On Prolific, it is important to redirect participants back to the Completion URL found on the study creation page, or provide them with a completion code.
The will look something like:
where 'I2PWSFRG' is the completion code.
Participants will visit this URL, or enter the code, to prove that they have completed your study. Therefore, this code should only be given to the participants who submit a complete and valid response to your survey.
Please make sure that participants' data has been submitted to your survey software (e.g. Qualtrics, SurveyMonkey, Gorilla etc.) before participants will have access to the completion URL/code.
There are two ways to provide a completion URL/code:
A) [Recommended] via automatically "Redirecting to a URL". Some software such as Qualtrics, SurveyMonkey, and others support redirecting to a URL at the end of each submission. In this case, simple insert the "Completion URL" provided by Prolific as the redirect URL, and participants will automatically be returned to Prolific upon successful completion.
B) via a "Custom end of survey message". If it's not possible to redirect participants automatically back to Prolific, you can also manually include the completion URL/code at the end of the study, and ask participants to copy and paste the code into Prolific. For example, with Google Forms go to "Settings" -> "Presentation" and edit the confirmation message to include the completion URL.
You can use the completion URL/code we provide you when you create your study, or you can use your own custom code. Please use the "Preview" function to check that this is working smoothly before launching your study.
Please note that submissions marked with an incorrect completion code (such as NOCODE) are not necessarily invalid. Read more about the reasons why this might occur here: Problems with the completion URL (NOCODE or incorrect code submissions)