Hello! We are trying to build a test where participants have to look at two pictures, and decide whether the two pictures depict the same person, or different people. Following, they have to respond using a “confidence scale” where: 0 indicates “Absolutely certain that the two images depict the same person” and 100 indicates “Absolutely certain that the two images depict two different faces indicates”. 

We want to convert their responses on the confidence scale into SAME for scores from 1-50, and DIFFERENT for scores from 51-100. 

As an example for a practice trial, we wanted to tell participants the following:

On this trial you responded "XX" on the scale. As this was between "1-50/51-100" this was converted into a "Same/Different" face response with "higher (if 1-25 or 76-100) or lower (if 26-75)" levels of confidence.

The correct response was "Same/Different" Face. Your response was therefore "Correct/Incorrect".

As an example, if on a trial where the correct response is “DIFFERENT”, a participant entered 45 on the confidence scale, it would mean that their response is incorrect, and that they are very unsure about their decision. 

Another example: If on a trial where the correct response is “SAME”, a participant entered 35 on the confidence scale, it would mean that their response is correct, and that they are quite unsure about their decision. If they were very sure, they would have selected closer to “0” on the scale. 

We are facing some difficulties in converting these scale responses to the mentioned messages. If you have any ideas of how to work this out best, or any suggestions on how to put these messages across to participants based on their scores on the confidence scale, it would be of great help.

Thank you!