A control variable, also known as a scientific constant, is an experimental element that is held constant and unchanged throughout the course of an investigation. Control variables are not of primary interest to the experimenter, but they are important because they could strongly influence experimental results if they were not held constant during the experiment. In other words, control variables are anything that is held constant or limited in a research study, and they are not of interest to the studys objectives, but are controlled because they could influence the outcomes.
Control variables can be controlled directly by holding them constant throughout a study, such as controlling the room temperature in an experiment, or they can be controlled indirectly through methods like randomization or statistical control, such as accounting for participant characteristics like age in statistical tests. Scientists can control variables using several methods, such as using standardized procedures and processes for all subjects to reduce other sources of variation.
In summary, a control variable is an element that is kept the same throughout an experiment in order to assess the relationship between multiple variables, and it is not of primary concern in the experiment.
