Question

V. Experimental Research   

In an experiment, a researcher manipulates one variable – the independent variable – to see how it affects at least one

other variable – the dependent variable.

Explain this statement by describing the famous experiment by Pennebaker that began the chapter – the effect of emotional expressiveness on health. This takes multiple sentences.

*You don’t need to explain each of the 6 steps of constructing an experiment in the text – just the items below.

Answer 1

The two main variables in an experiment are the independent and dependent variable. An independent variable is the variable that is changed or controlled in a scientific experiment to test the effects on the dependent variable. If the independent variable is changed, then an effect is seen in the dependent variable. In his research, Pennebaker's independent variable was writing about traumatic events and the dependent variable was visits to the healthcare center. He manipulated the independent variable by assigning healthy undergraduates to one of four groups: three groups wrote about personally traumatic life events for 15 minutes for 4 consecutive nights while the fourth group wrote about trivial topics for the same time. To measure the dependent variable, he tracked the undergraduate participants’ visits to the university health center over the next six months.