice display again and this way they will repeat the trials!

jump to row try again2

It Doesn't Work When I Preview my Experiment (but Each Element Works Fine)


There are two common reasons you might not be able to preview an experiment:

  1. You haven't connected the nodes together properly. To check, pick each node up and check the arrows are connected.
  2. One of the nodes has never been committed. If this is the case, there is usually a V999... or V0 version of the node in the tree. Open the original element, commit it, and then update it in the tree.

Some of my Participants are Still Live


As soon as a participant starts an experiment (clicks on the recruitment link or is sent a recruitment email) they are marked as 'Live'. They will remain 'Live' until they reach a finish node, at which point they are marked as 'Completed'. It is also at this point that they are automatically 'included' and their metrics become available in your data. For Pay-per-Participant users, this is also the point where a participant token will be consumed.

When a participant is Live, and has only recently joined the experiment, its reasonable to assume that they are still taking part and just need a little more time to finish. If a participant has been Live for a very long time the most likely scenario is that, unfortunately, they have chosen to leave the experiment. This could have happened very early on: perhaps they chose not to consent. Or, very late in the experiment: they may have gotten interrupted by something else and had to leave the experiment.

To help you work out where a participant is in an experiment, its really helpful to include Checkpoint Nodes.

These are available in the experiment tree and we recommend putting then in between key components of your task. The most recent Checkpoint node that a participant passed through is recorded in the Participant tab of your experiment. This way you can work out how far through your experiment a Live participant is and how likely it is that they are still working on your experiment, or have simply left. For Pay-per-Participant users, this is allows you to make an informed choice on whether or not to include a live participants data, consuming a token, or reject them and have the token returned. You can then choose to include only those participants who have progressed far enough through your experiment that their data is worthwhile including.


Read more on participant status, how to include and reject them when needed from our How To: Participants guide!

My Experiment is 'Full'


If your participants are being turned away with the message that the Experiment is full, there are two possibilities:

  1. You have not set a Recruitment Target. For more information on setting a Recruitment Target, see the How To: Experiments guide.
  2. Your Recruitment Status is 'Full'.

If your Experiment is ‘Full’ this means that your Recruitment Target has been reached. In other words, that number of participants have entered your Experiment. This means that some of your participants have not completed the Experiment and are still ‘Live’.

If your participants have been Live for a large amount of time, you may need to manually reject them in order to allow more participants to enter the experiment and complete your recruitment target.

For information on how to do this, see the How To: Participants guide.

My experiment doesn't work even though separate nodes seem to work fine!


This question is linked to another troubleshooting example here.

Worked example:

You have set up your Experiment Tree but then realised that you would like to make some changes to your Questionnaire/Task. You go to the Questionnaire/Task Builders, make changes and committ new versions. Sometime later, perhaps when previewing your experiment before launching it, you notice your experiment is not running as you would expect it (e.g. the task works differently to what you have just committed in the Task Builder)!

A quick check you could run is to see whether all nodes within your Experiment Tree are up-to-date, according to your latest commits within the Questionnaire/Task Builders. Experiment Tree does not update nodes automatically - changes need to be applied and committed by you.

Therefore, make sure to keep your individual nodes within the Experiment Tree up-to-date! You could update all nodes quickly by clicking on Utilities -> Update All Nodes in the top right corner of your Experiment Tree Design Tab:

experiment tree update all nodes

Or you could update separate nodes by clicking on each of them and chosing 'Update to latest version' from the Options drop-down menu:

experiment tree update node

I am not seeing data from all the participants who completed my study!


This question is linked to another troubleshooting example here.

Version Picker

Worked example:

Perhaps you are mid-through or completely finished (wohoo!) running your experiment and want to have a look at your collected data. You see in your Participants Tab in the Experiment Tree that 50 participant completed your study (learn more about partcipant progress here) but when you go to the Data Tab you realise there is only 40 people you can download your data for!

Don't worry - in most cases the solution is very simple: you need to look at the accurate version of your data!

