Chapter Two Literature Review, is a critical component of a research thesis or dissertation. It serves to systematically review, analyze, and synthesize existing scholarly works relevant to the research topic. 

The chapter begins by defining the scope and context of the literature review, highlighting its purpose in establishing the foundation for the study. 

Develop concise and informative headings and subheadings, incorporating variables from the Research Questions formulated in Chapter One.  

Synthesize the reviewed literature to identify themes, theoretical perspectives, conceptual frameworks, or models, and debates or controversies that align with the research topic and study objectives.

Critically examines methodological approaches used in previous studies and evaluates their strengths and gaps or limitations. 

Throughout the chapter, the researcher showcases their understanding of the current state of knowledge on the topic and identifies gaps or unresolved issues that the present study aims to address. The literature review sets the stage for the research methodology, providing a rationale for the chosen approach and guiding the overall structure of the research.

The Literature Review

The literature review is precisely what its name suggests: a “re” view or a reconsideration of what has already been written on a particular topic. Importantly, it should not be confused with a literary review, which typically involves evaluating a literary work like a play, novel, or book of poems.

It serves as a compilation of research that has been published on a specific topic by recognized scholars and researchers. Unlike a mere descriptive list or a set of summaries, a literature review is characterized by a guiding concept, such as your research objective, the problem or issue you are addressing, or your argumentative thesis.

Literature reviews play several crucial roles. They provide background information for the problem under investigation, placing it in a historical context and sometimes illustrating how similar problems were addressed in the past. They convey to the readers the established knowledge and ideas on the chosen topic. The literature review is a tool to identify both strengths and weaknesses related to the issues being addressed. It establishes ways of dealing with a specific problem and forms the bases for interpreting the findings of your study. 

Scope and Context of the Literature Review

The scope of a literature review refers to the boundaries or extent of the research that the review covers. It defines what will be included and excluded in the review, helping to focus the attention on a specific set of studies, sources, or topics. The scope is determined by factors such as the research question, objectives, and the depth or breadth of coverage desired. Here are key elements that contribute to defining the scope of a literature review:

  1. Research Question or Objectives- The specific question or objectives of the research guide the scope. The literature included should directly contribute to addressing these questions or objectives.

  2. Inclusion and Exclusion Criteria- Clearly define the criteria for including or excluding studies. This may involve specifying publication dates, types of sources (e.g., peer-reviewed articles, books), geographical regions, or specific methodologies.

  3. Time Frame- Determine the time frame covered by the literature review. It may be recent studies only, a historical overview, or a specific period that aligns with the research focus.

  4. Geographical Scope- Specify the geographical scope if relevant to the research. For example, the review might focus on studies conducted in a particular country or region.

  5. Type of Sources- Define the types of sources to be included, such as academic journals, books, reports, or grey literature. This depends on the nature of the research and the available literature.

  6. Conceptual Boundaries– Clarify the conceptual boundaries by specifying the key concepts, variables, or themes that the literature review will cover. This helps in maintaining a clear focus.

  7. Depth of Coverage- Decide on the depth of coverage. Will the review be comprehensive, covering a broad range of studies, or will it be more selective and focused on specific aspects of the topic?

Context of the Literature Review

The context of a literature review, on the other hand, refers to the background, setting, or environment in which the review is situated. It provides the reader with an understanding of the broader context within which the research question arises and the literature is being reviewed. The context may include:

  • Historical Background- A brief overview of the historical development of the research topic.

  • Theoretical Framework Mention of any theoretical perspectives that underpin the review.

  • Relevance to Field or Discipline- How the research question aligns with the broader field or discipline.

  • Motivation for the Review- Why the review is essential, and what gap in knowledge it aims to address.

  • Practical Implications: Consideration of how the findings from the literature review may have practical applications.

  • Broader Trends or Debates- Any overarching trends or debates in the field that set the stage for the literature review.

By defining the scope and context clearly, a literature review becomes a focused and relevant exploration of existing research, providing a foundation for the current study and helping readers understand its significance in the larger context of scholarly inquiry.

How to write a literature review. A guide to write a literature review. Research Methods, Chapter two

The initial aim of this chapter is to precisely define the scope and context of the literature review, emphasizing its crucial role in laying the foundation for the entire study. A well-defined scope ensures that the literature review is focused and relevant to the research questions, providing a solid framework for subsequent chapters. Let us explore the various parts of the literature review guide. 

Planning for the Literature Review

In embarking on the literature review, the identification of key variables derived from the research title, objectives, or research questions plays a pivotal role. These variables serve as the foundation upon which the subsequent discussion is constructed. By systematically analyzing and categorizing these variables, the researcher establishes a structured framework for understanding the existing body of knowledge and its relevance to the research topic.

