All researchers know, qualitative interview is for in-depth information, it helps us understand why consumer like a brand, and quantitative interview tells us how many of consumers like a brand. 　     For most of our interviews, we usually interview our respondents once, or qualitative method or quantitative method. For some special purpose, we may want to firstly understand consumers' usage behavior, then we still want to know why should they have these behavior. So Gang survey is the best choice for this purpose.   Gang survey has usually been set into two stages, qualitative interview and quantitative interview. It doesn't matter who does first, the two methods will match each other. Product Test for Micro-wave Oven 　 　 Microwave manufacturer wants to launch new products, they want to test their products which are best products in other markets. Their purpose is to choose the highest accepted product, and will launched into China market. 　 　 7 ovens had been set on the test table in the rest room. All respondents can watch ovens and even use it to cook when they are wait for starting interview. 10 minutes later, they were asked to fill in questionnaire based on their observation in the rest room. In this questionnaire, they choose the highest accepted product. Then all respondents were leading into another room with a table in the middle and 20 chairs around this table. Moderator collect all questionnaire and discuss with respondents based their answer one by one. Other respondents can express their different opinions.