What are variables in research?

Variables are aspect of a testing condition that can change or take different characteristics with different conditions. There are many variables which must be identified by the researcher. The researcher’s duty is to limit the variables depending on the focus of study.

Dependent and independent variables are the two types of variables in research. Dependent variable is the measure of behavior of the subject. It is the response that the subject of study makes, and this response is generally measured using at least one of several different dimensions, whereas independent variables is the condition manipulated or selected by the researcher to determine its effect on behavior. It is believed to cause some changes in the value of the dependent variable.

Of particular importance in the organization of variable is the level of measurement. Measurement is the process of assigning numbers to events or objects according to rules. The rules by which numbers are assigned to the events determine how useful the measurement is. There are four types of measurement scales: 1) nominal or categorical scale, 2) ordinal scale, 3) interval scale, and 4) ratio scale. 

       Nominal or categorical scale is a measure that simply divides objects or events into categories according to their similarities or differences. It is the simplest kind of scale because its rule for assigning numbers (or other labels) to objects or events is the simplest. The rule is that objects or events of the same kind get the same number and objects or events of a different kind get a different number.

       Ordinal scale is a measure that both assigns objects or events a name and arranges them in order of their magnitude.

       Interval scale is a measure in which the differences between numbers are meaningful; includes both nominal and ordinal information.

       Ratio scale is a measure having a meaningful zero point as well as all of the nominal, ordinal, and interval properties.

Comparing the 4 levels of measurement: nominal gives information only about whether two events are the same or different. Ordinal gives information about two events and rankings. Interval conveys nominal and ordinal information and also allows us to make quantitative statements about the magnitude of the differences between events. Lastly, ratio contains all information of the other three scales, as well as conveying information about ratios and magnitudes.

I had to leave my class earlier that day. I hope the topic on hypothesis haven’t discussed yet :)