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Marine & Freshwater Ecology: Reviews

what is

A systematic review (also systematic literature review or structured literature review, SLR) is a review of literature focused on a research question that tries to identify, appraise, select and synthesize all high quality research evidence relevant to that question. Systematic reviews of high-quality randomized controlled trials are crucial to evidence-based medicine.
An understanding of systematic reviews and how to implement them in practice is becoming mandatory for all professionals involved in the delivery of health care. Systematic reviews are not limited to medicine and are quite common in all other sciences where data are collected, published in the literature, and an assessment of methodological quality for a precisely defined subject would be helpful.

Literature and Systematic Review Resources

Annual Reviews
Annual Reviews critically reviews the most significant primary research literature to guide researchers to the principal contributions of their field and help them keep up to date in their area of research. Each article is its own search engine, provides a gateway to the essential primary research literature referenced within each topic.

BIOSIS Previews
Citations for journal articles, conference papers, and books on a wide variety of biological and biomedical topics.
Indexes journals, books, and conference proceedings are indexed on a wide variety of biological and biomedical topics.
Coverage: 1926 - present

Cochrane Library
A collection of six databases that contain different types of high-quality, independent evidence to inform healthcare decision-making.
Indexes journal articles, reviews, and bibliographies which provide evidence-based effects of health care, and a register of published economic evaluations of health care interventions and information on healthcare technology assessment from databases such as The Cochrane Database of Systematic Reviews, Controlled Trials Register, and the Database of Abstracts of Reviews of Effectiveness.
Coverage:  date varies | Some full text |

Embase
Search for biomedical literature citations. Embase is a key resource for conducting systematic reviews and researching evidence-based medicine. Indexes journals, including many not in Medline and indexes conference abstracts. Broad biomedical scope with strong coverage in drug, pharmaceutical, and toxicological research including economic evaluation.
Coverage: dates vary

Components

1. Introduction

Not to be confused with a book review, a literature review surveys scholarly articles, books and other sources (e.g. dissertations, conference proceedings) relevant to a particular issue, area of research, or theory, providing a description, summary, and critical evaluation of each work. The purpose is to offer an overview of significant literature published on a topic.

2. Components

Similar to primary research, development of the literature review requires four stages:

  • Problem formulation—which topic or field is being examined and what are its component issues?
  • Literature search—finding materials relevant to the subject being explored
  • Data evaluation—determining which literature makes a significant contribution to the understanding of the topic
  • Analysis and interpretation—discussing the findings and conclusions of pertinent literature

Literature reviews should comprise the following elements:

  • An overview of the subject, issue or theory under consideration, along with the objectives of the literature review
  • Division of works under review into categories (e.g. those in support of a particular position, those against, and those offering alternative theses entirely)
  • Explanation of how each work is similar to and how it varies from the others
  • Conclusions as to which pieces are best considered in their argument, are most convincing of their opinions, and make the greatest contribution to the understanding and development of their area of research

In assessing each piece, consideration should be given to:

  • Provenance—What are the author's credentials? Are the author's arguments supported by evidence (e.g. primary historical material, case studies, narratives, statistics, recent scientific findings)?
  • Objectivity—Is the author's perspective even-handed or prejudicial? Is contrary data considered or is certain pertinent information ignored to prove the author's point?
  • Persuasiveness—Which of the author's theses are most/least convincing?
  • Value—Are the author's arguments and conclusions convincing? Does the work ultimately contribute in any significant way to an understanding of the subject?

3. Definition and Use/Purpose

A literature review may constitute an essential chapter of a thesis or dissertation, or may be a self-contained review of writings on a subject. In either case, its purpose is to:

  • Place each work in the context of its contribution to the understanding of the subject under review
  • Describe the relationship of each work to the others under consideration
  • Identify new ways to interpret, and shed light on any gaps in, previous research
  • Resolve conflicts amongst seemingly contradictory previous studies
  • Identify areas of prior scholarship to prevent duplication of effort
  • Point the way forward for further research
  • Place one's original work (in the case of theses or dissertations) in the context of existing literature

The literature review itself, however, does not present new primary scholarship.

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