We use questionnaires to study recognition or to measure psychological indexes. In this site, CVM (a tool of Environmental Economics ) , Environmental Psychology , Risk Cognition , etc use questionnaires as a main tool.
When we take good questionnaire, we get good data. Then we can use Statistics and Multi-Variable Analysis . Tools for physical indexes are also used to psychological indexes basically.
Some process of questionnaire lead answers. Some effects are known.
"SD" stands for "Semantic Differential". This method measures the image of words. For example, using words "bright" and "dark", and 7 levels. If you think, a little dark then you answer "6". Or if you think, middle of them then you answer "4"
Design of Experiments is used in Conjoint Analysis for the field of Marketing .
In general experiments, sets of levels are designed and experimented. In Conjoint Analysis, levels are values and quality. By questionnaire, we get the points of the sets of levels as "Y" data.
NEXT Scaling Method