R-type versus Q-type factor analysis

Both types of factor analysis utilize a correlation matrix as the basic data input. 

• With R-type factor analysis, the researcher would use a traditional correlation matrix (correlations among variables) as input.
• But the researcher could also elect to derive the correlation matrix from the correlations between the individual respondents. In this Q-type factor analysis, the results would be a factor matrix that would identify similar individuals
• From the results of a Q factor analysis, we could identify groups or clusters of individuals that demonstrate a similar pattern on the variables included in the analysis

A logical question at this point would be: How does Q-type factor analysis differ from cluster analysis, because both approaches compare the pattern of responses across a number of variables and place the respondents in groups? 

• The answer is that Q-type factor analysis is based on the intercorrelations between the respondents, whereas cluster analysis forms groupings based on a distance-based similarity measure between the respondents’ scores on the variables being analyzed.

Nguồn:

• Hair, J. F. (2009). Multivariate data analysis.