Types of usability studies

In addition to the usability testing methodologies, there are also different types of studies that can be executed using the various methodologies:

• Formative (exploratory) versus summative (assessment)
• Qualitative versus quantitative
• Longitudinal studies versus single session
• Comparative studies versus single product under testing

These types are not mutually exclusive: For example, a comparative study can also be a formative study and a longitudinal study can also be a qualitative study.