Survey research and design in psychology/Tutorials/Psychometrics/General steps

General steps
Recommended psychometric instrument development steps emphasised in this tutorial are:
 * 1) Check and prepare the data
 * 2) Reverse code (if necessary) so that all variables are scored in the same direction
 * 3) Examine the univariate properties (e.g., histogram, mean, standard deviation, skewness, and kurtosis)
 * 4) Examine the bivariate properties (e.g., scatterplots and correlations) to help understand the data.
 * 5) Exploratory factor analysis
 * 6) Decide on a purpose and ask a research question (e.g., what are the underlying dimensions of X?)
 * 7) Examine assumptions (sample size, linear relations, and factorability)
 * 8) Choose method of:
 * 9) * extraction (PC/PAF) and
 * 10) * rotation (Orthogonal (Varimax) / Oblique (Oblimin))
 * 11) Determine the number of factors
 * 12) Name and describe each factor
 * 13) Identify which items belong to each factor, drop problematic items as necessary, and repeat analysis
 * 14) Analyse internal consistency for each factor
 * 15) Examine correlations amongst the factors
 * 16) Compute composite scores (if needed)
 * 17) Check factor structure across sub-groups