You should only change one at a time. By doing this, you can isolate individual problems and/or improve an experiment. If you do more than one and something is wrong, you dont know which factor created the problem.
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You only change 1 iv ( independent variable in a experiment ) HOPE IT HELPS :)
You have to change the core
Among other factors, the answer will depend on: the variability of the response (dependent) variable, the cost (disbenefit) of making the wrong decision based on the outcome, the cost of conducting the experiment repeatedly.
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In a controlled experiment only 1 variable is being tested.
Infinitely many. The answer depends onhow many times the experiment is repeated.Infinitely many. The answer depends onhow many times the experiment is repeated.Infinitely many. The answer depends onhow many times the experiment is repeated.Infinitely many. The answer depends onhow many times the experiment is repeated.
If it is the same experiment attached to link, you would need only 1 trial each unless you want to retry if there is more grain or shape distribution. There is no requirement for how many time in repeating experiment since it is observation experiment not measuring experiment.
The control is an object where you change nothing; you compare it to the thing that you test.
Repeat the procedure at least twice, preferably 3 times. Only keep 1 thing in your experiment the same. Change the materials or anything you are using.
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In general yes. But it really depends on the experiment. If you want to know if it hurts to punch a wall, you don't need an independent variable (unless you want to compare the magnitudes of the pain). But for school experiments, most of the time, if not all of the time. Yes.