Your data is based on a Quasi-Experiment which involves participants, from your study, providing information which cannot be quantified.  This type of data involves self-reporting, interviews, and focus groups, as well as a multitude of other types. 

How do you begin to evaluate this type of information?

One place to start could be with the Scolari-Sage Publications Software.  This package is specifically designed to assist with the analysis of Qualitative Research.  This site can provide information on surveying, cognitive mapping, content analysis, and qualitative research.

Concept Mapping This is a processes which converts group participant responses from qualitative responses to information which can be evaluated quantitatively.  This type of evaluation is most generally done with focus groups, but can be expanded.