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Research Methods Information: Choosing a Research Design

A comprehensive resource for faculty and students who are teaching and conducting research.

Research Design

Introduction to Research Design


Before beginning your paper, you need to decide how you plan to design the study.

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. Note that your research problem determines the type of design you can use, not the other way around!

The function of a research design is to ensure that the evidence obtained enables you to effectively address the research problem as unambiguously as possible. In social sciences research, obtaining evidence relevant to the research problem generally entails specifying the type of evidence needed to test a theory, to evaluate a program, or to accurately describe a phenomenon.

However, researchers can often begin their investigations far too early, before they have thought critically about about what information is required to answer the study's research questions. Without attending to these design issues beforehand, the conclusions drawn risk being weak and unconvincing and, consequently, will fail to adequate address the overall research problem.

 Given this, the length and complexity of research designs can vary considerably, but any sound design will do the following things:

  1. Identify the research problem clearly and justify its selection,
  2. Review previously published literature associated with the problem area,
  3. Clearly and explicitly specify hypotheses [i.e., research questions] central to the problem selected,
  4. Effectively describe the data which will be necessary for an adequate test of the hypotheses and explain how such data will be obtained, and
  5. Describe the methods of analysis which will be applied to the data in determining whether or not the hypotheses are true or false.

The organization and structure of the section of your paper devoted to describing the research design will vary depending on the type of design you are using. However, you can get a sense of what to do by reviewing the literature of studies that have utilized the same research design. This can provide an outline to follow for your own paper.


Sources: De Vaus, D. A. Research Design in Social Research. London: SAGE, 2001; Gorard, Stephen. Research Design: Creating Robust Approaches for the Social Sciences. Thousand Oaks, CA: Sage, 2013; Leedy, Paul D. and Jeanne Ellis Ormrod. Practical Research: Planning and Design. Tenth edition. Boston, MA: Pearson, 2013; Vogt, W. Paul, Dianna C. Gardner, and Lynne M. Haeffele. When to Use What Research Design. New York: Guilford, 2012.


Labaree, Robert. Types of Research Designs. Organizing Your Social Sciences Research Papers: Types of Designs research guide. USC Libraries, 2016.
The content of this section was created by Dr. Labaree and used with his permission.

The Research Cycle Illustrated


The research cycle is rarely linear and often some (or all) stages will need to be revisited. Remember too that different disciplines and research topics may employ different approaches to research, which will impact on the process.

 

Circular chart of research cycle

 


Image & intro text credit: The Research Cycle. Curtin Library of Curtin University, Perth, West Australia

Types of Research Design


ACTION RESEARCH DESIGN

Definition and Purpose

The essentials of action research design follow a characteristic cycle whereby initially an exploratory stance is adopted, where an understanding of a problem is developed and plans are made for some form of interventionary strategy. Then the intervention is carried out (the action in Action Research) during which time, pertinent observations are collected in various forms. The new interventional strategies are carried out, and the cyclic process repeats, continuing until a sufficient understanding of (or implement able solution for) the problem is achieved. The protocol is iterative or cyclical in nature and is intended to foster deeper understanding of a given situation, starting with conceptualizing and particularizing the problem and moving through several interventions and evaluations.


CASE STUDY DESIGN

Definition and Purpose

A case study is an in-depth study of a particular research problem rather than a sweeping statistical survey. 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 a phenomenon.


CAUSAL STUDY DESIGN

Definition and Purpose

Causality studies may be thought of as understanding a phenomenon in terms of conditional statements in the form, “If X, then Y.” This type of research is used to measure what impact a specific change will have on existing norms and assumptions. Most social scientists seek causal explanations that reflect tests of hypotheses. Causal effect (nomothetic perspective) occurs when variation in one phenomenon, an independent variable, leads to or results, on average, in variation in another phenomenon, the dependent variable.

