Science attempts to discover patterns in a reality that often seems chaotic. Even from the most ancient times, people have attempted to describe patterns in the world around them. Ancient peoples noted the changes of the season, changes in the phase of the moon, changes in the tide. They also noted that these things (and many others) changed in a regular pattern. In the sciences, things that change and have different values from time to time or from person to person are called variables.
A variable is a characteristic, attribute, or condition that has different values for different individuals.
Variables may be attributes that are different for different people, such as weight, gender, religious affiliation, political affiliation, and so forth. Variables can also be conditions in the environment that can affect the results of a study, such as the time of day when an experiment takes place.
When variables are measured, researchers often identify the variables by a letter, such as X. If two variables are used, then the researcher may denote the first variable as X and the second as Y. This shorthand is useful in describing the relationships between variables. A variable is sometimes referred to as a column of data because of the convention of placing information for each person in rows, which makes each column form a single variable. All the variables taken together form the data that we analyze in a research project.
A value that does not change from person to person is called a constant. The idea of constancy is closely related to the scientific concept of control, which we will discuss in more detail in a later section.
A constant is an attribute of a person or a condition that does not change from person to person but stays the same for every individual.
An attribute is a specific value of a variable. For example, the variable gender has two attributes: male and female. Attributes are commonly referred to as a level of the variable. It is important to note the difference between the variable and its value for a particular individual. For example, the variable gender can take on two different levels: Male and female.
Last Modified: 06/29/2018