If you have a question not covered by the list below, do not hesitate to contact us.

I get an error: "Keyword not recognised".

This usually results from using a new feature in an old version of the PIEL Survey app. Simply update the app and the problem will be solved. It also could mean that one of the keywords in the control file is misspelled. The error message identifies the wrong keyword.

How do I create a scheduled survey?

A scheduled survey survey requires a minimum of 3 settings in the survey control file.

  • "can-run-once" must be "0" (or just delete this line from the file as it is the default)
  • "run-for" specifies how long the survey will run for
  • "run" determines what days the survey will run on and at what times

For example, the following lines in the control file will create a schedule to run for 7 days. It will run at 9:00am on Monday and a random time between 9:00am and 10:00am on Tuesday. It will also run every day at 5:00pm.






If the above survey is started after 9:00am on Monday, the survey will not start until Tuesday. The first Monday on which a notification will arrive will be next week. If you want a survey to be run on a Monday, you must either allow at least 7 days to reach Monday next week. If you want it to run on a specific Monday, ensure that participants start the survey before the first schedule.

Note that a scheduled survey will not start if the "run-for" period is not long enough for the app to reach a scheduled time in the future.

You can also further customize the behaviour of the app with these settings: start-date, exit-message, placeholder-message, alert-sound, max-delay and max-duration. Please refer to these instructions.

A useful setting while developing your scheduled survey is to allow testing as follows, but we recommend that this be set to "0" or removed before sending the survey to participants.


I am not receiving notifications

Since the notifications are sent from the device itself, there is no need for an internet connection to receive notifications.

There are some key user actions which could prevent a user from being aware that a notification has been sent. Most of these might seem obvious but if a user is having problems, it is worth checking anyway.

  • Double check that a scheduled survey is still underway (it may have finished). You should see a placeholder screen if it is running.
  • It may be that the survey will start tomorrow. If you start the survey after the first time schedule, it won’t start today, it will start tomorrow. This is intentional by design, so only full day schedules will be run. Thus it might appear that there are no notifications but they will come the next day.
  • Ensure that the device is not muted or the volume turned down.
  • Check that notifications are authorised for the PIEL Survey app. The app actually checks for this when the survey is started but does not check again. Disabling notifications for the app will prevent it working as expected.
  • Don't leave "Do not disturb" on for long periods and if you need to do so, exempt the app.
  • Check that the time setting on the phone is correct.

For further information, please refer to these instructions.

I can't send the data file by email

On an Apple device, the PIEL Survey uses the Apple Mail app to send the data file. This is automatically shown when the user chooses to send the results.

Please ensure the following:

  • Check that a valid email address appears in the "To" field. If not, the user can manually enter an email address.
  • You must also have an email account that is enabled.
  • Send a test email from the mail app to verify that the account is working.

The participant can also choose to use the Share option and choose another method of sending the data. This option is shown by tapping the blue "Action Arrow".

Can I run multiple scheduled surveys at once?

This is not currently directly possible but may be in future. However, a similar effect can be achieved by having a scheduled survey with a branching question.

In the example below, a question is asked: "What time of day is it? Branching is then used to deliver the correct set of questions. Note that each set of questions must end with a "list" or "checkbox" type question and each response for that question must have "%NEXT END". The exception is the last set of questions where any question type can be used and no "%NEXT" is needed.

1|What time of day is it? %TYPE list|Morning|Afternoon %NEXT 4

2|This is morning question 1 %TYPE checkbox|Response 1|Response 2|Response 3

3|This is morning question 2. %TYPE list|Response 1 %NEXT END|Response 1 %NEXT END|Response 2 %NEXT END|Response 3 %NEXT END

4|This is afternoon question 1 %TYPE checkbox|Response 1|Response 2|Response 3

5|This is afternoon question 2 %TYPE list|Response 1|Response 2|Response 3

Can I create an "End of day survey" with a scheduled survey?