Conditions necessary for determining causality:

  • Empirical association--a valid conclusion is based on finding an association between the independent variable and the dependent variable.
  • Appropriate time order--to conclude that causation was involved, one must see that cases were exposed to variation in the independent variable before variation in the dependent variable.
  • Nonspuriousness--a relationship between two variables that is not due to variation in a third variable.

COHORT DESIGN

Definition and Purpose

Often used in the medical sciences, but also found in the applied social sciences, a cohort study generally refers to a study conducted over a period of time involving members of a population which the subject or representative member comes from, and who are united by some commonality or similarity. Using a quantitative framework, a cohort study makes note of statistical occurrence within a specialized subgroup, united by same or similar characteristics that are relevant to the research problem being investigated, rather than studying statistical occurrence within the general population. Using a qualitative framework, cohort studies generally gather data using methods of observation. Cohorts can be either "open" or "closed."

  • Open Cohort Studies [dynamic populations, such as the population of Los Angeles] involve a population that is defined just by the state of being a part of the study in question (and being monitored for the outcome). Date of entry and exit from the study is individually defined, therefore, the size of the study population is not constant. In open cohort studies, researchers can only calculate rate based data, such as, incidence rates and variants thereof.
  • Closed Cohort Studies [static populations, such as patients entered into a clinical trial] involve participants who enter into the study at one defining point in time and where it is presumed that no new participants can enter the cohort. Given this, the number of study participants remains constant (or can only decrease).

CROSS-SECTIONAL DESIGN

Definition and Purpose

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 diffrerences between or from among a variety of people, subjects, or phenomena rather than change. As such, researchers using this design can only employ a relative passive approach to making causal inferences based on findings.


DESCRIPTIVE DESIGN

Definition and Purpose

Descriptive research designs help provide answers to the questions of who, what, when, where, and how associated with a particular research problem; a descriptive study cannot conclusively ascertain answers to why. Descriptive research is used to obtain information concerning the current status of the phenomena and to describe "what exists" with respect to variables or conditions in a situation.


EXPERIMENTAL DESIGN

Definition and Purpose

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.


EXPLORATORY DESIGN

Definition and Purpose

An exploratory design is conducted about a research problem when there are few or no earlier studies to refer to. The focus is on gaining insights and familiarity for later investigation or undertaken when problems are in a preliminary stage of investigation.

The goals of exploratory research are intended to produce the following possible insights:

  • Familiarity with basic details, settings and concerns.
  • Well grounded picture of the situation being developed.
  • Generation of new ideas and assumption, development of tentative theories or hypotheses.
  • Determination about whether a study is feasible in the future.
  • Issues get refined for more systematic investigation and formulation of new research questions.
  • Direction for future research and techniques get developed.

HISTORICAL DESIGN

Definition and Purpose

The purpose of a historical research design is to collect, verify, and synthesize evidence from the past to establish facts that defend or refute your hypothesis. It uses secondary sources and a variety of primary documentary evidence, such as, logs, diaries, official records, reports, archives, and non-textual information [maps, pictures, audio and visual recordings]. The limitation is that the sources must be both authentic and valid.


LONGITUDINAL DESIGN

Definition and Purpose

A longitudinal study follows the same sample over time and makes repeated observations. With longitudinal surveys, for example, 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 and is sometimes referred to as a panel study.


OBSERVATIONAL DESIGN

Definition and Purpose

This type of research design draws a conclusion by comparing subjects against a control group, in cases where the researcher has no control over the experiment. There are two general types of observational designs. In direct observations, people know that you are watching them. Unobtrusive measures involve any method for studying behavior where individuals do not know they are being observed. An observational study allows a useful insight into a phenomenon and avoids the ethical and practical difficulties of setting up a large and cumbersome research project.