The process involves scrutinizing each variable within the context of previous research, theoretical frameworks, and empirical findings. Through this systematic exploration, the researcher gains insights into the various dimensions and facets of the identified variables. Additionally, understanding how these variables have been conceptualized and measured in prior studies contributes to the development of a comprehensive perspective on the research landscape.

Identification of variables serves as a guide for organizing the literature review. By structuring the discussion around these variables, the researcher can explore the nuances, patterns, and divergences in existing literature related to each specific element. This approach facilitates a focused and systematic review that aligns with the research’s core components, contributing to the clarity and coherence of the literature review

The Research Title and Research Variables

What is a variable?

A variable is a characteristic, attribute, or quantity that can take different values or levels, and it is typically used to measure, describe, or analyze a phenomenon. Variables can vary among individuals, objects, or situations and are fundamental components of the research process. They are used to understand the relationships between different factors and to assess the impact of interventions or changes. Variables are broadly categorized as:

  1. Independent Variable is the variable that the researcher manipulates or controls in an experiment. It is the presumed cause that is expected to have an effect on the dependent variable. In experimental designs, researchers actively change the levels of the independent variable to observe the resulting changes in the dependent variable.
  2. Dependent Variable is the variable that is observed, measured, or recorded in response to changes in the independent variable. It represents the outcome or the effect that the researcher is interested in studying.
  3. Intervening Variables (Mediating Variables), also known as mediating variables, are attributes or characteristics that act as intermediaries between the independent and dependent variables. These variables come into play during the causal pathway, influencing the relationship between the variables of interest. They provide insights into the mechanisms through which the independent variable affects the dependent variable, offering a deeper understanding of the underlying processes.
  4. Confounding Variables (Spurious Variables), often referred to as spurious variables, pose a challenge as their effects are challenging to isolate from other variables. These attributes or characteristics cannot be directly measured by the researcher due to their intricate interplay with other variables. Despite this complexity, confounding variables have the potential to impact the relationship between the independent and dependent variables. Addressing and controlling for confounding variables are crucial steps in ensuring the accuracy and validity of research findings.

Variables may also be described as listed below; these descriptions are based on the inherent characteristics of the variables:

types of variables, nominal, ordinal, ratio, interval, discrete and continuous variables.

Recall this Research Title from Chapter One:

“A cross-sectional analysis of urban obesity: Investigating the Impact of Access to Nutritious Food and Physical Activity Opportunities on Obesity Rates among Adults (18-65) in Low-Income Neighborhoods of Kingston and St. Andrew.”

We will dissect the research title to identify the variables. Firstly, we will classify them as independent (exposure) or dependent variables (outcome). 

Dependent Variable- Obesity Rates (among Adults (18-65) in Low-Income Neighborhoods of Kingston and St. Andrew).

Independent Variables- Access to Nutritious Foods, and Physical Activity Opportunities.

Key search terms could include:

  1. Urban obesity
  2. Impact of access to nutritious food
  3. Physical activity opportunities
  4. Obesity rates
  5. Adults (18-65)
  6. Low-income neighborhoods
  7. Kingston and St. Andrew

The Research Objectives and Research Variables

Objective One

Dependent Variable- Obesity rates among adults (18-65) in low-income neighborhoods of Kingston and St. Andrew.

Independent Variables- None explicitly defined, prompting the reviewer to explore a broader understanding of other factors that may influence obesity rates, which serves as the outcome variable. This lack of specificity encourages a comprehensive examination of various potential determinants affecting obesity rates. It highlights the need to consider multiple perspectives and influences.

Key Search Terms:

  1. Obesity rates
  2. Adults (18-65)
  3. Low-income neighborhoods
  4. Kingston and St. Andrew
  5. Urban health
  6. Socioeconomic factors and obesity
  7. Health disparities
  8. Nutrition access
  9. Physical activity opportunities
Objective Two

Independent Variables- Accessibility and availability of nutritious food options:

  • Proximity to grocery stores
  • Proximity to farmers’ markets
  • Affordability of healthy food choices

Dependent Variables

None explicitly mentioned, but potential outcomes could include insights into the accessibility and affordability of nutritious food.

Key Search Terms include:

  • Nutritious food accessibility
  • Nutritious food availability
  • Proximity to grocery stores
  • Proximity to farmers’ markets
  • Affordability of healthy food
  • Low-income neighborhoods
Objective Three

Independent Variables- Opportunities for physical activity

  • Presence of recreational facilities
  • Walkability of neighborhoods
  • Availability of spaces conducive to exercise

Dependent Variables

None explicitly mentioned, but potential outcomes could include insights into the opportunities and factors influencing physical activity.

