Meta-analysis helps psychologists build knowledge
(Medical Xpress) -- When scientists want to know the answer to a question thats been studied a great deal, they conduct something called a meta-analysis, pooling data from multiple studies to arrive at one combined answer. Some people think this creates a chilling effect, shutting off further inquiry. But the authors of a new paper published in Perspectives in Psychological Science, a journal of the Association for Psychological Science, write that meta-analysis actually helps scientific fields develop.
There are many meta-analyses in psychology and medicine, areas where studies find often conflicting results. For example, some experiments might find that a particular drug decreases the risk of heart attack, while other experiments might find the drug doesnt have any particular effect. A meta-analysis takes the results from all published studies on the same question and combines them; its as if someone had done a single study with a much larger sample size.
The answers that a meta-analysis comes up with can guide the field. But it may also stop scientists from looking at questions related to whatever the meta-analysis was about. We started out asking the question, does it have a chilling effect? What happens after a meta-analysis? says Richard D. Arvey of the National University of Singapore, who co-wrote the article with graduate student Meow Lan Evelyn Chan. They looked at a particular area and found that researchers did continue to conduct studies after the meta-analysis was published.
Meta-analysis can be very useful, Arvey and Chan argue. Arvey gives an example from his own experience: He was an expert witness in an age discrimination case. The workers who thought they had been discriminated against had an expert witness who presented a study that found the kinds of things the company was accused of were because of age discrimination. But Arvey used a meta-analysis to show, he says, that The data this person had produced was an outlier, a very unusual result compared to all the other studies. He showed that this study did not represent what had been found by the field as a whole.
This method can also help guide scientists on what kinds of work to subsequently explore. Arvey is starting to study the neurological basis of leadership, and hes using meta-analysis to find out what personality characteristics are generally associated with leadership. I will start looking at specific measures of those traits in my own research, he says.
Just the fact that its possible to do meta-analyses in psychology shows that psychology is a fairly mature field, Arvey says. In order to do meta-analysis, you have to have enough scholars who have studied the phenomenon in the first place. Meta-analysis has helped psychology mature over the last 20 years, he says, helping scientists to develop paradigms for understanding human behavior and focus more on important questions.