RESEARCH DESIGN AND INSTRUMENTS

              Quantitative research is about quantifying the relationships between an independent variable and a dependent or outcome variable. Variables are the things you measure on your subjects, for examples students, student teachers, tutors or parents. Variables can represent subject physical characteristics such as weight, height or gender or the things you are interested in such as athletic performance, science achievement, physiological or psychological variable.

             Instruments such as achievement tests, questionnaires and inventories are used to measure the variables concerning the characteristics and traits of your subjects, the nature and learning outcomes of your treatment depending on the research design. Then, to quantify the relationships between these variables, you can use statistics such as correlation coefficient, the difference between two means.

A. Quantitative Research Design

     There are two main types of quantitative research designs: descriptive and experimental. Currently, there are many adaptations of the descriptive and experimental designs that have been developed. Before you can adopt any particular design for your research, it is important to consider a range of possible research designs and their strengths and weaknesses. The types of quantitative research designs can be groups as follows:

1. Descriptive or Observational Designs
(i) case study
(ii) case series
(iii) cross-sectional
(iv) cohort or prospective
(v) retrospective or case-control

2. Experimental or Longitudinal or Repeated-measures Designs
(i) Without a control group: time series or crossover
(ii) With a control group: posttest-only, control group, design pretest-posttest contro,l group design ,Solomon four-group, design Factorial design.

       In a descriptive research, no attempt is made to change behaviuor or condition of the variables. You measure things as they are. The subjects are usually measured once.


       In an experimental study, however, you must take measurements; try some sort of treatment or intervention and take measurements again to find out what happened. The subjects are normally measured before and after a treatment. In your research, you are encouraged to try out an intervention that you think would benefit your students and schools which eventually will bring about change in the educational setting.



       Descriptive research are observational research since you just observe the subject and record your findings without attempting to manipulate any variable. The simplest design is the case study which reports data on only one subject. Descriptive research on a few cases are called case series. In cross-sectional research, variables of interest are determined once and analysed.







         In prospective or cohort studies, some variables are evaluated at the start of a study. Then after a period of time, the outcome is determined. Retrospective research or case-control research compare cases of subjects with a particular attribute with the controls or subjects without the attribute. These research normally focus on conditions in the past that might cause subjects to become cases rather than controls. A common case-control design is a comparison of outcome characteristics between those exposed to training and those having no training. So these research are cohort or prospective in nature, even though the data are gathered retrospectively at only one time point. They are also known as historical cohort research. As you can see now, in all of the descriptive research no attempt is being made by the researcher to manipulate conditions or behaviour among subjects. The subjects are usually observed and measured once as they are.