1. applied research observational evidence 2. basic research the experimental factor that changes in response to a change in the independent variable 3. control research that results in a product that can be sold for profit 4. dependent variable a proposed explanation for a scientific problem that itself can be tested by experimentation 5. empirical evidence a quantity in an experiment that remains unchanged or constant 6. hypothesis research that expands knowledge in a particular area 7. independent variable the experimental factor that is changed by the scientist