Sources for data collection : Case Studies

Advantages:  
-It can be used to more easily study a complex theme, by focussing on one example to obtain an initial understanding on a more basic applied level.
- They are good for obtaining finer details to directly illustrate a specific point 




Disadvantages:
-Generalising trends and assuming patterns from one case study can be applied elsewhere should be done with caution as they may not always be valid.
-They can be very easily subject to bias (including the bias of choosing what to use as the case study itself!)
-Relevant case studies may be hard to find if you are looking into a particularly uncommon area
-Case studies can often lead you off on tangents, and you could find you have too many fine details on one small area which is not hugely important within the whole project.