Key Search Terms:

  • Physical activity opportunities
  • Recreational facilities
  • Walkability
  • Exercise-friendly spaces
  • Urban spaces and exercise
  • Neighborhood walkability

The Research Questions, Headings and Structure

Let us look at some possible Headings, Sub-Headings and Related Search Terms:

Sectional Heading- Access to Nutritious Food Options

  • Sub-Heading 1- Proximity to Grocery Stores
  • Sub-Heading 2- Farmers’ Markets and Nutrition
  • Key Search Terms- nutritious food options, proximity, grocery stores, farmers’ markets, low-income neighborhoods

Sectional Heading-  Affordability of Healthy Food Choices

  • Sub-Heading- Impact on Dietary Habits
  • Key Search Terms- healthy food choices, affordability, dietary habits, adults, study area

Sectional Heading- Recreational Facilities and Physical Activity

  • Sub-Heading- Correlation Analysis
  • Key Search Terms- recreational facilities, physical activity, low-income neighborhoods

You may use any visualization tool to brainstorm, record and refine your ideas. See the example below:

Note carefully, your headings in a quantitative literature review have quantifiable terms, while the qualitative literature review headings hint at the exploration of perspectives and experiences. Some other headings or sub-headings we might include are:  

  •  Neighborhood Walkability and Physical Activity
  • Walkability Index and Self-Reported Activity
  • Lived Experiences of Obesity
  • Perceptions in Studied Communities
  • Socio-Cultural Factors and Attitudes
  • Food Accessibility and Affordability
  • Influence on Dietary Choices
  • Spaces for Physical Activity
  • Experiences and Perceptions

Selecting credible, reliable, and valid literature is essential for a robust literature review. The integrity of your research hinges on the trustworthiness of the sources you consult. Credible literature ensures that the information you incorporate is accurate, reducing the risk of misinformation or inaccuracies in your study. It not only builds a strong foundation for your research but also enhances its overall quality, contributing to the validity and reliability of your findings. Engaging with reputable sources allows you to contextualize your study within existing knowledge, guide the formulation of meaningful research questions, and demonstrate scholarly awareness. Moreover, it supports the rigorous analysis of methodologies and theoretical frameworks, showcasing your commitment to academic integrity and ethical research practices. Selecting quality literature extends beyond the literature review, influencing the entire research process and contributing to the academic rigor and impact of your study.

The evidence based pyramid, types of research evidence, sources of literature.The evidence-based pyramid primarily falls under the category of primary literature (at the base) and then converges towards secondary literature at the apex, including reviews and highly filtered meta-analyses.

Primary literature consists of original research studies, experiments, clinical trials, and other scholarly works directly reporting on new findings. The evidence-based pyramid is a hierarchical representation of different types of evidence, with systematic reviews and meta-analyses at the top, followed by randomized controlled trials, cohort studies, case-control studies, and finally, expert opinions and anecdotal evidence at the base. 

The pyramid reflects the strength of evidence, with systematic reviews and meta-analyses considered the most robust due to their comprehensive synthesis and filtering of existing research. As you move down the pyramid, the strength of evidence decreases. Primary literature, including randomized controlled trials and other original research, plays a crucial role in generating new knowledge and contributes to the higher tiers of the evidence-based pyramid. Researchers often rely on primary literature to inform evidence-based practices and policies in various fields.

Careful selection of quality, credible sources of literature is paramount to ensure the reliability and validity of the study. Researchers should prioritize peer-reviewed journals, which undergo rigorous scrutiny by experts in the field before publication, ensuring the integrity of the research. Government publications, academic books, and reputable research databases contribute valuable insights and are recognized for their reliability. Additionally, consulting sources from professional associations, theses and dissertations, and conference proceedings provides a well-rounded perspective. It is essential to critically evaluate the credibility of grey literature, considering the source’s reputation and methodology. By meticulously curating a diverse array of high-quality sources, researchers can establish a robust foundation for their study, enhancing the validity and impact of their findings in the health and social science domains

A search strategy is a systematic plan or approach that researchers use to find relevant and credible literature on a specific topic during the literature review process. It involves a series of steps and techniques aimed at efficiently and comprehensively identifying scholarly sources that contribute to the understanding of the research question or topic of interest.

How to search for literature, finding evidence, literature review and research methods

Critical Evaluation of Literature

Critiquing a research study often involves a combination of these methods, with the choice depending on the nature of the study and the goals of the critique. The aim is to systematically evaluate the research’s credibility, reliability, and contribution to the existing body of knowledge. Critical appraisal can be challenging; let us first explore how to evaluate the sources from which the literature will be selected.    

