What is the purpose of conducting an experiment? How does an experimental design accomplish its purpose? What are the advantages and disadvantages of an experimental design in an educational study? What is more important in an experimental study, designing the study in order to make strong internal validity claims or strong external validity claims? Why? In an experiment, what is a control? What is the purpose of a control group? Of single or multiple comparison groups? What are confounds? Give an example of a design that has three confounds. Describe three ways to alter the design to address these confounds and explain the advantages and disadvantages of each. What does “cause” mean and why is it an important concept in research? How are correlation and causation related? You are a researcher interested in addressing the question: does smiling cause mood to rise (i.e., become more positive)? Sketch between-participants, within-participants, and matched-participants designs that address this question and discuss the advantages and disadvantages of each to yielding data that help you answer the question. Describe and discuss each design in 4-5 sentences.