As many as you need. You can't change more than one if you want accurate results.
to isolate and test single variables
Test variables are the factors that are intentionally changed or manipulated by the researcher in an experiment, whereas outcome variables are the factors that are measured and affected by the test variables. Test variables are the independent variables that are controlled by the researcher, while outcome variables are the dependent variables that change in response to the test variables. The relationship between the test variables and outcome variables is explored to determine the effect of the test variables on the outcome variables.
one
its called a fair test. :)
A controlled experiment allows the scientist to isolate and test a specific variable by keeping all other variables constant. This helps to determine the direct impact of the variable being tested on the outcome of the experiment. Controlled experiments are essential for establishing cause-and-effect relationships in scientific research.
an experiment to test a scientific hypothesis in which the variable component is controlled, not random, eg In an experiment that measures volume vs time to boiling, the volume, being the indirect variable, is measured.
When a scientific experiment is carried out in a controlled setting, all variables are kept the same except for the control variable. The control variable is something that is constant and unchanged in an experiment, and is held constant to test the relative impact of independent variables.
When a scientific experiment is carried out in a controlled setting, all variables are kept the same except for the control variable. The control variable is something that is constant and unchanged in an experiment, and is held constant to test the relative impact of independent variables.
When a scientific experiment is carried out in a controlled setting, all variables are kept the same except for the control variable. The control variable is something that is constant and unchanged in an experiment, and is held constant to test the relative impact of independent variables.
controlled experiment
all but 1...the 1 yu want tu test.
It means that except for the independent variable (the only factor that you change) you remain the other variables constant. To keep the control variables the same. Then this is a controlled experiment (fair test). Hope this helps :)