Responses to a survey can be limited using Automatic Quota Control. For example: If you want 75 responses for you survey then you can set this up under Automatic Quota Control. Go to:
Login » Surveys » (Select Survey) » Security
Enter Survey Quota and once you receive the set number of completed responses, no further responses will be accepted. An inactive survey message will be displayed on the survey once the quota is reached. This message can be edited by clicking on the Inactive Message link.
Note: If you have "Branching" and "Termination" enabled in your survey, the count represents the total number of users who have completed the survey *without* getting terminated ie. gone through the last question of the survey.
I had set quota control however, I have received more responses than the set quota.
Quota Control is activated only once the set number of Complete Responses are saved. If respondents have already started taking the survey and while they are completeing the survey the quota is reached, they will still be able to complete the survey. This is the reason why there might be slightly greater number of completed responses than the quota set.
How can I disable Quota Control?
By default Survey Quota is set to 0. Survey Quota = 0 allows unlimited responses to the survey. If you have enabled Quota Control and later on wish to remove it, update the Survey Quota value to 0.