Why do you use four confidence buttons?

It is common survey methodology to use four categories for categorical scales like this. The wording is the result of several iterations - and also the compromise of needs for responsive usability.

Confidence Buttons

It is common survey methodology to use four categories for categorical scales like this. The wording is the result of several iterations - and also the compromise of needs for responsive usability.

The exact wording, especially of the middle two categories, is always debatable but given the general agreement about the outermost buttons, small nuances in how people perceived the middle categories is OK - especially given how we use the data. Also, consistent use is more important within an individual than across individuals, and we have no reason to believe that a learner will change his or her perception of what a label means during use.