Classification of conjoint analysis
We are often asked what types of conjoint analysis exist and which ones we offer on Conjoint.ly. Here is an opinionated classification of conjoint analysis that helps you understand what some experts are talking about.
By response type
- Rating-based conjoint: Respondents are asked to rate the product alternatives they are shown. This can be on a scale of 0 to 100. Respondents may be required to allocate scores so that the scores sum to a certain number (e.g., all scores in each question must add up to 100).
- Best-worst conjoint: Respondents are asked to indicate which option is best and which option is the worst among three or more alternatives in each question.
- Ranking-based conjoint: Respondents are asked to rank alternatives from best to worst. It is similar to best-worst scaling, but respondents also need to allocate rankings to the intermediate alternatives.
- Choice-based conjoint (CBC): Respondents are asked to choose which option they will buy or otherwise choose. This is the most theoretically sound, practical, and popular method of conjoint analysis. Conjoint.ly proudly offers only CBC because other response types are known to be inferior for practical market research.
By questioning approach
- Standard conjoint: In standard conjoint, the questionnaires are developed before they are sent to participants. They are carefully designed by using sophisticated algorithms to ensure best quality analytics, including segmentation analysis. Conjoint.ly offers standard conjoint.
- Adaptive conjoint (ACA; when it is choice-based, it is also called ACBC): In adaptive conjoint, the questionnaire is constructed during the interview. It “adapts” to participants’ responses to optimise a certain parameter (such as minimising confidence intervals for certain partworth utilities). It is a more complicated technique, which may generate problems with certain types of analysis, such as in segmentation. It does have certain valid applications (such as reduction of the required sample size in very complex studies) – please reach out to us if you require assistance with this.
By type of design
- Generic conjoint: In generic conjoint, the researcher is examining a single brand or an undifferentiated product category, where all products essentially have the same attributes and levels.
- Brand-specific (alternative-specific conjoint, alternative-specific design, ASD): In generic conjoint, the researcher is examining multiple brands in a differentiated product category, where different brands have different levels applicable to them. These “alternatives” are not necessarily brands. For example, they can be modes of transport (such as “walking”, “taxi”, “bus”) and the different levels applicable to them will necessarily differ (for example, cost of “walking” is usually free, the possible costs of “taxi” will typically be higher than the costs of “bus”).
Conjoint.ly offers both types of designs.
By whether all attributes are shown in every question
- Full profile: In full-profile studies, all attributes are shown in every choice set. It is recommended that the number of attributes is limited to about six because it is hard for respondents to digest more information.
- Partial profile: In partial-profile studies, only a subset of attributes is shown in each choice set. For example, the study may include 12 attributes, but only 6 will be shown in each question. This is a useful technique when you need to select different features for your product.
- Two-stage conjoint (also called dual response): In two-stage studies, respondents are first given a choice of products they would buy, and after making a selection they are asked if they would consider buying this alternative at all. This questioning technique leads to a slightly more realistic estimate of respondents’ preference not to buy an item.
- Availability design (cross-effects): If there are reasons to believe that the presence of one brand affects people’s preferences for other brands, then there is an “availability effect”. Special considerations are required in the design of the questionnaire and analysis of the data. In practice, only in rare cases researchers observe availability effects.
- Interaction effects: If there are reasons to believe that preference for a product is not simply the sum of preferences for its levels, but rather that certain levels have different likeability when combined with each other, then there may be an “interaction effect”. For example, furniture buyers may prefer lower prices and more exotic types of wood, but when a very low price is combined with an exotic wood material, they may in fact dislike the product (for example, because the combination is perceived as too “cheap” or incongruent). However, research suggests that in the vast majority of studies, interaction effects are minimal.
Our team at Conjoint.ly can help you with any type of customised conjoint analysis, even if it is not offered as part of our online tool. If you require a two-stage, partial profile, or any other type conjoint, please do get in touch with us.