Which of the following is true about experimental studies? [Check all that apply.]â Experiments might have confounds.â Experiments might not be generalizable to external contexts.â Experiments look at natural correlations between variables instead of manipulating variables.â Experiments use manipulations to illustrate causality.â Experiments use random assignment to keep all other variables that are not of interest constant across conditions.â Results of experiments are on average for the sample population and are not universal rules.