When evaluating a source, it’s essential to go beyond a simple checklist, especially for unusual formats or document types. The three Cs—Compare, Corroborate, and Context—provide a comprehensive method for thorough evaluation.

  • Compare- The first step involves comparing the information with another source. Any differences detected prompt further investigation. Identifying inconsistencies at this stage sets the groundwork for a more nuanced evaluation.
  • Corroborate- The next step is to corroborate the information against multiple sources. While the Compare step involves one-on-one comparisons, Corroborate expands the scope, seeking consistency across various sources. This approach enhances the reliability of the information by establishing multiple points of reference.
  • Context- Contextualizing the information is the final step, considering factors such as the broader research field, mainstream theories, and ongoing debates. Understanding the context helps answer questions like: What is the prevailing understanding of the topic? Are there alternative theories or ongoing debates in the field? This step adds depth to the evaluation process.

The three Cs emphasize the importance of looking beyond individual pieces of information, encouraging researchers to situate sources within a broader context. Even if information can be corroborated across multiple sources, understanding the context is vital. For instance, corroborating studies may belong to a discredited school of thought or represent two equally valid perspectives. Additionally, there might be emerging research challenging mainstream theories, warranting further investigation. Other strategies for evaluating the source include: 

How to evaluate the source of literature, research methods, literature review.

The Reference List

Creating an accurate reference list is a crucial aspect of the literature review process. Various referencing systems dictate the format of your dissertation and reference list—common examples include APA, MLA, Harvard, Chicago styles, and others. The purpose of the reference list is to furnish essential details for identifying and locating the sources referenced in your research report. Only include sources actually used in the report, and ensure that each cited source appears in the reference list, and vice versa. It’s important to note that the reference list differs from a bibliography, focusing solely on sources cited in the report. Exclude personal communications like letters and memoranda, as well as informal electronic communication, from the reference list. Abiding by these guidelines ensures the accuracy and integrity of your academic citations.

Methods of Evaluation

Having evaluated the sources, the next step is to evaluate the research reports selected from our highest quality sources. Here are some common methods and approaches used to critique a research study:

1. Checklist or Guideline-Based Approach 

Utilizing a checklist or guideline provides a structured framework for assessment. It typically includes specific criteria related to the study’s title, abstract, introduction, methods, results, discussion, and conclusion. Researchers can follow a predetermined set of questions or statements to evaluate each section. A skilled reviewer assesses each research report unit by unit. This checklist or guideline-based approach is one of the easiest and most comprehensive methods of evaluation that can be used by students and professionals in research disciplines. Responses are sought for each of the following in this guideline-based approach:  

Title and Abstract- The title adequately describes the study, with concise and relevant keywords. The abstract effectively summarizes the study’s purpose, methods, and findings. It discloses the independent and dependent variables, providing a comprehensive overview.

Research Problem and Theoretical Rationale- The research problem is clearly identified, and its significance is addressed. The authors present a theoretical rationale, and the conceptual framework aligns logically with the research problem. Hypotheses and research questions are clearly stated and seem logical in the context of the study.

Literature Review and Method Section- The literature review logically leads into the Method section, providing a seamless transition. The sample is clearly described in terms of size, characteristics, selection, and procedures. The instruments are deemed appropriate, and their psychometric properties are sufficiently discussed. The study’s procedures are thoroughly described, and the design seems fitting.

Results Section- The results section is well-written and organized, with appropriate data coding and analysis in alignment with the study’s design and hypotheses. Salient results are connected to hypotheses, and tables/figures are appropriately labeled and organized.

Discussion and Conclusion- Limitations of the study are outlined, and findings are discussed in the context of the research problem, conceptual framework, and hypotheses. Implications for future research and practice are identified, and the general conclusions seem warranted in light of the results.

References and Overall Assessment- The reference list is sufficiently current, reflecting a breadth of existing literature. The article is well-written, organized, and addresses an important problem in the field. The study’s strengths are acknowledged, including clear articulation of variables and rigorous methodology. To improve, the study could benefit from potential enhancements in certain areas.

2. Critical Appraisal Tools

Critical appraisal tools are instruments used to systematically evaluate the quality, validity, and relevance of research studies. These tools are particularly valuable for researchers, clinicians, and decision-makers to assess the trustworthiness and reliability of published research. Different critical appraisal tools are tailored to specific study designs, recognizing the unique characteristics and requirements of various research methodologies. These tools typically consist of a set of criteria or questions that users answer based on the information provided in the research study. The goal is to offer a systematic and transparent approach to evaluating the strengths and weaknesses of research evidence, ultimately informing decisions about the applicability of study findings to practice or policy.

