Scatterlots

A scatterplot groups points on a two-dimensional graph in which each dot represents a single person’s data. Any two variables can be plotted on a scatterplot. In this example, a research study in a newspaper article claims that since there is a positive correlation between taking vitamins and crime rates, vitamins cause crime. While scatterplots imply causation and people often use them to display a relationship, they cannot be used to prove a cause-and-effect relationship. The only research design that allows researchers to infer causation is experimental designs. Therefore, in order to prove (or disprove) a causal relationship between vitamins and crime rates, an experiment must be designed.
One of the key principles in statistics is “correlation does not equal causation.” Any two independent variables could happen to be correlated, but that does not show a cause-and-effect relationship between the two variables. The two variables researched through a …show more content…
Participants for this study would be randomly selected then randomly sorted into two groups: experimental group and control group. The control group would not take vitamins. The experimental group would take vitamins daily. In this study, the independent variable would be taking vitamins. The dependent variable would be crime rates and would measure whether the manipulation has an effect. For this experiment, the groups would have to be reasonably large in order to increase reliability.
In the correlational design study in the newspaper article, causation cannot be inferred because of the key statistical principle “correlation does not equal causation.” In order to determine causation, a double-blind experiment must be conducted. The results of the double-blind experiment would be the true indicator of any cause-and-effect relationship between taking vitamins and crime