Lucia,
If you want to investigate whether one conjecture is better than another with regard to locality, in addition to capturing descriptive accounts, you might consider a mixed method design. There are established mixed method designs. The choice of design will depend on which element you want to emphasize (the quantitative or the qualitative), and when you want to mix the results. There are a few good books on this subject. For instance, a book by Creswell and Plano-Clark discusses mixed method designs.
Your field research sounds interesting. What kind of data will you collect to hopefully show that there is a difference between conjectures?