15.7 What to watch out for

• Number of factors should be chosen with care. Check default options.
• There should be at least two variables with non-zero weights per factor
• If the factors are to be correlated, try oblique factor analysis
• Results usually are evaluated by reasonableness to investigator rather than by formal tests
• Motivate theory, not replace it.
• Missing data - factors will only be created using available data.