PHILOSOPHICAL DESIGN

Definition and Purpose

Understood more as an broad approach to examining a research problem than a methodological design, philosophical analysis and argumentation is intended to challenge deeply embedded, often intractable, assumptions underpinning an area of study. This approach uses the tools of argumentation derived from philosophical traditions, concepts, models, and theories to critically explore and challenge, for example, the relevance of logic and evidence in academic debates, to analyze arguments about fundamental issues, or to discuss the root of existing discourse about a research problem. These overarching tools of analysis can be framed in three ways:

  • Ontology -- the study that describes the nature of reality; for example, what is real and what is not, what is fundamental and what is derivative?
  • Epistemology -- the study that explores the nature of knowledge; for example, on what does knowledge and understanding depend upon and how can we be certain of what we know?
  • Axiology -- the study of values; for example, what values does an individual or group hold and why? How are values related to interest, desire, will, experience, and means-to-end? And, what is the difference between a matter of fact and a matter of value?

SEQUENTIAL DESIGN

Definition and Purpose

Sequential research is that which is carried out in a deliberate, staged approach [i.e. serially] where one stage will be completed, followed by another, then another, and so on, with the aim that each stage will build upon the previous one until enough data is gathered over an interval of time to test your hypothesis. The sample size is not predetermined. After each sample is analyzed, the researcher can accept the null hypothesis, accept the alternative hypothesis, or select another pool of subjects and conduct the study once again. This means the researcher can obtain a limitless number of subjects before finally making a decision whether to accept the null or alternative hypothesis. Using a quantitative framework, a sequential study generally utilizes sampling techniques to gather data and applying statistical methods to analze the data. Using a qualitative framework, sequential studies generally utilize samples of individuals or groups of individuals [cohorts] and use qualitative methods, such as interviews or observations, to gather information from each sample.

Labaree, Robert. Types of Research Designs. Organizing Your Social Sciences Research Papers: Types of Designs research guide. USC Libraries, 2016.
The content of this section was created by Dr. Labaree and used with his permission.

Design Flaws to Avoid


Design Flaws to Avoid

The research design establishes the decision-making processes, conceptual structure of investigation, and methods of analysis used to address the central research problem of your study. 

Taking the time to develop a thorough research design helps to organize your thoughts, set the boundaries of your study, maximize the reliability of your findings, and avoid misleading or incomplete conclusions.

Therefore, if any aspect of your research design is flawed or under-developed, the quality and reliability of your final results and, by extension, the overall value of your study will be weakened.


In no particular order, here are some common problems to avoid when designing a research study.

