Psychology / Statistics / Data Analysis / Simulation / Correlation / Maximum Likelihood / EM algorithm / Random-Effects Models / Simulation Study / Covariance Matrix / Correlation coefficient / Multivariate Normal Distribution / Likelihood Function / Confidence Interval / Maximum Likelihood Method / maximum likelihood estimate / Maximum Likelihood / EM algorithm / Random-Effects Models / Simulation Study / Covariance Matrix / Correlation coefficient / Multivariate Normal Distribution / Likelihood Function / Confidence Interval / Maximum Likelihood Method / maximum likelihood estimate