== Questions about multivariate analyses ==
1. [[FAQ/heterogeneity| What is heterogeneity of variance in SPSS Probit and Logit procedures?]]
1. [[FAQ/SobelTest|How do I test whether one independent variable has an influence on a dependent variable other than via the mediation of a second independent variable? (Sobel Test)]]
1. [[FAQ/Collinearity|What is collinearity in multiple regression, and what do I do about it?]]
1. [[FAQ/condnoR| How do I find the condition number of a matrix using R?]]
1. [[FAQ/RatCaseVar|Is there an optimal ratio of cases to predictor variables I should have before performing a multivariate analysis or any guide as to total sample size?]]
1. [[FAQ/patternMatrix| Which matrix of loadings do I use doing a principal components extraction or non-PC analysis with a direct oblimin rotation when doing a factor analysis?]]
1. [[http://pareonline.net/getvn.asp?v=14&n=20| A guide to the pros and cons of choosing a method for producing factor scores from a factor analysis]]
1. [[FAQ/thresholds| What thresholds should I use for factor loading cut-offs?]]
1. [[FAQ/congruenceC| How do I compare a pair of factor loadings?]]
1. [[FAQ/compare| What is the difference between principal components analysis, principal axis analysis and other factor extraction methods?]]
1. [[FAQ/NoFactors| How many factors should I retain in a factor analysis?]]
1. [[FAQ/Cronbach| A note on Cronbach's Alpha.]]
1. [[FAQ/PlusFac| How do I interpret variables which load on more than one factor?]]
1. [[FAQ/mds| What is multidimensional scaling and how do I do it?]]
1. [[FAQ/cancorr| What is canonical correlation and where can I use it?]]
1. [[FAQ/MANOVA|When should I use a Multivariate Analysis of Variance (MANOVA)?]]
1. [[FAQ/infmles|Why are the standard errors so large in logistic regression?]]
1. [[FAQ/logrrsq|How do I choose between different logistic regression models?]]
1. [[FAQ/cluster|How do I perform a cluster analysis in R?]]
1. [[FAQ/threshold|Which discriminant analysis should I use to obtain thresholds to indicate levels of abnormality using a single variable?]]
1. [[FAQ/structure|How do I assess the importance of variables in a Normal Discriminant analysis?]]
1. [[FAQ/criteria|Can you recommend any two group discriminant diagnostics?]]
1. [[FAQ/NDcasestat|Which output criteria should I use when using the casewise results option with the Normal discriminant method in SPSS?]]
1. [[FAQ/roc|How do I plot and interpret a ROC curve in assessing strength in two group prediction?]]
1. [[FAQ/missing|How do I handle missing data in multivariate analyses in SPSS?]]
1. [[FAQ/locf|Using SPSS syntax to impute last observation carried forward (LOCF) for missing values in SPSS]]
1. [[FAQ/cc|How do I find complete cases in SPSS and R?]]
1. [[FAQ/lag|How can I detect identical (duplicate) cases in SPSS without having an ID number?]]
1. [[FAQ/euclid|What is Euclidean distance and how do I compute it?]]
1. [[FAQ/mahal|How do I detect multivariate outliers?]]
1. [[FAQ/sem|Structural equation modelling in R]]
1. [[FAQ/texts| Can you recommend any statistical textbooks?]]
1. [[FAQ/mvnormc| How do I check for multivariate normality?]]
1. [[FAQ/uneqcovs|What do I do if I have unequal group covariance matrices when doing a MANOVA?]]