what is statistical analysis of predictor variables do covariates have to be collected at two different time points? do covariate change between covariate what is a two time period analysis can predictor variable change affect outcome what is the relationship between outcome and predictor? how do you use the relationship between variables? what are the covariates? what is expected when the predicting variable is collected by the same time point? what is normal distribution of outcome measures why are covariates not related to predictors why is the normally distributed outcome measured at two time points? when can predictors of change be applied in statistics what is the difference between sex and predictor of change why does a covariate change between two time points why don't two time points mean an outcome can covariate variables and predictors change what is the relationship between predictor variables and covariates predicting the outcome of a study at different time points which covariate is normally distributed and which is normally distributed? why would the predictor variables change in an outcome how to analyse predictors of change in statistics