yes all experiments need to have a control
All properly-designed experiments should have some sort of control.
Yes, because if there is no control group, the results of the experiment are meaningless. If i had two plants, one I used miracle-grow on and the other I never watered, I wouldn't know if either of my variations (not watering and using miracle-grow) were meaningful without having another plant which lived a normal life (with adequate water) to compare it to.
To have something to compare to that was exposed to all the same conditions, except the single variable condition being tested.
The experimental control provides a base-line result or set of results, from which you can compare the variables' effects against. It's designed to minimize the effects of variables (other than the single independent variable). Control groups are often included in medical or psychological experiments so that the results of an experiment are considered reliable and trustworthy.Example:A mystery-drug cure is being tested. One group of patients is given the drug and the other group is not. The group without the drug will be subject to all the same conditions that the other group are under, thereby seeking to eliminate any unforeseen effecting environmental factors. This makes it possible to compare, and therefore measure, the impact any drug would have.
control group
All properly-designed experiments should have some sort of control.
Yes, because if there is no control group, the results of the experiment are meaningless. If i had two plants, one I used miracle-grow on and the other I never watered, I wouldn't know if either of my variations (not watering and using miracle-grow) were meaningful without having another plant which lived a normal life (with adequate water) to compare it to.
To have something to compare to that was exposed to all the same conditions, except the single variable condition being tested.
it is difficult to control all variables except the one being tested
The experimental control provides a base-line result or set of results, from which you can compare the variables' effects against. It's designed to minimize the effects of variables (other than the single independent variable). Control groups are often included in medical or psychological experiments so that the results of an experiment are considered reliable and trustworthy.Example:A mystery-drug cure is being tested. One group of patients is given the drug and the other group is not. The group without the drug will be subject to all the same conditions that the other group are under, thereby seeking to eliminate any unforeseen effecting environmental factors. This makes it possible to compare, and therefore measure, the impact any drug would have.
we are all scientists. we all use experiments
Sure. "After all the subjects in the control group take the normal pill we'll give the test group subjects the placebo without telling them.
The group that is not altered in an experiment is the control group, because all conditions are kept the same.
it is difficult to control all variables except the one being tested
it is difficult to control all variables except the one being tested
Control groups are important because if you didn't have them you could not tell if the test is effect or not. For example. if testing a new medication on mice and you have three different levels (doses) and all of the mice get better, you still can not say that the decreased symptoms is due to the medication because there is no control group. The control group in this particular example would measure the effects of time. Without it you can not tell if the mice got better due to the medication, or if time alone cured the mice. Does this help?
Experiments are typically conducted in laboratory settings, where researchers have control over variables and can monitor and manipulate conditions. Other common locations include field studies, where experiments are conducted in real-world environments outside of a controlled lab setting.