Perhaps you are not seeing data from all participants because some other participants completed the older versions of your experiment. If you update nodes while running a live experiment, participants who entered your experiment before you updated your nodes will complete older versions of your Questionnaires and Tasks, while those who enter after you updated your nodes will automatically be assigned to the newest version of your experiment.

Make sure you select the correct version of your experiment's data by choosing experiment version from the Version Picker in the top right corner of your Data Tab! It might turn out that data from those 10 apparently missing participants is ready to download from an older version of your experiment!

experiment tree version picker

Participant Status

Another thing to check for would be participant status - remember that your data is ready to download only for those participants who have the Complete status, which indicates that they have gone through your whole experiment and reached the Finish Node. Participants who are currently Live (because they are still completing your experiment or have perhaps dropped out) will not automatically generate data ready for download yet. This could be done manually by you by including them. Including Live participants will allow you to look at the data they have generated so far at the cost of one token per participant.

participant status Include

Read more about participant status and how to include/reject participants in our How To: Participants guide!


For more troubleshooting on what seems to be 'missing' experiment data see this page. Otherwise, you could contact our friendly support team via this form if you are worried about your data and would like us to have a closer look!


My Branching Isn't Working


I've set up a Branch Node and configured it using embedded data, but participants are all being sent down the same branch.

Here are some reasons your branching may not be working as you expect:

  1. The Property in your Branch Node does not match the key/name of your embedded data.
  2. You are using one Branch Node when your question allows multiple responses.
  3. You have set more than one branch as default.
  4. You have specified the wrong Value in your Branch Node (e.g. entering the correct answer instead of the desired number of correct answers).
  5. You have not updated all nodes in your Experiment Tree.

Here's what to do in each case:

1. The Property in your Branch Node does not match the key/name of your embedded data.

Go to the questionnaire widget or the task screen where you save the embedded data you use in your Branch Node. Copy the 'Key' field (Questionnaire Builder) or the name you entered in the relevant embedded data settings field (Task Builder). Now, go back to your Experiment and paste this into the Property field of your Branch Node. This will ensure that your Branch Node can locate the embedded data.

If this still doesn't work, your embedded data may be set up as Spreadsheet or Manipulation, rather than Static. See the next page for how to make sure you're using the correct embedded data name in each case.

2. You are using one Branch Node when your question allows multiple responses.

Each Branch Node can only handle one exclusive response (e.g. sending participants one way if they answered Yes, OR another way if they answered No, OR another way if they answered Maybe). If you are branching participants based on a widget that accepts multiple responses (e.g., Checklist), you will need to configure one Branch Node for each possible option they could select. You will then need to connect these Branch Nodes together to capture every combination of responses. For an example of how to set up Branch Nodes to capture multiple responses, see this Tutorial.

If your question requires only one response, make sure to use a widget that enforces this, such as Radio Buttons or Dropdown. You will then only need to use one Branch Node.

3. You have set more than one branch as default.

The image below shows a Branch Node set up incorrectly, with both branches selected as default.

two defaults

To fix this, simply untick the Default box on one of the branches.

4. You have specified the wrong Value in your Branch Node.

The Value field in the Branch Node should relate to the data you use to determine that participant's branch. Say you are branching participants who fail an attention check to a Reject Node. Your attention check involves one question, which the participant can either get correct or incorrect. There are a couple of different ways you could set this up.

You could configure the embedded data on the attention check screen to save correct answer count. The value of this data will then be either 1 (if the participant passed the check) or 0 (if the participant failed). In your Branch Node, you should enter 1 as the Value for the Pass group with the rule 'equals', and 0 as the Value for the Fail group, again with the rule 'equals'.

Alternatively, you could set up the embedded data on the attention check screen to save the most recent answer. The value of this data will either match the correct answer (if the participant passed the check), or it will not (if the participant failed). In this case, you should enter the correct answer as the Value for both Groups in your Branch Node, with the rule 'equals' for the Pass group and the rule 'not_equals' for the Fail group.

The important thing is to make sure your Value matches the type of embedded data you are saving: a number if you are saving number correct, or the actual answer if you are saving a single recent answer.

