Research Design
A research design is fundamentally a plan, structure, and strategy of investigation conceived to obtain answers to research questions or problems. It serves as a conceptual structure or blueprint for the collection, measurement, and analysis of data.
This comprehensive plan outlines everything the investigator will do, from formulating hypotheses and their operational implications to the final analysis of data.
Decisions Included in a Research Design
A well-defined research design involves making crucial decisions in advance concerning the inquiry. These include:
- What the study is about and why it is being conducted.
- Where the study will be carried out.
- What type of data is required and where it can be found.
- What periods of time the study will include.
- What sample design will be used.
- What techniques of data collection will be employed.
- How the data will be analyzed.
- In what style the report will be prepared.
- The rationale and justification for each decision, ideally supported by a review of the literature.
Parts of Research Design
The overall research design can be broken down into four essential parts :
Sampling design : Method of selecting items or respondents to be observed for the given study. Dictates how a sample should be selected and its size.
Observational design : Relates to the conditions under which the observations are to be made, including specific techniques for data collection.
Statistical design : This concerns how many items are to be observed and how the gathered information and data will be analyzed. It involves planning for processing and analysis procedures.
Operational design : This encompasses the techniques by which the procedures specified in the sampling, statistical, and observational designs can be carried out
Need for a Research Design
A research design is crucial for several reasons :
Facilitates Smooth Operations: It guides the various research operations, ensuring a logical flow.
Maximizes Efficiency and Information: It aims to make research as efficient as possible, yielding the most information with minimal expenditure of effort, time, and money.
Advance Planning: It provides an advance plan for the methods to be adopted for collecting relevant data and the techniques to be used in their analysis, considering the research objectives and available resources (staff, time, and money).
Prevents Futile Research: A well-designed plan helps prevent the research exercise from becoming futile or yielding misleading conclusions due to thoughtlessness in its execution.
Allows for Critical Evaluation: It organizes ideas, making it possible to identify flaws and inadequacies, and allows others (like supervisors or critics) to provide a comprehensive review of the proposed study.
Features of a Good Research Design
A good research design is characterized by several key attributes :
Flexibility, Appropriateness, Efficiency, and Economy: These are adjectives often used to describe a good design.
Minimizes Bias and Maximizes Reliability: It should be structured to reduce bias and increase the reliability of the collected and analyzed data.
Yields Maximal Information: It should provide ample opportunity for considering different aspects of a problem.
Suitability to Research Purpose: The design must be appropriate for the specific purpose and nature of the research problem.
Considers Resources and Skills: It must take into account the means of obtaining information, the availability and skills of the researcher and staff, and the time and money available for the work.
Important Research Design Concepts
- Dependent and Independent Variables
- Extraneous Variable
- Control
- Confounded Relationship
- Research Hypothesis
- Experimental and Non-experimental Hypothesis-Testing Research
- Experimental and Control Groups
- Treatments
- Experiment
- Experimental Unit(s)
1. Dependent and Independent variables:
A variable is a concept that can take on different quantitative values.
If one variable is a consequence of or depends upon another variable, it is called a dependent variable.
The variable that precedes the dependent variable and is assumed to be the cause of change is called an independent variable.
For example,
- If height depends upon age, height is the dependent variable and age is the independent variable.
- If height also depends on an individual's sex, then age and sex are both independent variables.
Continuous variables – phenomena which can take on quantitatively different values even in decimal points. For example, age.
Discontinuous or Discrete variables – If some variables can be only expressed in integer values. For example, no. of children.
2. Extraneous variable
Extraneous variables are independent variables that are not directly related to the study's purpose but may still affect the dependent variable.
Any effect observed on the dependent variable due to extraneous variables is technically called an "experimental error".
The goal of a good research design is to minimize, quantify, or eliminate the effects of these extraneous and chance variables.
For instance, if a researcher is studying the relationship between children's social studies achievement and their self-concepts (independent and dependent variables, respectively), intelligence could also affect achievement. Since intelligence is not the primary focus, it would be considered an extraneous variable.
3. Control
Control is a crucial characteristic of a good research design, referring to the process of minimizing the influence or effect of extraneous variables.
In experimental research, "control" specifically means restraining experimental conditions to ensure that the effect on the dependent variable is attributed entirely to the independent variable(s).
Methods to achieve control include randomization and matching of groups. In physical sciences, control is often achieved in laboratories.
4. Confounded relationship
A relationship between dependent and independent variables is considered confounded when the dependent variable is not free from the influence of extraneous variables. This means that the observed effect cannot be clearly attributed solely to the independent variable because other unmeasured factors are also at play.
5. Research Hypothesis
When a prediction or a hypothesized relationship is to be tested by scientific methods, it is termed as research hypothesis.
A research hypothesis is a predictive statement or a hypothesized relationship that is formulated to be tested by scientific methods. It typically relates an independent variable to a dependent variable and must contain at least one of each.
6. Experimental and Non-experimental Hypothesis-Testing Research
Hypothesis-testing research is undertaken when the purpose is to test a research hypothesis. This type of research can be divided into two main categories:
Experimental hypothesis-testing research: In this design, the independent variable is actively manipulated by the researcher (or another party) to observe its effects on the dependent variable.
Non-experimental hypothesis-testing research: In this design, the independent variable is not manipulated. The researcher observes phenomena as they naturally occur and retrospectively attempts to establish causal links.
7. Experimental and Control Groups
In experimental hypothesis-testing research, a control group is exposed to usual conditions and does not receive the intervention, while an experimental group is exposed to some novel or special condition, which is the intervention being studied.
Both groups are measured before and after the intervention, and any significant difference between the changes observed in each group is attributed to the intervention.
8. Treatments
The different conditions to which experimental and control groups are subjected are referred to as treatments.
9. Experiment
An experiment is the process of examining the truth of a statistical hypothesis related to a research problem.
Experiments can be categorized as absolute experiments, where the impact of a single intervention is determined (e.g., effect of a fertilizer on crop yield), or comparative experiments, where the impact of one intervention is compared to another (e.g., comparing different fertilizers).
10. Experimental unit(s)
Experimental units are the pre-determined plots or blocks where different treatments are applied in an experiment.
Different Types of Research Design
Research design in case of Exploratory Research
Research design in case of Descriptive and Diagnostic research
Research design in case of Hypothesis -Testing Research studies
Research design in case of exploratory research studies
Exploratory research studies, also known as formulative research studies, aim to gain familiarity with a phenomenon or to achieve new insights into it.
Their main purpose is to formulate a problem for more precise investigation or to develop working hypotheses from an operational point of view. These studies emphasize the discovery of ideas and insights.
The major objective of exploratory research can be :
- Evaluate the feasibility of a research project
- Formulate a research statement
- Provide theoretical basis for a hypothesis
- Establish priorities/ possibilities for further research.
Generally, three methods are discussed in the context of research design for exploratory studies:
- Survey of concerning literature;
- Experience survey and
- Analysis of 'insight-stimulating' examples.
Research design in case of Descriptive and Diagnostic Research
Descriptive research studies are concerned with describing the characteristics of a particular individual, group, situation, problem, phenomenon, service, or programme. They aim to systematically portray things as they exist at present. Diagnostic research studies determine the frequency with which something occurs or its association with something else.