Students understand that:

• A statistical question is one that can be answered by collecting data and where there will be variability in that data.
• An experiment is a controlled study in which the researcher attempts to understand cause-and-effect relationships. Based on the analysis, the researcher draws a conclusion about whether the treatment ( independent variable ) had a causal effect on the dependent variable.
• Statistical surveys are collections of information about items in a population and may be grouped into numerical and categorical types.