5. You have not updated all nodes in your Experiment Tree.

Setting up a Branch Node can be a multi-stage process, with a lot of edits to Tasks and Questionnaires along the way. In some cases, embedded data are set up perfectly in the latest versions of your tasks -- you just haven't updated all nodes in your Experiment Tree to use the most current versions! Try updating your nodes and see if that fixes the problem.


If you've checked all the above and are still having issues with branching, consult our embedded data walkthrough. Alternatively, feel free to contact us with a link to your experiment and we will happily take a look!


Embedded Data Don't Display Correctly


Here are some common reasons why embedded data may not display correctly:

  1. The key/name you are trying to retrieve does not exist (this results in embedded data displaying as 0).
  2. You are trying to display embedded data in a Zone where this is not currently supported.
  3. Your embedded data values are accumulating over multiple/repeated versions of the same task.

Here's what to do in each case:

1.The key/name you are trying to use does not exist.

If your embedded data displays as 0, check the key/name you are using to retrieve it. For embedded data from a Questionnaire, this must exactly match the Key field of the relevant questionnaire widget. For embedded data from a Task, make sure the key/name you are using to retrieve the data corresponds to the way you are saving it.

There are three main ways you can save embedded data in the Task Builder:

  • Static. If you save your embedded data as Static, the name you use to retrieve it must exactly match the name you enter in the embedded data settings field. In the example below, you would use the name 'correct' to retrieve your embedded data.
embed static
  • Spreadsheet. If you save your embedded data as Spreadsheet, the name you use to retrieve it must match the data in the specified spreadsheet column for the trial(s) you are interested in. For example, say you use spreadsheet embedded data named 'correct' to count correct trials separately for different rounds. 'correct' would then be the name of a column in your spreadsheet. Instead of using 'correct' directly to retrieve your embedded data, you would instead use the name entered in the 'correct' column of your spreadsheet for the trials whose correct count you want to display. In the example pictured below, this is 'correct_1' for round 1 trials and 'correct_2' for round 2 trials.
embed spreadsheet correct spreadsheet
  • Manipulation. If you save your embedded data as Manipulation, the name you use to retrieve it must match one of the values of the specified manipulation. In this example, the manipulation 'correct' is given the value of 'correct3' in the easier version of the task and 'correct4' in the harder version of the task. To retrieve the correct count from the harder version (on the right in the image below), you would use the name 'correct4'.
embed manip correct manip

Note that in all these cases, the embedded data key/name is case-sensitive!

2. You are trying to display embedded data in a Zone where this is not currently supported.

Currently, embedded data can be displayed in a Rich Text Zone. There are also ways to use specific forms of embedded data captured by particular Zones: for example, you can use the Audio Recording Zone to save recorded audio files as embedded data, and then play them back by retrieving the embedded data in a Web Audio zone, as shown in this Tutorial.

However, some Zones do not currently support retrieving embedded data directly. For example, you cannot use embedded data directly in an Image Zone to display the participant's most recently selected image on a feedback screen. However, this can be achieved with the addition of some scripting, as shown in this example. Another workaround is to use HTML to embed an image in a Rich Text Zone. In this case, you would use the standard HTML <img> tag with src set to the embedded data name, enclosed as usual in curly brackets and preceded by two dollar signs. For example, if your embedded data is saved as 'image', <img src = "$${image}"> would incorporate this image in your HTML.

3. Your embedded data values are accumulating over multiple/repeated versions of the same task.

If you are using Static embedded data to save correct count, incorrect count, percentage correct, or total trials, and your participants do the same task more than once in your experiment, the counts will accumulate across all versions of the task. The solution for this depends on exactly how the versions of your task are set up in the Experiment Tree.

- If the versions of your task are represented by separate nodes, you need to set your embedded data name as a Manipulation. Details of how to do this are given in the embedded data walkthrough, or in this video.

- If you are using the Repeat Node to send participants back to the same node repeatedly, you need to reset your embedded data on each repeat using scripting. An example of an experiment that does this is available here.


If you've checked all the above and are still having issues with embedded data displaying incorrectly, consult our embedded data walkthrough. Alternatively, contact us with a link to your experiment and we will happily take a look!