This is not currently directly possible but may be in future. However, a similar effect can be achieved by having a scheduled survey with an initial branching question. For example, the first question could be "Is it after 7:00pm now? If the answer is yes, the end of day questions could be presented using branching logic. If no, the normal scheduled questions are presented. This requires that you first explain the choice to participants. For an example of how to to this, see the answer to the FAQ "Can I run multiple scheduled surveys at once?".

Is participant data secure?

The PIEL Survey app has a number of layers of protection of confidentiality. While the data is on the mobile device, the user controls security using normal device security measures for that device. There is no server used for data storage. Email transmission using normal secure methods (SSL or TLS) also provides a high level of security that users usually regard as acceptable.

Research projects using the app have been approved at universities and research institutions around the world. For more information see our confidentiality information.

Can I use "piping"?

The PIEL App does not offer "piping" directly, but you can achieve much of the same functionality using branching logic. Below we show an example of the question section of a Control file to demonstrate how to achieve this. A list question is used to branch to the desired group of questions, which contains customised text. Each group of customised questions must end with a list question which branches back into the main logic flow of the survey.

1|This is question 1 %TYPE list|Answer 1 %NEXT 2|Answer 2 %NEXT 5|Answer 3 %NEXT 8

# Group 1

2|A text question about Answer 1 %TYPE text

3|A checkbox question about Answer 1 %TYPE checkbox|Answer 1|Answer 2

4|A list question about Answer 1 %TYPE list|Answer 1 %NEXT 11|Answer 2 %NEXT 11

# Group 2

5|A text question about Answer 2 %TYPE text

6|A checkbox question about Answer 2 %TYPE checkbox|Answer 1|Answer 2

7|A list question about Answer 2 %TYPE list|Answer 1 %NEXT 11|Answer 2 %NEXT 11

# Group 3

8|A text question about Answer 3 %TYPE text

9|A checkbox question about Answer 3 %TYPE checkbox|Answer 1|Answer 2

10|A list question about Answer 3 %TYPE list|Answer 1 %NEXT 11|Answer 2 %NEXT 11

# Back to main logic flow of the survey.

11|Last question|Answer 1|Answer 2

Can I use other languages?

This encoding of the PIEL Survey app is extremely flexible and will allow a wide range of language scripts to be used. You can use your preferred language in questions, responses, placeholder messages and exit messages. It will even accept emojis.

The PIEL Survey itself is available in English, Arabic, Catalan, Chinese, Dutch, French, Italian, German, Norwegian, Spanish and Turkish. We plan to add languages in the future. If you want your language added, you can accelerate the process and help us by providing translations of the key words and phrases. Please contact us if you wish to help.

At the request of Chinese users who do not have access to Google Play, we have provided a direct download of the PIEL Survey app for Android. If you have access to Google Play, we strongly recommend that you use it for installing the app, not the direct download option.

Please note that editing "right to left" languages like Arabic can present challenges in text editors. The mixture of English keywords and Arabic can cause text editors to change the position of words in ways that are hard to control. This type of software tries to display the mixed text in a way that is decided by complex algorithms. We expect that users of Arabic will be used to these issues. We are not able to provide free support to create these files but have the following advice.

  1. Use explicit question types. If the type is not specified, the default is a list question. However, it seems to be easier to use the formal "%TYPE list".
  2. A similar consideration applies to the use of %NEXT in list and checkbox questions. %NEXT defaults to the next question if it is not specified. However, the use of "%NEXT x" where "x" is a question number often helps the editor to handle the format properly. We recommend using it even when referring to the next question.
  3. Use cut and paste for the editing. Using the forward and back key can sometimes be unpredictable.

How can I set multiple random survey schedules in one day?

Yes you can, but the app does not allow you to set multiple random survey schedules in one time period. The reason is that they could arrive close together and annoy your participants. Instead, you can set multiple random time periods in a day with a gap between them so they do not arrive too closely together. In the example below, 3 random schedules will arrive each day in the preset time periods for 7 days. There will be at least 1 hour between notifications.