🤔 Ask Anything Thread (Newbie Friendly)

Hi, Tim:

If I am including how much participants will be paid in the study description (on Prolific and in the Qualtrics survey) and in the consent, should I post the “how much do you want to pay them” rate (e.g., $3.00 in the screenshot example) or the hourly rate (e.g., $12.00/hr in the screenshot example)


In the example shown, participants will be paid $3 for an estimated 15 minutes of their time ( which works out as $12 per hour if they were to do the survey 4 times which they can’t so it is only hypothetical).

So I would only mention the $3 in the consent form.

I would also start with only a few participants and then “add places” from the action menu later because you may find that participants take less time that you had estimated.


Thank you, Tim. I appreciate the tip of starting with only a few participants to gauge completion time, then increasing to my target sample size.

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Hi, dumb question on the balancing settings.
I’m running a study with multiple experimental lists. For each list, I created a different study on Prolific and I balanced it for sex.
Problem is that I have an odd number of participants for each list. So my balance sample is always 3 male/2 female. Which is ok for the single list, but it’s a problem on the long run (the whole experiment will end up with way more male than female participants).
Do you have any idea on how to revert the default settings and have 3 female/2 male every now and then? I read on the Help Center that it is possible to manage the options of the balanced sample, but I cannot see the “Manage options” button any longer.
The only idea I came up with so far is running an unbalanced study, open to only 3 participants, screened for female, and then add 2 extra spots. But I’m quite sure that at that point I cannot screen for male participants only.
Creating two different studies (one for male, one for female participants) for every list doesn’t seem so convenient either.
Any better suggestions/clue on where the “Manage options” button ended up?

Hi @Jon and @Josh . I’m experiencing Error Code 500 and am completely unable to access my account as a result. I put in Support Request 236524 about this as well. Thanks in advance for your help!

Dear EE_Lab

Welcome to the forum :slightly_smiling_face:

I am afraid that more than one researcher (though a very small percentage of all those using the platform) has had a similar issue as reported on this thread

So far, only support and time has been able to resolve the issue.


Dear Dod

Welcome to the forum :slightly_smiling_face:

I am sorry to be slow. It is the end of term.

This is not a dumb question at all, at least as far as I am concerned since I did not know that there was a manage options button that as you say, is definitely there in the screenshot on the balance for gender help page

But now it is definitely not there.

I can only suggest support, a feature request for the return of the feature, and multiple (male and female) studies.


Hi Tim! Thanks!
At least now I know that it’s not just me not seeing the option any longer.
And yes, I’m duplicating each list (one male/one female). But it slows down the work flow a lot - I have to wait for each list to be done before opening a new one and screening out participants.
Thanks for reporting it to the support!

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Dear Dod

I am afraid I have not reported your issue to support. I think you have already contacted support, but if you haven’t then please do.

I have however added a feature request to these forums here below

but Prolific have retreated from the forums (!) so I am not sure if voting for it will have any effect!

Please come back Prolific m(._.)m


Hello! I’ve got a couple of questions about invoicing:

  1. is it possible to combine multiple invoices into one overall invoice?
  2. Does Prolific charge different amounts for balanced and representative samples for the same sample size? If yes, why is this?

Some info about our study: we were originally going to use a representative sample, but after reading Prolific’s study requirements, we realised we needed to use a balanced sample option, because we only want pet owners to respond. We are therefore screening for pet ownership, since instructions state that we should not use the participant information sheet to screen. We are balancing 50% males and females and have created three separate sub-surveys by age group so that we get a balanced sample by age. We want 500 participants, and based on the UK census breakdown, we have (roughly) 170 in three groups (18-37, 38-57, 58+). Based on the Prolific documentation, creating three sub-studies like this seemed like the only way to screen for pet ownership while maintaining a representative sample for age and gender (if there is a better way to do this, please let me know). However, we now need to raise three invoices instead of one (hence question 1) and these do not add up to the same amount as for the representative (non-screened) sample despite adding up to the same number of participants (hence question 2). Thank you for your help! :slight_smile:

Yep, I meant the feature request. I had no idea prolific had retreated from the forums! I knew they were under personnel this week, so I thought that I had more chances of finding a solution by writing on the forum (if someone had already experienced a similar problem).
I’m gonna drop a message to the support immediately!
Thanks again

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Hi Laura

Welcome to the forum :slightly_smiling_face:

I am not a member of Prolific so things related to money scare me a bit, please take all the following without gaurantee and only as far as I guess.

  1. I don’t know of a way to combine invoices. I have just mentioned the two ways that one should be able to get invoices (from the payments in end and from the study payments out end but the latter was greyed out for me) here
    Study receipt not showing service fees - #4 by timtak

  2. Yes, representative samples (which include gender, age, and race representation) come with a separate charge, whereas if you make your own as you have, using balanced genders samples (which do not incur a charge anymore) and age groups then that costs no more than the standard prolific fee.

Please see
“we charge an additional fee in addition to our standard service charge”

I don’t know of a better way to achieve what you are doing, and your way seems really good.

I hope that helps!


Hi Tim, Thanks very much for taking the time to reply- good to know about the different fees for representative samples, and that it’s not a bug! I’ll have a look at invoicing, but I think you are right, there may not be a way to combine. I’ve dropped a message to the Prolific team and am awaiting a reply as well. Thanks for keeping this forum going! :slight_smile:

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Hello Folks,
I very much like the new interface, and the workgroups. But, under Financing, I am missing all but my most recent paid invoice. Anyone know where I can find those?

Dear DrJBN

Welcome back.

I just had a look at my finance invoice list and all the invoices I have ever paid are there.

I tried creating a new workspace to see if that affected things but invoices for payments are not under the workspace heirarchy so even with the new empty workspace selected my finance tab (left hand item) shows the same set of invoices that I have paid since joining Prolific.

Since yours are missing, I guess it is a bug, or at least requires the help of Support.



Hello! :slight_smile:

I recently ran an study, opened 182 spots for participants, but in the end only collected 172 and I’m happy with that amount. Every time I increased places I saw prolific already took the money from the budget to cover for it. However, now I finished the study, and I wonder if Prolific will return the money for the 10 participants to the budget immediatly (did not happen) or whether I should send any message to support.

Thank you for the help in advance!

I was wondering whether you share somewhere information on the type of studies that are posted on this platform? I am particularly interested in the average and median duration of the studies.
Thank you so much and best wishes,

Dear Vii

Welcome to the forum.

When you have stopped the study, the participants have been approved, or the rejection process has been completed and your study moves from the active to completed tabs, then the budget tied up with the study (i.e. the remaining unfilled places) will be returned, as far as I know. So imho there should be no need to contact support, and they tend to be busy.

To the best of my knowledge,


Dear Manuela

Welcome to the forum :slightly_smiling_face:

I had a look through the posts to the Prolific Blog



Find out how to run higher quality research online and how Prolific can help.

But I couldn’t see any information about the length of studies.

If you message me with your affiliation and you are an academic researcher and can provide anonymity I can send you data regarding the studies i have participated in.



I’m wondering how limiting the time participants have to complete my study works. As a participant, I’ve seen a counter on the Prolific page that shows you your ID.
Can I as a researcher change that counter’s starting point, or is it automatically calculated based on my estimated study duration?
What does that counter actually do? (Automatically reject submissions, forced-returned submissions, etc)