Examples of critical appraisal tools include:

Cochrane Risk of Bias Tool- Primarily designed for systematic reviews and meta-analyses, this tool assesses the risk of bias in randomized controlled trials (RCTs). It examines aspects such as random sequence generation, allocation concealment, blinding, incomplete outcome data, selective reporting, and other sources of bias.

Joanna Briggs Institute (JBI) Critical Appraisal Tools- JBI provides critical appraisal tools for various study types, including systematic reviews, case reports, and qualitative research. These tools guide users through a series of questions to evaluate different aspects of study quality.

Newcastle-Ottawa Scale (NOS)- This tool assesses the quality of non-randomized studies, such as cohort and case-control studies. It considers selection, comparability, and outcome assessment, assigning stars for each criterion to facilitate an overall quality assessment.

Appraisal of Guidelines for Research and Evaluation (AGREE) Instrument- Designed for evaluating clinical practice guidelines, the AGREE instrument assesses the rigor and transparency of guideline development, including stakeholder involvement, methodological quality, and clarity of presentation.

Critical Appraisal Skills Programme (CASP) Tools- CASP provides a series of tools for appraising various study designs, including systematic reviews, RCTs, case-control studies, and qualitative research. These tools offer structured questions to guide users in critically assessing different aspects of study validity.

Mixed Methods Appraisal Tool (MMAT)- MMAT is designed to appraise the methodological quality of mixed methods studies. It considers the qualitative, quantitative, and mixed methods components of a study.

Risk of Bias in Non-randomized Studies – of Interventions (ROBINS-I)- This tool is specifically tailored to assess the risk of bias in non-randomized intervention studies, providing a framework to evaluate confounding, selection bias, classification bias, and other sources of bias.

Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies- Developed by the National Heart, Lung, and Blood Institute, this tool assists in assessing the quality of observational cohort and cross-sectional studies.

3. GRADE (Grading of Recommendations Assessment, Development, and Evaluation)

GRADE is a widely used framework for evaluating the quality of evidence and determining the strength of recommendations in systematic reviews and meta-analyses. The GRADE approach provides a systematic and transparent process to assess the certainty of evidence, helping decision-makers interpret and use research findings effectively. Applying the GRADE framework, systematic reviewers and guideline developers can communicate the confidence in the evidence and the strength of recommendations, aiding healthcare professionals, policymakers, and patients in making informed decisions. The GRADE approach promotes transparency and consistency in evidence evaluation across different domains of healthcare.

How to use the GRADE evaluation tool
  1. Assessment of Evidence Quality

    • High (⊕⊕⊕⊕)- Very confident that the true effect lies close to that of the estimate.
    • Moderate (⊕⊕⊕◯)- Moderately confident in the effect estimate; the true effect is likely to be close to the estimate.
    • Low (⊕⊕◯◯)- Confidence in the effect estimate is limited; the true effect may be substantially different.
    • Very Low (⊕◯◯◯)- Very little confidence in the effect estimate; the true effect is likely to be substantially different.
  2. Factors Considered in Evidence Quality

    • Study Design– Randomized controlled trials (RCTs) start as high-quality evidence, while observational studies start as low-quality evidence.
    • Risk of Bias The extent to which bias may affect the results.
    • Inconsistency- The variability in results across studies.
    • Indirectness- How applicable the evidence is to the research question.
    • Imprecision- The degree of uncertainty around an effect estimate.
    • Publication Bias- The potential for selective reporting of outcomes.
  3. Determining the Strength of Recommendations

    • Strong Recommendation- The desirable effects of an intervention clearly outweigh any undesirable effects or vice versa.
    • Conditional (Weak) Recommendation- The balance between desirable and undesirable effects is less clear, and individual preferences, values, and circumstances may influence decision-making.
  4. Additional Considerations

    • GRADE encourages explicit consideration of values and preferences, costs, and feasibility when making recommendations.
Examples of how GRADE ratings are presented
  • “We recommend [intervention] for [population] due to high-quality evidence (⊕⊕⊕⊕).”
  • “We suggest [intervention] for [population] due to moderate-quality evidence (⊕⊕⊕◯).”

4. Other Methods of Evaluating Literature

CASP (Critical Appraisal Skills Programme)- CASP offers a set of tools designed for critiquing various types of research studies. These tools guide users through key questions to consider when appraising studies, helping to assess aspects like methodology, results, and applicability to practice.

Peer Review- Peer review involves having other researchers or experts in the field evaluate the study. This external review process can provide valuable insights and identify potential biases or weaknesses not immediately apparent to the original authors.

Quantitative and Qualitative Appraisal- Depending on the research design (quantitative or qualitative), different appraisal methods may be employed. For quantitative studies, considerations include the appropriateness of the study design, statistical methods, and generalizability. In qualitative studies, attention is given to aspects like reflexivity, credibility, and transferability.

