Scientific control
Scientific control is a fundamental aspect of scientific experimentation that serves as a baseline for comparison against experimental groups. It involves maintaining certain conditions unchanged while varying others, allowing researchers to isolate the effects of specific variables. Without controls, it becomes challenging to determine whether observed changes in the experimental group are due to the interventions applied or other extraneous factors. For instance, in a study assessing a new drug, the experimental group receives the drug, while the control group does not; this setup helps clarify the drug's effects.
In an experiment, controls work alongside independent variables (factors that are manipulated), dependent variables (outcomes that are measured), and constants (factors that remain the same) to ensure validity and reliability. By ensuring that experimental and control groups share key traits, such as age or lifestyle, researchers can better understand the impact of the tested variables. The ultimate goal of employing scientific controls is to yield accurate and actionable results, guiding further research and decision-making.
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Scientific control
A scientific control is the component of a scientific experiment that is not altered so that the test subjects that are changed may later be compared to it. Scientists may employ as many controls as necessary in their experiments. Controls are vital to the success of experiments because they act as standards that indicate whether the results of the experiment are positive or negative.
In an experiment testing the potency of a certain drug, for instance, the people who receive the drug are called the experimental group, while the control, or control group, is the set of people who are not given the drug. After the experiment, the effects of the drug on the experimental group are compared to the condition of the control group to determine what exactly the drug did. Controls interact in different ways with the other components of an experiment—the independent variables, dependent variables, and constants—to produce results that answer the questions scientists proposed before executing the experiment.
Background
The scientific control is only one of the vital parts of an experiment. Controls, independent variables, dependent variables, and constants must all be present for an experiment to be considered scientifically valid. Each component plays a unique role and is important to the success of the experiment in its own way.
Independent variables are the parts of an experiment that are not changed by the other parts. They alter other parts of an experiment by being applied to them. Independent variables can be certain amounts of substances given to or applied to test subjects, unchanging forces such as speed or pressure, or the age of an individual being tested. These substances, forces, and ages are considered independent variables because they stay the same throughout the experiment.
Dependent variables, conversely, are the components of an experiment that are influenced by other factors. Dependent variables are the changes that scientists measure in the experiment. While an unchanging force may be the independent variable, the different objects upon which the force is acting are the dependent variables, since each object will react differently to the force.
Controls are the parts of an experiment that act as the basis of comparison to other experimental subjects. The experimental groups are altered due to the application of a force or other change, but controls are not altered in the same way. Scientists observe what becomes of all their test subjects to determine how the experimental groups have been affected by the changes they introduced.
Finally, constants are the factors that never change throughout an experiment. It is important that they remain the same because they could interfere with the results of the experiment if they were to change. For instance, a test subject's gender, height, and weight may all be constants in an experiment. If any of these changed during a scientific test, the dependent variable could change with them, thus making the conclusions of the experiment invalid.
Impact
Controls are necessary to producing accurate results in a scientific experiment because, without them, scientists would not be able to tell whether the changes they introduced to their experimental groups actually caused the results to occur. They need to include controls in their experiments—and not administer the same changes to them—so they can compare the effects of the changes on the experimental groups to the conditions of the controls after the experiment. This will determine whether it was in fact the administered changes that were responsible for influencing the experimental groups.
It is best for scientists conducting an experiment to ensure that their experimental groups and control groups are as alike as possible, or at least that they share some character traits or life experiences, such as being the same age or holding the same job. These commonalities will prove useful because the personal differences that led to the varied results between the experimental group and the control group will be highlighted.
For instance, scientists who want to test whether a weight loss medication works will first assemble two similar groups of people, an experimental group and a control group. The scientists will then administer the same dosage of the medication to each person in the experimental group, where the uniform dosage is the independent variable. The control group will not receive the medication at all. The scientists will then determine how much weight, if any, each person in the experimental group lost. The different amounts are the dependent variables. The constants in the experiment are the individuals' ages, heights, and weights. These factors must remain the same throughout the test, so the scientists can determine how the medication interacts with people who possess certain characteristics.
The importance of the control is apparent after the experiment has been completed. If the experimental group lost weight, but the control group did not, the scientists can conclude that the weight loss medication may be effective. This cannot be declared as a definite fact yet because other factors may also have influenced the individuals' weight loss. The scientists would then need to perform more experiments with the medication to prove whether it truly was responsible for the subjects' weight loss.
If both the experimental group and the control group lost weight, the scientists would need to determine what actions each group took to do so. If both groups ate healthier diets and exercised and lost similar amounts of weight, for example, the scientists might conclude that it was these actions, and not the drug, that caused the weight loss.
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