The Embedded Data I'm Trying to Save is Too Large


During my experiment I get the message 'Warning! The embedded data you are trying to save is too large.'

This warning can occur when trying to save many small pieces of embedded data, where the total size of all the data is larger than Gorilla's internal limit.

There are two main solutions to this problem:

  1. Reduce the amount of embedded data you are saving to only what is essential for the proper running of your experiment. You should only need to save embedded data if it contains information that you need to a) display to participants or b) use for branching.
  2. If you are collecting embedded data across multiple tasks, clear the embedded data once it is no longer required. This example shows how to use scripting to achieve this.

If neither of these solutions work, contact us with a link to your experiment and we'll see what we can do to help!

I See Strange 'Diamond' Characters in my Spreadsheet


As of August 2018, this problem should not occur because Gorilla is now able to interpret special characters in a non-universal format. However, if this does occur, follow the steps below.

This problem is typically encountered when uploading a spreadsheet for your Task in a csv format.

Explanation: This problem occurs because, in many programs like Excel, csv files are not saved using UTF-8 encoding by default. This means that these files don’t save special characters in a way that can be universally understood and recognised. When they are uploaded to Gorilla, because the special characters aren’t readable, they are instead replaced with the diamond with a question mark symbol which looks like this: �.

Solution: The way to resolve this is to save your csv file as a XLSX or ODS file, or as an 'CSV UTF-8 (Comma delimited)' compliant one.

Steps:

  1. In your spreadsheet creating program e.g. Excel, use ‘Save As’
  2. Under 'Save as Type': Select the CSV format that indicates UTF-8 compliance. In modern versions of EXCEL this is ‘CSV UTF-8’, or ‘xlsx’ or ‘open document spreadsheet.
  3. Upload your reformatted spreadsheet to Gorilla and your special characters should now be viewable.

Older versions of EXCEL (2013 and earlier) don't directly offer a 'CSV UTF-8' file format. If you still wish to save this as a CSV, follow the steps below:

  1. Under 'Save as Type' select the csv format.
  2. In the tools menu, select 'Web Options', then 'Web Encoding' and then select 'UTF-8'.

If you are using an older version of EXCEL and trying to resave a csv file to use UTF-8 encoding, the above steps do not work reliably! In this case:

  1. Open your csv file in Notepad (NOT Notepad++) and use 'Save as'.
  2. Select 'All files' in the File Type drop down - this will keep the file as a csv.
  3. In the encoding drop down, select 'UTF-8'.

This will then convert your csv file to use UTF-8 encoding.

Warning

In most file explorers, you won’t get an indication of whether a csv has been saved as UTF-8 or not.

Further, the default for most spreadsheet programs is to save the csv as a normal (non-UTF-8) CSV, even if this is a previously UTF-8 compliant CSV that you’ve downloaded from Gorilla.

Always make sure it is being saved in the UTF-8 compliant format if you are using special characters!

All my Metrics are in One Column


There are two main reasons for this issue:

  1. When resaving a CSV metric file within Excel, Excel can default to saving your file in Unicode Text format, which will result in a loss of formatting.
  2. Your computers 'local' settings for reading CSV (Comma Separated Value) files is 'non-standard'. This means that Excel cannot work out where to separate out the metrics files correctly.

Here are the solutions for each case:

  1. When you save your metrics upon downloading your data, sometimes the default file-type selected by your computer will be something other than CSV. Often it defaults to 'text-file' instead. This can cause problems when you then open this file later to view the data.
    This issue is easily fixed; re-download the data from your node(s) and check that the file-type is one of those previously listed before saving your data.
  2. CSV (Comma Separated Value) files can use a variety of syntax to act as column separators, or to denote number formats. The defaults of these values can vary across computers. While Gorilla is able to accept variations of CSV syntax when you upload a spreadsheet, via the 'encoding' and 'separator' settings it has no control of your computers local settings. In this case even though you are sure that you have saved the file as CSV your local spreadsheet reader is not able to read the content correctly. Instead, download a CSV (Semicolon) or CSV (Tab) file.

For those who have downloaded the data file prior to August 2018:

The solution for this issue is to change your computers local 'Delimiter' settings. Please refer to the instructions below, appropriate for your operating system.

