Quantitative Research Correlational Studies and Experiment Design

Correlation

Positive vs. Negative Correlations Positive Correlation Negative Correlation The more sexual content teens see on TV, the more likely they are to have sex (Collins et al., 2004). The more young children watch TV, the less they read (Kaiser, 2003).

Correlation vs. Causation

Example 1

Example 2

Example 3

Correlation CANNOT prove causation! It can only suggest a possibility. Get it? Correlation CANNOT prove causation! It can only suggest a possibility.

Tries to establish a cause and effect relationship. Experiment Design Tries to establish a cause and effect relationship.

Experiment Features Aim Independent Variable Dependent Variable Sample Procedure Findings Conclusion

Aim Purpose of the experiment. What is being investigated. What was the aim of the heart rate experiment?

Variables

Independent vs. Dependent Independent Variable Dependent Variable Experimenter manipulates Assumed to have a direct affect on the dependent variable Measures effect of independent variable

Application In the heart rate experiment, what were the independent and dependent variables?

Sample and Target Population

Application Describe the characteristics of the sample in the heart rate experiment (e.g. how many participants, average age, how many girls/boys) What was the target population of the heart rate experiment?

Procedure

Findings and Conclusions The results of the study What the research actually found What the findings suggest or mean

Application Outline the procedure of the heart rate experiment What were the findings? What conclusion(s) can you draw from the experiment?