Variables

Variables are characteristics or a quantity of a phenomenon that is the focus of a research project. It can be measured or categorized, and their values vary across unit, or across time. It can also measure abstract concepts- for examples, self-esteem, well-being, sense of religiosity, intelligence, etc.

USES of variables: (1) classifying, (2) measuring, (3) explaining, (4) assessing relationship

Importance of Choosing the Right Variables:

1 Related Studies- are useful when you are searching for other studies, (for example in journal articles) that are similar to yours. Thus, the variables can serve as search terms.

2 Focus- variables provide focus to the study. So if you pick the wrong ones, the findings of the study may go to a direction that was not expected by you.

3 Measurement- it is also important to focus on the methods and tools for measuring the selected variables. Picking the wrong ones may also take the findings into an unintended direction.

Classifications:

Numeric Variables: Discrete & Continuous

**Discrete Variables -**quantitative variables whose observations can assume only a countable numbers, ad values cannot take the decimal form

**Continuous Variables -**quantitative variables whose observations can assume any one of the countless number of values in a line interval.

Categorical Variables: Nominal, Interval, Ordinal, Ratio; Dichotomous, Polychotomous

Dichotomous variables- variables represent only two categories

Polychotomous variables- variables that have many categories

Nominal Variables variable whose data are non-numeric labels that do not reflect quantitative information

Interval Variables variable whose data values are ranged in real interval and can be as large as from negative infinity to positive infinity

Ordinal Variables variables where there is a meaningful order, or category but no measurable distance in between arithmetic operation are impossible because of lack of equal distances, but logical operations can be performed

Ratio Variables the highest level of measurement that has all the characteristics of the interval plus a true zero point both the differences and the ratio of two values are meaningful and there is always an absolute zero that is meaningful

Experimental Variables:

**Independent Variables -**manipulated variable that cause change in another variable

**Dependent Variables -**those that are affected by independent variables

Intervening/Extraneous Variables: are called test or control variables that either increase or decrease the effect of independent variable and dependent variable

Non-experimental Variables:

Predictor Variables variables changes the other variable/s in a non-experimental study

**Criterion Variables -**variables are usually influenced by the predictor variables

Variables according to the number being studied:

Univariate study - only one variable is studied

Bivariate Study - two variables are being studied

Polyvariate Study - more than two variables are being studied