To get an accurate handle on the what the market's reaction will be, at least 25 qualified people should be interviewed for each significant product difference or formula. This will provide the basis for directional evaluation and changes in the prototype, or product positioning.
For smaller companies, selecting interviewees from local surroundings (e.g., local neighborhood for a single retail store) may be the most practical alternative. For companies doing business in a larger region or nationally, attempts should be made to obtain as representative a sample of interviewees as possible throughout the company's marketing area.
The problem with qualitative research is that your confidence level, that the results are indicative of the general population or key target group trends, will be somewhat low. At this statistically low level of predictability, you should be looking for broad general indicators or trends to guide the next steps.
If 100 percent of qualitative test respondents like your new product, perhaps it has significant merit. On the other hand, perhaps one "loudmouth" in the focus group liked it, and everyone else was afraid to voice a contrary opinion.
The questionnaire for qualitative research could include:
- demographic information (what is their age, sex, occupation, home locale, income range, etc.)
- confirmation that they use the product or service you're testing
- which brands are used or purchased
- how often brands are purchased
- why they like different brands
- what is disliked about different brands
- discussion of different product attributes
- discussion of the importance of various product attributes
- evaluation of product prototype
Ideally, your test results should be confirmed by quantitative research or a real-market field test. In qualitative testing, small differences between your product and competitive products may be meaningless.