|
Experimental Design A researcher can most convincingly identify cause-and-effect relationships by using an experimental design
In such a design, the researcher considers many possible factors that might cause or influence a particular condition or phenomenon
The research then attempts to control for all influential factors except those whose possible effects are the focus of investigation
Imagine that we have two groups of people
We take steps to make sure that these two groups are, on average, so similar that we can, for all intents and purposes, call them equivalent
For example, take two equivalent groups – give them a pretest to measure a particular characteristic in which we’re interested – then expose only one of the groups to a treatment or intervention of some sort that we think may have an effect on the characteristic we are studying – afterward, give both groups a posttest to measure the characteristic once again – if the characteristic changes in the treatment group and not in the other, then we can reasonably conclude that the treatment brought about the change we observed
We have used an experimental design since we have not only observed the situation but also manipulated it
|
|
