In order to point out the best utility of a product (or a service), marketers need to clearly understand and measure the preference of the consumers. Among numerous marketing analysis techniques, the conjoint analysis is one of the popular tools for market research. One of the issues with this tool is the lack of feedback for the respondents. This paper proposes personal stepwise conjoint analysis based on an interactive Web-questionnaire allowing respondents to receive a diagnosis of their evaluation and giving the possibility to reconsider their evaluation. To validate our proposal, experimentation with forty-two respondents is also demonstrated. Experimental results, potential modifications and improvements are detailed in this paper.