YES/NO Questions

I cannot analyze my YES/NO questions in the report of my survey. There is not any of my YES/NO questions in the options where I add a chart. How can I add the number of answers in a chart ?

I am waiting for your answer ASAP

It is not possible to create a Chart for Yes/No Question field. You can use the Single Chose field instead. 

Well I didn't know that I can't do that. If I knew, I would use Single Choose form instead. I cannot reach the same amount of participant. Is there any way that I can convert YES/NO questions into SingleChose ?

Unfortunately, there is no way to convert fields, the only alternative is to hide the current field to avoid losing the data and add a the new one so you can use that on the report.