Comparison with Standards and Guidelines- Researchers may critique a study by comparing it with established standards or guidelines in the field. This could include adherence to reporting guidelines like CONSORT (Consolidated Standards of Reporting Trials) for clinical trials or COREQ (Consolidated Criteria for Reporting Qualitative Research) for qualitative studies.

Utilizing Expert Opinions- Seeking the opinions of experts in the field can provide additional perspectives on the strengths and weaknesses of a study. Experts may offer insights into the methodology, relevance of the research question, and potential implications for practice.

Controversies, Gaps and Limitations

Critical appraisal of the work done by other professionals can be a challenging task, often accompanied by potential biases and personal preferences that may overshadow the critique, ultimately diminishing the quality and value of the appraisal. However, to enhance the rigor of this process, several guidelines and tools have been established. When documenting controversies, gaps, and limitations, researchers should use a combination of these tools and guidelines based on the type of study they are reviewing or conducting. These resources aim to assist researchers in systematically documenting controversies, identifying gaps, and recognizing limitations in prior research. Here are a few examples that offer structured frameworks for such evaluations.

PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses)

  • PRISMA provides a checklist and flow diagram for reporting systematic reviews and meta-analyses.
  • The PRISMA checklist includes items related to the discussion section, where researchers can address limitations and gaps in the existing literature.

CONSORT (Consolidated Standards of Reporting Trials)

  • CONSORT provides a guideline for reporting randomized controlled trials.
  • While CONSORT primarily focuses on trial reporting, the discussion section often includes considerations of limitations, controversies, and gaps in the trial design.

STROBE (Strengthening the Reporting of Observational Studies in Epidemiology):

  • STROBE offers a checklist for reporting observational studies.
  • Researchers can use the discussion section of the STROBE checklist to address limitations and suggest areas for future research.

CARE (CAse REport):

  • CARE provides guidelines for reporting case reports.
  • Though CARE focuses on case reports, researchers can discuss controversies or limitations related to the uniqueness of the reported case.

JBI (Joanna Briggs Institute) Critical Appraisal Tools

  • JBI offers critical appraisal tools for various study types.
  • The critical appraisal tools include sections for assessing the limitations and potential biases in each type of study.

Organizing the Literature Review

Organizing a literature review involves structuring the available literature in a way that effectively communicates the current state of knowledge on a specific topic. Maintain a clear and logical flow throughout the literature review, ensuring that each section contributes to the overall narrative. Consider the specific requirements of your assignment, research question, or intended audience when deciding on the most appropriate organizational structure.

The literature review report begins with an introduction, outlining the problem area, sub-areas to be covered, and main questions. In the main body, a comprehensive synthesis of referenced material is presented, avoiding reliance on a limited set of sources. Sub-headings are used to organize information and maintain focus, while insights into aspects of the topic that require exploration are provided. The report is fair, objective, and evidence-based, evaluating various perspectives and exemplary studies. The conclusion highlights gaps and limitations in existing research, critiques methodologies, and explains how the literature review refines the research subtopic, connecting the study to the reviewed literature. The emphasis throughout is on logical persuasion and evidence rather than emotive language.

Introduction

  • Provide a brief overview of the research topic.
  • Define the scope and purpose of the literature review.
  • Highlight the key themes, issues, or controversies in the field.
  1. Subheadings and Subsections

    • Use clear subheadings to delineate different sections of the literature.
    • Create subsections under each heading to further categorize and organize studies.
  2. Compare and Contrast

    • Compare and contrast findings across studies.
    • Identify common trends or areas of divergence.
    • Discuss how various studies contribute to the overall understanding of the topic.
  3. Critical Evaluation

    • Offer critical assessments of individual studies.
    • Discuss the strengths, weaknesses, and limitations of each source.
    • Evaluate the overall quality of the existing literature.
  4. Synthesis and Integration

    • Synthesize information from different studies to form overarching conclusions.
    • Discuss how the literature contributes to addressing gaps or answering research questions.
    • Integrate findings to propose directions for future research.

You should maintain a clear and logical flow throughout the literature review, ensuring that each section contributes to the overall narrative. Let us explore some formats to help with this evaluation and layout:

The research theme refers to the overarching topic or subject of interest that the research study aims to explore, understand, or contribute new knowledge to. It represents the central idea or focus around which the entire research project revolves. Articulating the research theme in the literature review involves clearly defining and contextualizing the chosen topic within the existing body of literature. This includes providing a clear and concise statement of the topic, issue, or phenomenon under investigation. As the reviewer, you strategically place the research theme within the context of existing literature. This involves summarizing key studies, theories, and models related to the theme. It helps establish the background and significance of the chosen topic.

