Comparative Experiments involve testing two variables by designing an experiment.  It contains a testable hypothesis, at least one independent (manipulated) variable, one dependent (responding) variables and a control group.  Comparative experiments are usually designed to test the relationships between independent and dependent variable.  The comparative experiment can be designed to collect data on different organisms/objects/features/events or collect data under different conditions (e.g., time of the year, temperature, pH, location) to test the hypothesis. Data can be collected both quantitatively and/or qualitatively to draw conclusions and to support or to reject the hypothesis.