How to specify the participant group size for usability studies: a practitioner's guide
Ritch Macefield · Journal of Usability Studies archive · 2009
Using secondary literature, this article helps practitioners to specify the participant group size for a usability study. It is also designed to help practitioners understand and articulate the basis, risks, and implications associated with any specification. It is designed to be accessible to the typical practitioner and covers those study scenarios that are common in commercial contexts.