Research methods can be divided into two main groups: generative and evaluative.

Generative research methods are used to gather knowledge: discover new insights and ideas about business, users and their needs. These methods are typically conducted early in the design process, before a product or service has been developed, in order to inform the design and development of the product or service. Some examples of generative research methods include user interviews, card sorting or ethnographic research.

Evaluative research methods are used to test and evaluate specific design solutions or prototypes. These methods are typically conducted later in the design process after a product or service has been developed in order to identify areas for improvement. Some examples of evaluative research methods include usability testing, tree testing, or A/B testing.

Methods can be split among the quant-qual axis as well.

Quantitative research methods require a bigger pool of participants (30+) and offer you reliable results.

Qualitative research methods require less participants and go into more depth. You’ll learn more about the why’s of people's behavior. But generalizing your findings is a tricky thing. Your sample will be 5-10 people, so you need to tread lightly when using those insights.

For the purposes of this Handbook, we’ll stick with the qual-quant split. To add some confusion to the mix, in most of the cases — the split is not clear. For example, you can add a qualitative question to find out why participants provided some of the quantitative answers.