Windows-7

Step 1: Click the Start button, and then click Control Panel

Step 2: Click on 'Clock, Language and Region' menu section.

troubleshooting change delimiter 1

Step 3: In this sub-menu, click 'Region' to display the Region 'dialog-box'

troubleshooting change delimiter 2

Step 4: Click Additional Settings button, to open the Customize Format 'dialog-box'.

troubleshooting change delimiter 3
Step 5: Change your settings to match those shown here:
troubleshooting change delimiter 4

Windows-10

The instructions for windows 10 are identical to Windows-7 with one exception:

Step1: Locate the Control Panel by typing in 'Control Panel' in the Start Menu, search bar.

troubleshooting change delimiter win10

My Metrics Appear 'Out of Order'


Some metrics appear in a different order in my data between participants

Explanation:
The most common occurance of this issue is found in Questionnaire metrics.

Downloaded metrics are, among other things, ordered by UTC timestamp, which is the time the metric is received by our database. For Questionnaires, because all of the responses in a Questionnaire are collected and uploaded simultaneously, individual responses can sometimes arrive at the database at slightly different times. This can result a participants responses appearing a different order to other participants. The same can occur for tasks, where metrics that are uploaded very close together can sometimes appear in a different order than would be expected.

Solution:
In both cases, there is no change necessary nor cause for concern.

If you wish you can reorder your metrics within Excel based on Local Timestamp (which is the time the metric was initially recorded on the respondents device) rather than UTC as this may mitigate the issue.

Numbers in my Data Don't Make Sense


Looking at numerical data recorded from your experiment, the numbers seem to be too big, too small, or contain multiple decimal points, making them impossible to interpret.

Explanation: This problem may occur because of regional variation in the conventions for decimal and thousands separators.

When numerical data such as reaction times are recorded in the browser, they are always encoded with the full stop/period (.) as the decimal separator and the comma (,) as the thousands separator. This is what will be uploaded to Gorilla's data stores. However, in many European countries, the roles of these separators are reversed - the comma is the decimal separator and the full stop is the thousands separator. As a result, when opening a data file expecting this encoding type, the numerical data may be parsed incorrectly.

Solution: To resolve this, you can take the following steps:

  1. Generate and download your data file as a CSV. Using this text-based format should prevent any local assumptions being forced onto the file.
  2. Open a new file in your spreadsheet program and select the 'Import from text/CSV' option.
  3. When importing the data, there should be an option to specify the decimal and thousand separators. Set these to full stop and comma respectively.

Alternatively, your spreadsheet program's advanced settings should include an option to manually specify the decimal and thousands separators.

Participants' Reaction Times Look Odd


One of my participants reaction time metrics are much shorter/longer than I expect should be possible

Explanation:
In order to accurately measure and record a participants reaction times Gorilla must be the active window, at all times, while the participant is undertaking your Task. If the participant navigates away from Gorilla - by switching to a different tab/browser or opening and using a different programme - while undertaking your Task this can lead to inaccurate recording of their reaction times.

This behaviour will be clearly discernible to you in your metrics as a distinct set of reaction times: typically a reaction time much longer than usual followed by a series of shorter reaction times (See the image example below).

Participant behaviour such as this is an example of 'divided attention'. It indicates that the participant is 'distracted' and is not paying full attention to your Task. As such you will probably want to take this into account in your analysis or else redesign your task to mitigate such behaviour - see our suggestions below.

You will likely only encounter this behaviour if your task has lots of time-limited screens back-to-back. i.e. Screens which are set to auto-advance the participant after a set time and which do not require participant input/response in order to advance.

Example of typical 'distracted-participant' reaction time pattern:

troubleshooting reaction times odd

Solution:
While you cannot force participants to stay focused on your task there are improvements and changes you can implement in your tasks to reduce the likelihood of such participant behaviour.

