3.1 Introduction

Dear learner, welcome to session three.

In the previous session you were introduced to research as a study field and its significance including the nature of research based knowledge. In this session we will go through different research designs and research approaches. The focus of the present session will be on research designs.

Let us begin our lesson;

3.2 Session objectives

At the end of this session you should be able to:

i.Explain the meaning of research design

ii.Mention different types of research designs

iii.Describe features and attributes of each research design

iv.Describe the advantages of each research design

v.Describe the limitations of each research design

vi.Illustrate practical use of each design using examples of published papers or research reports

3.3 Series of sub-topics

3.3.1 What is a research design?

The research design refers to the overall strategy that you choose to integrate the different components of the study in a coherent and logical way, thereby, ensuring you will effectively address the research problem. It constitutes the blueprint for the collection, measurement and analysis of data.

3.3.2 Different types of research designs

There are different types of research designs, these include;

1.Experiment design

2.Case study design

3.Longitudinal design

4.Cross sectional design

3.3.2.1 Experimental Design

A blueprint of the procedure that enables the researcher to maintain control over all factors that may affect the result of an experiment. In doing this, the researcher attempts to determine or predict what may occur.

Experimental research is often used where there is time priority in a causal relationship (cause precedes effect), there is consistency in a causal relationship (a cause will always lead to the same effect), and the magnitude of the correlation is great. The classic experimental design specifies an experimental group and a control group.

The independent variable is administered to the experimental group and not to the control group, and both groups are measured on the same dependent variable. Subsequent experimental designs have used more groups and more measurements over longer periods. True experiments must have control, randomization, and manipulation.

3.3.2.1.1 Features and attributes of experimental design

A.Experimental research allows the researcher to control the situation. In so doing, it allows researchers to answer the question, "What causes something to occur?”

B.Permits the researcher to identify cause and effect relationships between variables and to distinguish placebo effects from treatment effects.

C.Experimental research designs support the ability to limit alternative explanations and to infer direct causal relationships in the study.

D.Approach provides the highest level of evidence for single studies.

3.3.2.1.2 Limitations of experimental design

A.The design is artificial, and results may not generalize well to the real world.

B.The artificial settings of experiments may alter the behaviors or responses of participants.

C.Experimental designs can be costly if special equipment or facilities are needed.

D.Some research problems cannot be studied using an experiment because of ethical or technical reasons.

E.Difficult to apply ethnographic and other qualitative methods to experimentally designed studies.

3.3.2.2 Case study Design

A case study is an in-depth study of a particular research problem rather than a sweeping statistical survey or comprehensive comparative inquiry. It is often used to narrow down a very broad field of research into one or a few easily researchable examples. The case study research design is also useful for testing whether a specific theory and model actually applies to phenomena in the real world. It is a useful design when not much is known about an issue or phenomenon.

3.3.2.2.1 Features and attributes of case study design

A.Approach excels at bringing us to an understanding of a complex issue through detailed contextual analysis of a limited number of events or conditions and their relationships.

B.A researcher using a case study design can apply a variety of methodologies and rely on a variety of sources to investigate a research problem.

C.Design can extend experience or add strength to what is already known through previous research.

D.Social scientists, in particular, make wide use of this research design to examine contemporary real-life situations and provide the basis for the application of concepts and theories and the extension of methodologies.

E.The design can provide detailed descriptions of specific and rare cases.

3.3.2.2.2 Limitations of case study design

A.A single or small number of cases offers little basis for establishing reliability or to generalize the findings to a wider population of people, places, or things.

B.Intense exposure to the study of a case may bias a researcher's interpretation of the findings.

C.Design does not facilitate assessment of cause and effect relationships.

D.Vital information may be missing, making the case hard to interpret.

E.The case may not be representative or typical of the larger problem being investigated.

F.If the criterion for selecting a case is because it represents a very unusual or unique phenomenon or problem for study, then your interpretation of the findings can only apply to that particular case.

3.3.2.3 Cross Sectional Design

Cross-sectional research designs have three distinctive features: no time dimension; a reliance on existing differences rather than change following intervention; and, groups are selected based on existing differences rather than random allocation. The cross-sectional design can only measure differences between or from among a variety of people, subjects, or phenomena rather than a process of change. As such, researchers using this design can only employ a relatively passive approach to making causal inferences based on findings.