Thematic organization of research reports, Literature review, Research methodsRecall this Research Title from Chapter One:

“A cross-sectional analysis of urban obesity: Investigating the Impact of Access to Nutritious Food and Physical Activity Opportunities on Obesity Rates among Adults (18-65) in Low-Income Neighborhoods of Kingston and St. Andrew.”

Exploring these themes, (Physical Activities Opportunities, Access to Nutritious Foods, and Urban Obesity) the research aims to contribute valuable insights into the complex interplay of environmental, social, and individual factors influencing obesity rates in urban low-income neighborhoods.

Each theme represents a critical aspect of the broader research topic, allowing for comprehensive analysis of multiple factors contributing to urban obesity in the specified demographic and urban geographical context.

A Guide for Thematic Organization
  • Group studies and sources based on common themes or topics. Example, studies discussing “Availability and Accessibility of Recreational Facilities” should be grouped together and discussed as a sub-theme under “Physical Activities Opportunities.”  
  • Identify key concepts or variables relevant to the research. For example socio-economic context of the neighbourhood, prevalence of obesity in urban neighbourhoods, affordability of nutritious foods, etc. 
  • Discuss studies within each theme, noting similarities and differences.
 
When organizing a literature review chronologically, it’s essential to follow a structured approach that emphasizes the progression of research over time. Here are additional guidelines for effectively implementing a chronological organization:
  1. Identify Key Time Periods- Divide the literature into key time periods based on significant shifts, developments, or milestones in the research field. This helps in creating a clear structure for your review.

  2. Establish a Historical Context- Provide a brief overview of the historical context for each time period. Highlight major events, changes in societal attitudes, or shifts in policy that might have influenced research trends during those periods.

  3. Trace Methodological Changes- Explore how research methodologies have evolved over time. Identify changes in data collection methods, study designs, or analytical approaches. Discussing these changes contributes to a nuanced understanding of the field’s development.

  4. Highlight Landmark Studies- Emphasize landmark or seminal studies within each time period. These studies could have significantly impacted the direction of research or introduced key theories and concepts.

  5. Discuss Paradigm Shifts- Address any paradigm shifts in the research field. Identify moments when new theoretical frameworks emerged or when there was a departure from traditional perspectives. Discuss how these shifts influenced subsequent research.

  6. Draw Connections Between Studies- Establish connections between studies across different time periods. Discuss how earlier research laid the groundwork for subsequent investigations or how findings from different eras relate to each other.

  7. Identify Consistent Themes- Despite chronological changes, there may be consistent themes or patterns in the literature. Identify these recurring themes and discuss how they have persisted or evolved over time.

  8. Evaluate Progression in Understanding- Evaluate how the understanding of the research problem has progressed over the years. Highlight any advancements in knowledge, emerging trends, or unresolved questions that persist across different time periods.

  9. Consideration of Contextual Factors- Reflect on external factors such as technological advancements, societal changes, or policy shifts that may have influenced the trajectory of research. Understanding the broader context enhances the depth of your review.

  10. Provide Insight into Future Directions- Conclude your review by discussing the current state of the field and potential future directions. Consider how recent studies build upon or challenge earlier research, and identify gaps that need further exploration.

A chronological organization of literature may not be the most suitable approach for the research topic we have been exploring throughout this chapter. We will explore another example, applying chronological analysis to the review of literatures. 

Chronological organization of research reports in the literature review, Research methods. Example Research Title:

Evolution of Antiretroviral Therapy Strategies in Managing HIV/AIDS.”

A chronological organization of the literature review allows for tracing the historical development and evolution of antiretroviral therapy (ART) strategies in the management of HIV/AIDS over time.

  • Using this approach, readers gain a historical context, understanding the sequential development of ART strategies.
  • The review highlights patterns of evolution, identifying critical turning points in the management of HIV/AIDS.
  • It provides a cohesive narrative of how treatment approaches have changed over time.

By adopting a chronological organization, the literature review becomes a journey through the history of HIV/AIDS treatment, offering insights into the evolution of ART strategies and their impact on the management of the disease.

By incorporating these additional considerations, your chronologically organized literature review will not only showcase the temporal evolution of research but also provide a comprehensive analysis of the field’s development, allowing readers to grasp the changing landscape and trends over time

Methodological Organization of the Literature Review

Methodological organization in a literature review involves structuring the review based on the research methods employed in the selected studies. This approach allows for a focused examination of the methodologies used in various research articles, providing insights into the strengths and limitations of different approaches. Additionally, it enables the identification of trends or patterns in the utilization of specific research methods within a given field. 