Here are some suggestions:

  • In your instructions before your task ask participants to keep Gorilla as their active Window. Explain to your participants how it may effect their recorded results if they switch tabs or open and use other programs while undertaking your task.
  • Avoid using multiple Time-limited sections back to back (multiple screens which auto advance after a set time.) - This has a tendency to discourage participants from taking part if they realise they do not need to interact with your task in order to complete it. Instead split time-limited sections up into blocks of trials with break intervals in between. Make sure these break intervals are advanced manually (for example; with a continue button).
  • When using Time limits on response screens (to auto advance participants who answer too slowly) make sure you pilot different time limits. Setting a limit which is too short for the average participant can make the task too difficult for participants causing them to give up. Again, split time-limited sections up into blocks of trials with break intervals in between. Make sure these break intervals are advanced manually (for example; with a continue button). This allows participants to 'catch their breath' if the task has gotten too difficult for them.
  • In your experiment tree use performance branching to reject participants early on who do not meet your threshold for accuracy on your task. You can find an example of performance branching here.

Duplicate Metrics


As of October 2017, improvements to the system for recording metrics means that duplicates are no longer loaded into your results. You should no longer see duplicate metrics appearing in your data download for participant data gathered from October 2017 onwards. Note that we still carry out the safety check described below to make sure that you collected data is stored successfully.

If you believe you are still experiencing this problem please get in touch with us via our contact form


When the browser is uploading metrics to the server it expects to receive a message back saying the metric was uploaded successfully. If it doesn't receive this message, it will retry after a timeout as a failsafe. Sometimes, the server is just being a bit slow or the participants internet connection is unreliaable, and so while the first metric did get stored just fine, the browser thinks that it might not have gotten there, and so tries again. This then results in two entries of the same metric. In these cases, we think it's most scientifically appropriate to just disregard the later values.

The participant hasn't see the trial twice, it is simply that the metrics have been uploaded to the server twice. The metrics are identical, so just delete one of the rows.


As of October 2017, a rare edge case was found where a participant with a poor internet connection could refresh on the final screen of a task, while loading the next part of the experiment, and receive the final screen again. This edge case has now been resolved and should no longer occur.

As of August 2017 we have improved how Gorilla records a participant's progress through a task. As a result it should no longer be possible for participants to see a trial twice; due to their having lost connection (e.g. poor internet connection) with the server. As a result the metrics data should not contain repeated trial metrics.

If you believe you have found repeated trials in your data where you are not expecting them, please get in touch with us via our contact form


For Data collected before August 2017:

If a participant's connection fails during the experiment, they can fail to synchronise their current progress through the task. When they then refresh the page, they go back to the last point at which their progress was synchronised, which may be earlier in the task.
Typically, at the start of the last trial. This can lead to some trials appearing twice or metrics appearing to be out-of-order.

In this situation the participant has seen the trial twice, because the participants connection failed, their progress wasn't saved to the server as the server has no way to know where the participant was. In these cases, we think it is best to use the responses from the first exposure to the trial.

Missing Metrics


There are a couple of reasons why it can look like you have missing metrics:

  1. Check you have 'Included' all participants on your participants page.
  2. Check you are downloading data from the right 'Version'.
  3. Are you sure the participant completed all parts of your Experiment?
  4. Did you use any Experiment 'Requirement' settings?
  5. Other issues?

1) Have you checked to make sure all the necessary participants are 'included'?

When a participant is 'included' their data is added to your available metrics download. A participant is included automatically when they reach a finish node and Complete your experiment. However, by default, participants who are still 'live' i.e. still working through your experiment, are not included and their data won't appear in your download. If you want to include the data from participants who are still live, go to the Participants tab on your experiment, click the 'Actions' button on a participant and select 'Include.' Alternatively, you can use the 'Force Include All' option to include everyone. Note for Pay-per-Participant users: remember that including a participant consumes a participant token and this process is irreversible. Make sure you only include participants you really want the data for and purchase more tokens if you need to.

2) Are you looking at the right version of your experiments data?

Participant data is associated with a version of an experiment. If you made any changes to your experiment during data collection, your data will be split across the different versions of your experiment. For example, your overall participant count may be 40 but 20 of them were collected in version 2 of your experiment and another 20 were in version 3. To gather the data for all fourty participants, you would need to download the data from both version 2 and version 3. To change the version, you are currently downloading from, on the Data tab, select the appropriate version from the Version Picker. To see what versions of your experiment your participants saw, go to the Participants tab and review the contents of the Version column.