  • Lack of Specificity -- do not describe the investigative aspects of your study in overly-broad generalities. Avoid using vague qualifiers, such as, extremely, very, entirely, completely, etc. It's important that you design a study that describes the process of investigation in clear and concise terms. Otherwise, the reader cannot be certain what you intend to do.
  • Poorly Defined Research Problem -- the starting point of most new research is to formulate a problem statement and begin the process of formulating questions to address that problem. Your paper should outline and explicitly delimit the problem and state what you intend to investigate since it will determine what research design you will use [research problem always precedes choice of design].
  • Lack of Theoretical Framework -- the theoretical framework represents the conceptual foundation of your study. Therefore, your research design should include an explicit set of basic postulates or assumptions related to the research problem and an equally explicit set of logically derived hypotheses.
  • Significance -- the research design must include a clear answer to the "So What?" question. Be sure you clearly articulate why your study is important and how it contributes to the larger body of literature about the topic being investigated.
  • Relationship between Past Research and Your Study -- do not simply offer a summary description of prior research. Your literature review should include an explicit statement linking the results of prior research to the research you are about  to undertake. This can be done, for example, by indentifying basic weaknesses in previous research studies and how your study helps to fill this gap in knowledge.
  • Contribution to the Field -- in placing your study within the context of prior research, don't just note that a gap exists; be clear in describing how your study contributes to, or possibly challenges, existing assumptions or findings.
  • Provincialism -- this refers to designing a narrowly applied scope, geographical area, sampling, or method of analysis that unduly restricts your ability to create meaningful outcomes and, by extension, obtaining results that are relevant and possibly transferable to understanding phenomena in other settings.
  • Objectives, Hypotheses, or Questions -- your research design should include one or more questions or hypotheses that you are attempting to answer about the research problem underpinning your study. They should be clearly articulated and closely tied to the overall aims of your paper. Although there is no rule regarding the number of questions or hypotheses associated with a research problem, most studies in the social sciences address between one and five.
  • Poor Method -- the design must include a well-developed and transparent plan for how you intend to collect or generate data and how it will be analyzed.
  • Proximity Sampling -- this refers to using a sample which is based not upon the purposes of your study, but rather, is based upon the proximity of a particular group of subjects. The units of analysis, whether they be persons, places, or things, must not be based solely on ease of access and convenience.
  • Techniques or Instruments -- be clear in describing the techniques [e.g., semi-structured interviews] or instruments [e.g., questionnaire] used to gather data. Your research design should note how the technique or instrument will provide reasonably reliable data to answer the questions associated with the central research problem.
  • Statistical Treatment -- in quantitative studies, you must give a complete description of how you will organize the raw data for analysis. In most cases, this involves describing the data through the measures of central tendencies like mean, median, and mode that help the researcher explain how the data are concentrated and, thus, leading to meaningful interpretations of key trends or patterns found within the data.
  • Vocabulary -- research often contains jargon and specialized language that the reader is presumably familiar with. However, avoid overuse of technical or pseudo-technical terminology. Problems with vocabulary also can refer to the use of popular terms, cliche's, or culture-specific language that is inappropriate for academic writing.
  • Ethical Dilemmas -- in the methods section of qualitative research studies, your design must document how you intend to minimize risk for participants [a.k.a., "respondents"] during stages of data gathering while, at the same time, still being able to adequately address the research problem. Failure to do so can lead the reader to question the validity and objectivity of your entire study.
  • Limitations of Study -- all studies have limitations. Your research design should anticipate and explain the reasons why these limitations exist and clearly describe the extent of missing data. It is important to include a statement concerning what impact these limitations may have on the validity of your results.


SOURCES: Butin, Dan W. The Education Dissertation A Guide for Practitioner Scholars. Thousand Oaks, CA: Corwin, 2010; Carter, Susan. Structuring Your Research Thesis. New York: Palgrave Macmillan, 2012; Gorard, Stephen. Research Design: Creating Robust Approaches for the Social Sciences. Thousand Oaks, CA: Sage, 2013; Lunenburg, Frederick C. Writing a Successful Thesis or Dissertation: Tips and Strategies for Students in the Social and Behavioral Sciences. Thousand Oaks, CA: Corwin Press, 2008. Lunsford, Andrea and Robert Connors. The St. Martin’s Handbook. 3rd ed. New York: St. Martin’s Press, 1995.


Labaree, Robert. Types of Research Designs. Organizing Your Social Sciences Research Papers: Types of Designs research guide. USC Libraries, 2016.
The content of this section was created by Dr. Labaree and used with his permission.

Selected Journals & Articles on Research Design


Selected Journals in the APUS Library

Selected Articles on Research Design

Selected Books on Research Methods & Design


Selected Books in the APUS Library

 


Open Web Research Methods Textbooks

VIDEOS On Research Design


Videos on Research Design from SAGE Research Methods


How Does Design Relate to Methods?
Malcolm Williams

In Designing Your Research Proposal | Published: 2013 | Publisher: SAGE Publications Ltd.
Video Type: Interview | Duration: [00:01:75] | Transcript Provided.


How Should One go about Designing a Qualitative Research Project?
Catherine Marshall Ph.D., Gretchen B Rossman Ph.D.

In How should one go about designing a qualitative research project?
Published: 2011 | Publisher: SAGE Publications Ltd.
| Video Type: Interview | Duration: [00:04:30]
Transcript Provided.


How Do I Design Policy Focused Research?
Naomi Jones

In How do I design policy focused research? | Published: 2011 | Publisher: SAGE Publications Ltd.
Video Type: Interview |  [00:07:10] | Transcript Provided.


Videos on Research Design from Non-APUS Sources

Web Resources on Research Design