In a hypothetical experimental study on the effect of group study habits on college students' academic performance, the explanatory variable would be the study method, and the response variable would be academic performance. Interval or ratio level variables are most appropriate, as they allow for quantitative measurement of academic results and study time.
When developing an experimental research study, one must carefully consider the variables involved. Scientific sociological studies frequently observe the interaction between variables, especially how one may influence or change another. Once a researcher defines the operational terms and establishes dependent and independent variables, they can choose an appropriate research method and level of measurement for their data.
Designing an Experiment
Let's say we're examining the effect of group study habits on academic performance amongst college students. We would identify a population of college students and assign them randomly to either a Control group with individual study or an Experimental group with facilitated group study sessions. There will be two types of variables: explanatory variable (study method) and response variable (academic performance).
The research variables chosen would be at the interval or ratio level of measurement, as academic performance can be quantified through grades or test scores, which are numerical and have meaningful distances between measurements. Also, the number of study hours can be measured on a ratio scale as it has a true zero point (no study time) and the differences between any two points are meaningful.
Reliability and Validity
In any study, measures are taken to ensure reliability and validity. Tools and methods that accurately measure the variables of interest such as grades or test scores, help to maintain the study's reliability. The hypothesis might state that group study will lead to higher academic performance compared to individual study.
Throughout the experimentation phase, treatments will be applied (different study methods), and academic performance will be monitored and compared between the control and experimental groups. To minimize biases, such as the power of suggestion, blinding is used where students do not know if their study method is hypothesized to be more effective.