I have a matrix question with 20 words to which people can answer Yes/No.

The set up shows (in randomised order) one word (statement) at a time, respondents select Yes or No, after which it auto advances to the next word until all 20 have been answered.

I would like to be able to time how long it takes for each statement to be answered so I can do a response time analysis.  The hypothesis being that a quicker response to a question implies more certainty.

Any help would be greatly appreciated.

Thanks in advance