When conducting a good statistical study, it is important that your ____ is representative of the population. Observational studies do not allow researchers to draw cause-and-effect conclusions because the studies do not control for (i.e. variables that are not included in the study as explanatory variables but may influence the relationship between variables in the study).Observational studies do not allow researchers to draw cause-and-effect conclusions because the studies do not control for (i.e. variables that are not included in the study as explanatory variables but may influence the relationship between variables in the study)