Types of Variables in Research

What is an independent variable?

• A variable that reflects the outcome of the research

• A variable that cannot be observed in an experiment

• A variable that changes the relationship between dependent and independent variables

• A variable that other variables in the experiment cannot change

Tags

NGSS.MS-PS2-2

What is a dependent variable?

• A variable that reflects the outcome of the research

• A variable that cannot be observed in an experiment

• A variable that changes the relationship between dependent and independent variables

• A variable that other variables in the experiment cannot change

Tags

NGSS.HS-PS1-3

What is an intervening variable?

• A variable that reflects the outcome of the research

• A variable that cannot be observed in an experiment

• A variable that changes the relationship between dependent and independent variables

• A theoretical variable used to explain a cause or connection between other study variables

What is a moderating variable?

• A variable that reflects the outcome of the research

• A variable that cannot be observed in an experiment

• A variable that changes the relationship between dependent and independent variables

• A variable that changes the relationship between dependent and independent variables by strengthening or weakening the intervening variable's effect

Answer explanation

Look at this example, IQ is moderating variable that would affect dependent variable i.e. exam score. In this case, a person IQ might influence his or her performance in an examination too even though he or she studies the same hour with another person of different IQ.

Let's say, Adam has 140 IQ score and Allen has 90 IQ score (different in IQ). Both of them study 4 hours per day (similar in study hours). But, due to the different of IQ level, Adam might have better exam score as compared to Allen. So, we can conclude that IQ as a moderating variable affects the strength or direction of the relationship between IV (hours of study) and DV (Exam score).

What is a control variable?

• A variable that reflects the outcome of the research

• A variable that cannot be observed in an experiment

• A variable that changes the relationship between dependent and independent variables

• A characteristic that is constant and does not change during a study

What are extraneous variables?

• Factors that affect the dependent variable but were not originally considered in the experiment

• Variables that reflect the outcome of the research

• Variables that cannot be observed in an experiment

• Variables that change the relationship between dependent and independent variables

What is a confounding variable?

• A variable that reflects the outcome of the research

• A variable that cannot be observed in an experiment

• A third variable that influences both the independent and dependent variables

• A variable that changes the relationship between dependent and independent variables

What is a composite variable?

• A variable that reflects the outcome of the research

• A variable that cannot be observed in an experiment

• Two or more variables combined to make a more complex variable

• A variable that changes the relationship between dependent and independent variables

Answer explanation

Composite variable is a variable made up of two or more variables or measures that are highly related to one another conceptually or statistically. In this case, it is assumed that self-discipline, social media usage and study habits are highly related variables which affect other dependent variable i.e. academic performance.

Which type of variable is mostly used in experimental research?

• Independent variable

• Dependent variable

• Intervening variable

• Control variable

What is the role of control variables in experiments?

• To ensure that the experiment results are fair and unbiased

• To explain a cause or connection between other study variables

• To change the relationship between dependent and independent variables

• To measure the outcome of the research