Methodological organization offers several advantages in structuring a literature review. Firstly, it allows for a focused analysis by providing a concentrated examination of various research methods. This focused approach aids in developing an in-depth understanding of how these methods contribute to the existing body of literature. Secondly, the methodological organization facilitates critical evaluation. It enables the reviewer to critically assess the strengths and weaknesses inherent in different methodologies employed across studies. This critical evaluation contributes to the understanding of the reliability and validity of research findings. This organizational approach plays a vital role in informing research design. By identifying trends in the literature regarding the use of specific research methods, it provides valuable insights for researchers in choosing appropriate methodologies for their own studies. In essence, methodological organization enhances the literature review by promoting focused analysis, critical evaluation, and guiding future research endeavors.

Organization by Theoretical Framework, Research Theories, or Models

An alternative method for structuring the literature review involves applying a research theory or model to the examined research reports. This entails organizing the studies according to the theoretical frameworks they employ. The reviewer explores how distinct theories enhance comprehension of the research problem. It is imperative to conduct a critical analysis of the implications associated with applying specific theories as well.

Recall this Research Title from Chapter One:

“A cross-sectional analysis of urban obesity: Investigating the Impact of Access to Nutritious Food and Physical Activity Opportunities on Obesity Rates among Adults (18-65) in Low-Income Neighborhoods of Kingston and St. Andrew.”

We will apply the HBM and SEM, to the literature review to offer a structured and comprehensive examination of how these theoretical frameworks have been utilized in previous research to investigate the impact of access to nutritious food and physical activity opportunities on obesity rates in urban, low-income neighborhoods. This approach ensures a thorough exploration of individual beliefs, societal influences, and environmental factors that contribute to the complex issue of urban obesity.

Health Belief Model (HBM)

Organizing around HBM Constructs

Structure the literature review based on key constructs of the HBM, such as perceived susceptibility, severity, benefits, and barriers. Explore how these factors have been addressed in the literature concerning access to nutritious food and physical activity opportunities in low-income neighborhoods.

Application of HBM in Intervention Studies

Highlight studies that have applied the HBM in designing interventions to improve health behaviors related to nutrition and physical activity. Discuss how these interventions have impacted obesity rates in urban settings.

Social Ecological Model (SEM)

Levels of Influence

Organize the literature according to the levels of influence in the SEM, including individual, interpersonal, community, and societal factors. Examine how various studies have considered these levels in understanding and addressing obesity in urban areas.

Environmental and Policy Factors

Explore literature that specifically addresses environmental and policy factors influencing access to nutritious food and opportunities for physical activity in urban settings. Discuss how these factors contribute to or mitigate obesity rates among adults.

Concluding the Literature Review

  • Summarize the key findings and insights from the literature review.
  • Emphasize the contributions of the reviewed studies to the research field.
  • Provide recommendations for future research based on the gaps identified.

Summary

The literature review is a critical element in research, serving multiple crucial purposes. It acts as a foundation, allowing researchers to gain an in-depth understanding of existing scholarly works in their field, highlighting the current state of knowledge.

This exploration helps identify gaps and unresolved issues, guiding the formulation of focused research questions and objectives. The evaluation is designed to address specific gaps in existing knowledge, making a meaningful contribution to the field.

Literature reviews assist researchers in making informed decisions about data collection methods by evaluating the strengths and weaknesses of approaches used in previous studies. This ensures that the chosen methods are suitable, leading to reliable and relevant data collection aligned with the research questions.

In summary, the literature review not only provides a comprehensive overview of existing knowledge but also plays a pivotal role in shaping research questions and guiding the selection of appropriate data collection methods, contributing to relevant and impactful studies within the field.

Health Science Research Methods

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Chapter One- Introduction

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Chapter Three- Research Design and Methodology

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Chapter Four- Data Analysis and Results

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References

Creswell, J. W. (2017). Research design: Qualitative, quantitative, and mixed methods approaches (4th ed.). SAGE Publications.

Doyle, A. (2017) Critical Thinking Skills List and Examples. https://www.thebalance.com/critical-thinking-definition-with-examples-2063745

Leedy, P.D. and Ormrod, J.E. (2005) Practical Research: Planning and Design. Prentice Hall, Upper Saddle River, NJ. http://www.worldcat.org/title/practical-research-planning-and-design/oclc/53831701.

Pearce, N. (2012) Classification of Epidemiological Study Designs. International Journal of Epidemiology 2012(41) 393–397
doi:10.1093/ije/dys049

Author: D. L. Baker (BPharm, MBA, MPH, Dip.Ed.)

Published: 2024- Feb- 9; Last updated: 2024- Feb- 15