3) Are you sure the participant completed all parts of your experiment?

Not every participant will complete the whole of your experiment! At any time, a participant has the right to withdraw and you will receive no notification of this, other than a sudden stop in the metrics and the participant status remaining 'Live'. If a participant’s data seems to stop part way through a task, check to see if data from that participant appears in any later stages of your experiment. Try to find that participants unique private or publicID in later questionnaires/tasks. If you can't find them there then they most likely decided to leave! All experiments will experience some form of attrition and there is little that can be done to prevent this, unfortunately.

4) Did you use any Experiment Requirement settings?

If you choose to restrict participation in your experiment via any of the requirements set on your experiments recruitment page. i.e. Restrictions based on Device Types, Browser Types, Location or Connection Speed. Participants who enter your experiment but whom fail to meet your specified requirements will not see any of your experiment and will therefore have no metrics recorded.

If you wish to calculate the number of participants being rejected via your selected experiment requirements use a checkpoint node directly after the start node(s) of your experiment. For pay-per-participant accounts holders, we recommend using this method if you wish to determine which 'live' participants you may wish to reject and which you wish to include.

5) Have you tried all the solutions described above?

If you have reviewed and tested all of the solutions listed on this page and they have not resolved your issue, contact us via our contact form and we'll look into it for you as a matter of priority.


My Data Still Haven't Generated


In the vast majority of cases, data generation in Gorilla is very fast, taking only a matter of minutes. However, in some circumstances, data generation can take longer.

Explanation: At any given time, Gorilla is handling a lot of requests for data. At particularly busy times, a queue can form, leading to longer-than-expected wait times before your data are ready to download.

Solution: If it's been 24 hours and your data have still not generated, contact us and we'll look into it for you!

My Code Won't Run/Doesn't Work


If your code doesn't work as you would expect it, visit our Debugging Guide for useful steps on how to troubleshoot this!

For more information on how to use Gorilla Code Editor see this guide.

For information on how to script in the Task Builder see this guide.

The Message 'Please Switch to Landscape Mode' Won't Go Away


If your participant receives a 'Please switch to landscape mode' message when completing your task on mobile and this doesn't go away when the phone is rotated, there are two common explanations.

  1. Your participant has auto-rotate locked on their phone. This means the phone, and therefore Gorilla, will not switch to landscape mode when the participant turns their phone. To continue with the task, your participant needs to turn this off. We recommend that when recruiting via mobile, you ask participants to turn auto-rotate lock off before they begin the task.

  2. Your participant has opened the experiment link through an app, such as Facebook or Instagram. This may open the link inside the app rather than within a full browser, and this may not be able to pick up on phone rotation. We strongly recommend that when recruiting via mobile, you ask participants to copy-paste the link into their browser.

Beta and Closed Beta Zones


Beta Zones are new zones that have been released for public use, but that we intend to make improvements to before they are considered ‘finished’. We cannot guarantee that they will work without fault, and suggest that these be used in addition to our other zones, rather than instead of.

Closed-Beta zones are available ‘on request’ only. These zones are an early implementation of the feature, and have not been thoroughly tested on across all browsers. Access is given on the understanding that you will provide us with feedback on any bugs as soon as possible. Please also let us know if there’s something you’d like to be added to the zone.

Closed-Beta Zones may have limited support information available, so along with use of the Closed Beta Zone, you will be given access to a project containing a quick tutorial or example of the zone so you can see how this feature is set up, and, if desired, clone the example for your own use.

I you would like access to a closed beta zone, you should use our contact form.

Other Issues


In the first instance, try using Gorilla in Chrome. We are committed to supporting all browsers, but some bugs may get through our testing.

If you find a bug (which then doesn't happen in Chrome), we would be immensely grateful if you could fill out the Support Contact Form with details of the bug and what browser you were using as this will help us address the issue! We won't be able to fix it right away, so use Chrome, but it will get it fixed as soon as possible.