I assume this is because you want to SUM/AVG the results, so would changing them into numbers work?
WHEN 'yes' THEN 2
WHEN 'maybe' THEN 1
WHEN 'no' THEN 0
If you just want to count them, then you can just use 'Number of Records' and then bring [Response] into the Row/Shelves. Or if you wanted a COUNT of, say, 'yes' you can create a field [Count Yes] SUM(IIF([Response] = 'yes',1,0)), with similar logic for 'no' and 'maybe'
If this doesn't do the trick, can you let me know what you want to use them for and I can have another go?
Using "Number of Records" did the trick! Thanks for the suggestion. I had been overlooking that function.