While performing an experiment, a positive control group is given a treatment that was used one time previously in another experiment. This time, however, the positive control does not give the expected result that you received last time. Which of the following is a likely case?
- The equipment or technique to measure the dependent variable is not working properly this time.
-The previous result you obtained was incorrect or flawed.
-A positive control is not useful for this experiment.
Am I right to assume that the answer is the first two choices?