If you are measuring any changes in participants, it is important that you ensure that you have some baseline data to compare it with. It is not enough to simply hand out a questionnaire at the end of the project and expect qualitative and quantitative data to be obtained. Examples of the types of questions that you might want to be asking are available later in the document.
This is an area that requires the most thought and it is advisable to seek assistance from psychologists, to ensure that you are collating what you need. Included in this toolbox are some measures that have worked well for BGH.