These variables are the ones under study considered as the cause in the causal
relationship being established. It is either active or attribute independent variables. Active
independent variables are the interventions used for the study units while attribute
independent variables are the intrinsic characteristics of the study units considered as
Independent variables can also be called predictor or criterion variable if the
research questions are predictive in nature which means these variables are thought to
predict another results. Other names dependent on the nature of study include controlled
variables, explanatory variables, input variables, or treatments.
Dependent variables are the ones influenced by the independent variables. This
means that this dependent variable changes based on the independent variable. This can
also be called as outcome variable in a predictive research question.
Additionally, dependent variables are results of the influence of the independent
variables. These provide answer on what change occur after an intervention is given.
Sample variables are the characteristics of the study units other than independent
and dependent variables.
These are used as basis to identify the appropriate study units for study to be
Extraneous variables are not of much attention to the study however must be dealt
considerably because it may influence the dependent variable. Hence, it is advisable to
control these extraneous variables in quantitative research to secure the reliability and
validity of results. In most cases, review of related literature gives idea to researchers
what extraneous variables are to be accounted for and dealt to avoid unintentional
influences to the results of the study.
Cofounding variables are extraneous variables which can cause the effect
researchers are looking for if not controlled, which result to false findings of the study.