How to do True Experimental Design
How to do True Experimental Design?
Experiments are the classic way to conduct research in almost any field of study. But do you know how true experiments really work? This lesson explains the details of experimental design, such as different types of samples, control groups and independent vs. dependent variables.
Scientists in almost every field of study use experiments to answer research questions. Imagine you are a psychologist, and you want to investigate whether caffeine has an effect on student behaviors and performance in the classroom. How would you go about finding out the answer to this question? The answer is that you would do an experiment. This lesson covers all of the different aspects of an experiment you would want to consider.
Independent and Dependent Variables
The first thing any experimenter needs to decide is what variables you are studying. Let's imagine your hypothesis is that when students in school consume caffeine, their performance on tests is affected. You might hypothesize that caffeine increases test performance because it causes the students to be less sleepy and more focused, or you might hypothesize that caffeine decreases test performance because it makes the students jumpy and hyper. Either way, you have two variables involved in this study.
The independent variable in an experiment is the variable that you control as the experimenter and the one that creates two or more groups in the study. In order to study caffeine, you might give half of the students a caffeinated drink and the other half of the students simply get water. The difference between the two groups is whether they have caffeine or not. So, the independent variable is the variable that you, as the experimenter, have manipulated.