Q: What would be the right sampling technique for a research involving multiple case studies?

You have already chosen the companies. So, we assume the question is about choosing a sample of employees from each of them. First off, this is a case study, which itself implies that the findings are not expected to be generalizable across the board but are indicative, which, in turn, allows some leeway in choosing the samples.

That said, much depends on the size of the company and the numbers you are prepared to handle. If the companies are small, perhaps you can eliminate sampling altogether and interview everyone? If this is not feasible, you need to decide on what category of employees to choose: the management level, for example, or the number of years of serving the company. If the company has multiple locations, you may want to ensure that all locations are represented.

These considerations call for stratified sampling, and the numbers should be drawn in proportion to the size of each strata. For instance, if one location has many employees and another has only a few, you may choose the number of employees in proportion. The topic also implies a qualitative rather than a quantitative approach, which again means that a rigorous sampling exercise may not be required.

Given the limited information on your proposed research, any (more) specific recommendations will be out of place at best and misleading at worst. However, we hope you will think along the lines suggested to come up with the most suitable sampling technique. All the best!

For more insights on some of the key points discussed above, you may find the following resources useful:

• Which method can be used to obtain quantified data by comparing three groups within an organization though with a different sample size in each group?
• What kind of research method should I use for my thesis: qualitative or quantitative?
• Types of qualitative research methods

[With inputs from Yateendra Joshi]