I am currently working on my thesis and I am working on conducting a user research on the chatbot experience with real users. Currently, I'm going to test three different chatbot prototypes to test:
(1) For each prototype, I will find around 5-7 users to test it
(2) To test each prototype, I will first interview them (to know their chatbot usage, their background, etc.), then the usability tests (by giving them tasks), and finally I want to use metrics to measure the quality of the prototype.
(3) I wonder if anyone recommends measures to measure the usability of a chatbot app? I was currently planning to use the SUS questionnaire, which I found a few theses using to assess the chatbot, but I don't know if it works with a small number of samples (5 users).
Does anyone recommend different approaches?