3.3.2.3.1 Features and attributes of cross sectional design

A.Cross-sectional studies provide a clear 'snapshot' of the outcome and the characteristics associated with it, at a specific point in time.

B.Unlike an experimental design, where there is an active intervention by the researcher to produce and measure change or to create differences, cross-sectional designs focus on studying and drawing inferences from existing differences between people, subjects, or phenomena.

C.Entails collecting data at and concerning one point in time. While longitudinal studies involve taking multiple measures over an extended period of time, cross-sectional research is focused on finding relationships between variables at one moment in time.

D.Groups identified for study are purposely selected based upon existing differences in the sample rather than seeking random sampling.

E.Cross-sectional studies are capable of using data from a large number of subjects and, unlike observational studies, is not geographically bound.

F.Can estimate prevalence of an outcome of interest because the sample is usually taken from the whole population.

3.3.2.3.2 Limitations of cross sectional design

A.Finding people, subjects, or phenomena to study that are very similar except in one specific variable can be difficult.

B.Results are static and times bound and, therefore, give no indication of a sequence of events or reveal historical or temporal contexts.

C.Studies cannot be utilized to establish cause and effect relationships.

D.This design only provides a snapshot of analysis so there is always the possibility that a study could have differing results if another time-frame had been chosen.

E.There is no follow up to the findings.

3.3.2.4 Longitudinal Study Design

A longitudinal study follows the same sample over time and makes repeated observations. For example, with longitudinal surveys, the same group of people is interviewed at regular intervals, enabling researchers to track changes over time and to relate them to variables that might explain why the changes occur. Longitudinal research designs describe patterns of change and help establish the direction and magnitude of causal relationships. Measurements are taken on each variable over two or more distinct time periods. This allows the researcher to measure change in variables over time. It is a type of observational study sometimes referred to as a panel study.

3.3.2.4.1 Features and attributes of longitudinal study design

A.Longitudinal data facilitate the analysis of the duration of a particular phenomenon.

B.Enables survey researchers to get close to the kinds of causal explanations usually attainable only with experiments.

C.The design permits the measurement of differences or change in a variable from one period to another [i.e., the description of patterns of change over time].

D.Longitudinal studies facilitate the prediction of future outcomes based upon earlier factors.

3.3.2.4.2 Limitations of longitudinal study design

A.The data collection method may change over time.

B.Maintaining the integrity of the original sample can be difficult over an extended period of time.

C.It can be difficult to show more than one variable at a time.

D.This design often needs qualitative research data to explain fluctuations in the results.

E.A longitudinal research design assumes present trends will continue unchanged.

F.It can take a long period of time to gather results.

G.There is a need for a large sample size and accurate sampling to reach representativeness.

3.4 Session Summary

In this session we have covered the concept of research design, different types of research designs; features and attributes of each research design; the limitations of each research design. We have also illustrated practical examples where each design has been applied in research.

3.5 Exercises

3.5.1 Self-assessment exercise

1.When is it appropriate to use experimental design?

2.What are the limitations of using cross sectional design design?

3.Mention five attributes of a longitudinal design

3.5.2 Assignment

Using published papers, identify a research design that was used and explain why the author(s) decided to use such design.

3.6References

1.De Vaus, D. A. Research Design in Social Research. London: SAGE, 2001; Trochim, William M.K. Research Methods Knowledge Base. 2006.

2.Anastas, Jeane W. Research Design for Social Work and the Human Services. Chapter 4, Flexible Methods: Case Study Design. 2nd ed. New York: Columbia University Press, 1999

3.Yin, Robert K. Case Study Research: Design and Theory. Applied Social Research Methods Series, no. 5. 3rd ed. Thousand Oaks, CA: SAGE, 2003.

4.Hall, John. "Cross-Sectional Survey Design.” In Encyclopedia of Survey Research Methods. Paul J. Lavrakas, ed. (Thousand Oaks, CA: Sage, 2008), pp. 173-174.

5.Ployhart, Robert E. and Robert J. Vandenberg. "Longitudinal Research: The Theory, Design, and Analysis of Change.” Journal of Management 36 (2010): 94-120.