Why is a control set-up being done in conducting an experiment? Give example.
A control set-up is done in conducting an experiment to serve as a reference point for comparison. It allows scientists or researchers to isolate the effect of the independent variable (the factor being tested) on the dependent variable (the factor being measured). By having a control group or condition where the independent variable is absent or at a baseline level, experimenters can determine if any changes or observations are due to the independent variable or some other factors.
Here's an example to illustrate the importance of a control set-up:
Let's say a scientist wants to test the effectiveness of a new drug in reducing headaches. To conduct this experiment, the scientist would divide a group of individuals with headaches into two groups: the experimental group and the control group.
In the experimental group, individuals would be given the new drug to treat their headaches. In the control group, individuals would be given a placebo (a harmless substance with no therapeutic effect). Both groups would be observed and the severity or frequency of their headaches would be measured over a specified period of time.
By comparing the two groups, the scientist can determine if any observed changes in the experimental group are a result of the drug or if they occur naturally (due to other factors like time or the placebo effect). The control group provides a baseline to measure the effectiveness of the new drug and ensures that any differences observed are due to the drug itself and not other variables.
In summary, a control set-up in this experiment allows for a reliable assessment of the impact of the independent variable (the new drug) on the dependent variable (headache reduction) by establishing a reference point for comparison.