You’ve all come across headlines like, “Eat dessert for breakfast to lose weight” or “Facebook can raise your self-esteem” or “Why we lie”. Your first question may be “How big was the sample? Was it representative of the whole population?” or “Was the sample random?” By now, I hope you’ve learned that there is much more to a good study than the sample size, not every problem in a study is called a confound and understand the difference between random assignment and random sampling.
My goal in this course is for you to learn a systematic way of evaluating research using the 4 big validities (Cook & Campbell, 1979): External Validity, Internal Validity, Construct Validity and Statistical Validity. You can ask the following 4 questions about any study you read:
Can we generalize the results? (External Validity),
Was it an experiment and if so, was it a good one? (Internal Validity),
How well did they operationalize that variable (Construct Validity) and
Did they have enough people to detect an effect, how big was the effect and is it significant? (Statistical Validity)
For your final paper, you are required to read and critique 2 news articles with provocative headlines using the 4 components of Validity (External, Internal, Construct and Statistical). You may choose any of the news articles from this site: www.psychologicalscience.org/MembersInTheNews.
Sample Solution
