Contents
What is the difference between an experimental group and a control group?
An experimental group is the group that receives an experimental procedure or a test sample. A single experiment may include multiple experimental groups, which may all be compared against the control group.
Is the mean of the experiment the same as the control?
The hypothesis you are trying to test is that the mean of the experiment group μ E is the same mean as the mean of the control μ C. Essentially you are testing if μ E − μ C = 0.
What is the true variance of the experiment group?
Suppose that the true variance (not sample variance) of the experiment group is σ E 2 and that you have a sample size n E. Likewise the control group variance and sample size is σ C 2 and n C. From your samples you will be examining X E ¯ − X C ¯ to test the hypothesis μ E − μ C = 0.
Which is the independent variable in an experiment?
The independent variable is “controlled” or held constant in the control group. A single experiment may include multiple experimental groups, which may all be compared against the control group. The purpose of having a control is to rule out other factors which may influence the results of an experiment.
How to compare 2 different groups ( control vs treatment )?
Separate one-way randomized ANOVA (as follow-up tests) for each time point to assess at what time point these mean values became significantly different between treatments. 3. Another follow up test, separate one way repeated measures ANOVA’s for each treatment to get value for significance within treatments.
Why is it important to have control groups?
Importance of control groups Control groups help ensure the internal validity of your research. You might see a difference over time in your dependent variable in your treatment group. However, without a control group, it is difficult to know whether the change has arisen from the treatment.
How to compare two groups for statistical differences?
In the final part of the article, a test selection algorithm will be proposed, based on a proper statistical decision-tree for the statistical comparison of one, two or more groups, for the purpose of demonstrating the practical application of the fundamental concepts.