There's a few reasons why submissions that are recorded in Prolific might not recorded in your survey/study data.
1. The response may be 'in progress'.
In some software, some responses get recorded straight away, while others are temporarily stored as "Responses in Progress". Sometimes, participants finish the study, but don't click on the forward button on the last page, so their responses are temporarily stored under "Responses in Progress", even though they are de facto complete. To resolve the situation simply click "Close Responses" or similar. Afterwards, the responses should show up in your data.
2. The participant may have more than one submission in your study data (but only one in Prolific).
In this case you can just delete the duplicate submissions and approve the participant's submission. Please see our article on duplicate submissions here.
3. If the participant does not have the correct completion code like the rest of the respondents, then something might have gone wrong during the study which caused them to leave early and submit with "NOCODE".
You can find more information about NOCODE submissions (and how to manage them) here: Problems with the completion URL (NOCODE submissions)
Check if you received any communication from participants about any issues, or send them a message. Ask if the participant is willing to take the study again, or accept partial payment. If you don't hear back you might have to reject this submission.
4. If the participant has the correct completion code and has completed in the correct time then your survey software might have had some data loss.
Check with the participant/and or your study software provider if anything went wrong during the study. If the participant took the time to complete the study, you will still need to approve them even if you don't have the data.
5. Please note that in some survey softwares (such as Google Forms) submissions aren't auto-saved, whereas in others (like Qualtrics) they are auto-saved.
In the former case – when responses aren't auto-saved – it is very important that participants click on the final button for their responses to be recorded. Please instruct your participants to both click on the completion URL and to click on the final button on the last survey page.
6. If you're using Qualtrics, there is sometimes a delay for responses to display in Data & Analysis.
This is because they organise responses in their own way to make it easier for you to analyse the data. The process usually only takes a few minutes, but sometimes it can take much longer, especially if there are a lot of responses being collected for the same study.
7. There is also an option on Qualtrics to delete 'Responses in Progress' after a certain period of time (e.g. 1 week).
It is very important to not use this option on your survey if you post it on Prolific, as it may permanently delete responses which are almost 100% complete but for a final button press to record the response. If you have missing data which you cannot find after reviewing the above, it is worth checking how this option is set up in your survey.