Sometimes you may notice that you have open Quota cells but respondents have somehow become Overquota'd for them, especially as you get closer to filling the cell.

The way the Quotas work, when a respondent reaches the point in your survey where you have the quota element they are checked against the cells to see which they qualify for.

While they take the survey, they hold a marker which represents that cell, so that they fall in place when they finish the survey.

If the respondent were to terminate or otherwise exit the survey in any way other than as a Qualified record, then the marker they were holding is released and available again.

Let's take an example of having 49 out of 50 slots full.

For this example, you have 2 respondents, A and B.

Respondent A enters the survey and starts answering questions, eventually reaching your quota element and qualifying for the open cell.

Respondent B enters your survey a few moments later, and starts answering with equal enthusiasm.

Since your quota only has 1 slot open and Respondent A already is holding that marker, the quota is read as full and so Respondent B is terminated as Overquota, to help avoid your quotas going over your set limit.

Now, let's say Respondent A decides that the survey is taking too long and elects to drop-out turning into a partial record, or is terminated.

Suddenly, you still have that cell at 49 out of 50, but with an Overquota respondent too.

As you get closer to filling your quotas, especially if you have a number of respondents taking the survey that would qualify at once, the likelihood of getting Overquotas due to terminating or partial respondents holding markers increases.

From my experience, this is typically the reason you may have Overquota'd respondents when you still have open cells to fill.

Other possibilities may be that the quota cells were edited (to increase the limit for example, and so the Overquota'd respondents were from when the previous limit was set), or that respondents were deleted/disqualified (so the cell was full, but some respondents were removed from the table after other respondents were Overquota'd for the same cell).

Hope this helps!