Types of Variables in Research

These flashcards cover the definitions, examples, and classification of various research variables, including independent, dependent, moderator, demographic, and extraneous variables, as well as measurement scales and variable types.

What is an observation in research?

Each person or thing we collect data on is called an observation (usually people or subjects).

What is the difference between a constant and a variable?

A constant is a characteristic that is the same for every member of a group (it does not vary), while a variable is a characteristic that differs for group members.

How is a variable defined in the context of research?

A variable is a concept or abstract idea that can be described in measurable terms, referring to characteristics, qualities, traits, or attributes of an individual, object, or situation.

Define Independent Variables.

Variables which are manipulated, controlled, or changed to study their relationship or effects; they are the presumed or possible cause.

Define Dependent Variables.

The outcome variables for which statistics are calculated; they change on account of the independent variable and are the presumed results or effect.

In a study on the effect of revision time and intelligence on test performance, what is the dependent variable?

Test Mark (measured from $0$ to $100$).

What are the independent variables in the study of teacher-student classroom interaction across schooling levels?

Level of schooling (primary, upper primary, secondary, and junior college).

What is a Moderator Variable?

A special type of independent variable that modified the relationship between the independent variable and dependent variable under different conditions.

What are Quantitative Variables?

Variables that exist along a continuum from low to high, such as height in inches or test scores; they are also called continuous variables.

What are Qualitative Variables?

Variables that do not express differences in amount but only differences in type or category, such as gender or religion; they are also known as categorical variables.

Describe the Nominal Scale.

The simplest scale used for labeling variables into distinct classifications without involving quantitative values or order.

Describe the Ordinal Scale.

A measurement scale used to depict the order of variables where the rank (importance) matters, but the exact difference between each variable is not known.

What is an Interval Scale?

A numerical scale where the order is known and the differences between variables are familiar, constant, and computable (equidistant), such as calendar years or Likert scales.

Define the Ratio Scale.

A measurement scale that produces order, known differences between variables, and includes a value for true (absolute) zero.

What is a Continuous Variable?

A variable whose values can be divided into fractions and can take an infinite number of values within a range, such as age, income, or temperature.

What is a Discontinuous (Discrete) Variable?

A variable that has a limited number of distinct values and cannot be divided into fractions.

What is the difference between Dichotomous and Trichotomous variables?

Dichotomous variables have only two values (e.g., male-female), while trichotomous variables have three categories (e.g., urban, semi urban, and rural).

What are Demographic Variables?

Characteristics or attributes of subjects collected to describe the sample (e.g., age, gender, occupation, marital status) and determine if they represent the population of interest.

Define Extraneous Variables.

Variables that may affect research outcomes but have not been adequately considered in the study.

What are Confounding Variables?

Extraneous variables that are not recognized until the study is in process or are recognized but cannot be controlled.

What are Intervening Variables?

External variables that may influence the relationship between research variables even though the researcher cannot see them.

What is a Control Variable?

A characteristic that is deliberately left unchanged (held constant) or eliminated to prevent it from having a biasing effect on other variables.