Praxis Middle School Science (5442) Practice Test

Control is the standard reference point used for comparison in experiments. It stays under the same conditions as the experimental setups but without the factor being tested, providing a baseline to see what would happen without the treatment. This lets you isolate the effect of the variable you changed, so any observed differences are due to that variable rather than other factors. The independent variable is the factor you deliberately change to test its effect, and the dependent variable is what you measure in response. A law is a broad, well-supported statement about how part of the natural world behaves, not the reference point used for comparison in an experiment. For example, in testing a fertilizer’s effect on plant growth, you compare plants that receive no fertilizer (the control) with those that do, to see the fertilizer’s impact.