What is the difference between control group and constants




















Randomization is necessary to deal with individual differences. Replicate - Replicates are individuals or groups that are exposed to the same conditions in an experiment, including the same level of the independent variable. It is necessary to have replicates to prove a relationship between independent and dependent variables.

Sampling - The sample is the portion of a population examined in your study. If the population is divided into sub-groups then it is important to have the correct relative ratio of the sub-groups in the sample. Encyclopedia of Research Design. SAGE Publications, The Practice of Social Research. Cengage Learning Publishers, Newnes Publishers, User assumes all risk of use, damage, or injury.

You agree that we have no liability for any damages. What is a Constant? Other examples include freezing and boiling points of water, the speed of light, What is Controls?

Other examples include time, pressure and temperature. Similarities between Constant Vs. Control Both are important in experiments as they determine the outcome Differences between Constant and Control Variation A constant variable does not change. Primary interest While the constant is the variable of primary interest, the control is not; hence its influence can be controlled or eliminated. This is because the focus is on how a plant reacts to different forms of light and not how it reacts to different temperatures.

Thus, the amount of temperature in this experiment is a control variable as it is an element that needs to be controlled. Similarly, the person experimenting also needs to be careful with the amount of water he is giving to each plant.

This is because, if by any chance one of the plant is given more water than the other plants, it would not be possible to comprehend the reason behind the growth of that plant. One would fail to know if the reason behind the growth of that plant was a form of light or excess water.

In a science experiment, a control variable is not of any primary importance. Rather it acts a third factor. But it is still important for an experiment. This is because it helps in comparing other variables that may have contributed to a particular outcome of the experiment as all variables pertinent to the experiment are kept the same or under control by the person experimenting.

While graphing an experiment, the independent variable is represented by the x-axis while the y-axis represents the dependent variable. But the controlled variables are not depicted on a graph as they are not supposed to change. But they can be depicted on a graph to make sure that all other variables except independent and dependent variables should not change.

For example; after plotting the growth of plants in comparison to the lights received on a graph, one can also check if all the plants received the same amount of temperature or water or not. If any variation is found, one needs to re-check the set up of their experiment. In some cases, a property can be considered constant for the purposes of an experiment even though it technically could change under certain circumstances.

The boiling point of water changes with altitude and acceleration due to gravity decreases with distance from the earth, but for experiments in one location these can also be considered constants. The independent variable in an experiment is the variable whose value the scientist systematically changes in order to see what effect the changes have.

A well-designed experiment has only one independent variable in order to maintain a fair test. If the experimenter were to change two or more variables, it would be harder to explain what caused the changes in the experimental results. For example, someone trying to find how quickly water boils could alter the volume of water or the heating temperature, but not both.



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