How To Use Literature Review In Research

The need for comprehensive literature searches is less certain in reviews of qualitative studies, and for reviews where a comprehensive identification of studies is difficult to achieve . Different approaches to literature searching and developing the concept of when to stop searching are important areas for further study . The need for thorough and comprehensive literature searches appears as uniform within the eight guidance documents that describe approaches to literature searching in systematic reviews of effectiveness. Reviews of effectiveness , accuracy and prognosis, require thorough and comprehensive literature searches to transparently produce a reliable estimate of intervention effect.

The belief that all relevant studies have been 'comprehensively' identified, and that this process has been 'transparently' reported, increases confidence in the estimate of effect and the conclusions that can be drawn . The supporting literature exploring the need for comprehensive literature searches focuses almost exclusively on reviews of intervention effectiveness and meta-analysis. Different 'styles' of review may have different standards however; the alternative, offered by purposive sampling, has been suggested in the specific context of qualitative evidence syntheses .

The average number of bibliographic database searched in systematic reviews has risen in the period 1994– but there remains no consensus on what constitutes an acceptable number of databases searched . This is perhaps because thinking about the number of databases searched is the wrong question, researchers should be focused on which databases were searched and why, and which databases were not searched and why. The discussion should re-orientate to the differential value of sources but researchers need to think about how to report this in studies to allow findings to be generalised. Bethel has proposed 'search summaries', completed by the literature searcher, to record where included studies were identified, whether from database or supplementary search methods .

Search summaries document both yield and accuracy of searches, which could prospectively inform resource use and decisions to search or not to search specific databases in topic areas. The prospective use of such data presupposes, however, that past searches are a potential predictor of future search performance (i.e. that each topic is to be considered representative and not unique). In offering a body of practice, this data would be of greater practicable use than current studies which are considered as little more than individual case studies . This review calls for further research to determine the suitability of using the conventional approach.

The publication dates of the guidance documents which underpin the conventional approach may raise questions as to whether the process which they each report remains valid for current systematic literature searching. Defining the key stages in this review helps categorise the scholarship available, and it prioritises areas for development or further study. The supporting studies on preparing for literature searching (key stage three, 'preparation') were, for example, comparatively few, and yet this key stage represents a decisive moment in literature searching for systematic reviews. It is where search strategy structure is determined, search terms are chosen or discarded, and the resources to be searched are selected.

Information specialists, librarians and researchers, are well placed to develop these and other areas within the key stages we identify. Egger et al., and other study authors, have demonstrated a change in the estimate of intervention effectiveness where relevant studies were excluded from meta-analysis . This would suggest that missing studies in literature searching alters the reliability of effectiveness estimates. You will read about 10 articles in detail, a few times more than that you will skim the abstract, introduction, and conclusion, but you will ultimately never read everything. Make the most out of the articles you do read by extracting as many facts as possible from each.

This way, by reading only a small number of articles, you are also reading their citations and synthesis of dozens of other articles as well. Reporting of literature searching is a key area in systematic reviews since it sets out clearly what was done and how the conclusions of the review can be believed . Despite strong endorsement in the guidance documents, specifically supported in PRISMA guidance, and other related reporting standards too , authors still highlight the prevalence of poor standards of literature search reporting . Atkinson et al. have also analysed reporting standards for literature searching, summarising recommendations and gaps for reporting search strategies .

From the guidance, we determined eight key stages that relate specifically to literature searching in systematic reviews. Table 2 reports the areas of common agreement and it demonstrates that the language used to describe key stages and processes varies significantly between guidance documents. A literature review is an overview of the previously published works on a specific topic. The term can refer to a full scholarly paper or a section of a scholarly work such as a book, or an article. Either way, a literature review is supposed to provide the researcher/author and the audiences with a general image of the existing knowledge on the topic under question. A good literature review can ensure that a proper research question has been asked and a proper theoretical framework and/or research methodology have been chosen.

To be precise, a literature review serves to situate the current study within the body of the relevant literature and to provide context for the reader. In such case, the review usually precedes the methodology and results sections of the work. Literature reviews are designed to provide an overview of sources you have explored while researching a particular topic and to demonstrate to your readers how your research fits within a larger field of study. The findings reported above reveal eight key stages in the process of literature searching for systematic reviews. These key stages are consistently reported in the nine guidance documents which suggests consensus on the key stages of literature searching, and therefore the process of literature searching as a whole, in systematic reviews.

Table 2 also summaries the process of literature searching which follows bibliographic database searching. As Table 2 sets out, guidance that supplementary literature search methods should be used in systematic reviews recurs across documents, but the order in which these methods are used, and the extent to which they are used, varies. We noted inconsistency in the labelling of supplementary search methods between guidance documents. When to database search is another question posed in the literature. Beyer et al. report that databases can be prioritised for literature searching which, whilst not addressing the question of which databases to search, may at least bring clarity as to which databases to search first . Paradoxically, this links to studies that suggest PubMed should be searched in addition to MEDLINE since this improves the currency of systematic reviews .

Cooper et al. have tested the idea of database searching not as a primary search method but as a supplementary search method in order to manage the volume of studies identified for an environmental effectiveness systematic review. Their case study compared the effectiveness of database searching versus a protocol using supplementary search methods and found that the latter identified more relevant studies for review than searching bibliographic databases . Eight documents provided guidance on who should undertake literature searching in systematic reviews . The guidance affirms that people with relevant expertise of literature searching should 'ideally' be included within the review team . Information specialists , librarians or trial search co-ordinators are indicated as appropriate researchers in six guidance documents .

Eight key stages to the process of literature searching in systematic reviews were identified. These key stages are consistently reported in the nine guidance documents, suggesting consensus on the key stages of literature searching, and therefore the process of literature searching as a whole, in systematic reviews. Further research to determine the suitability of using the same process of literature searching for all types of systematic review is indicated. Using the annotations in Section 4.2 as a guide, create a spreadsheet or Word table with your annotation categories as columns and each source as new row. For example, I was searching for articles on using a specific educational technique in the literature. I wanted to know whether other researchers found positive results, how big their samples were, and whether they were conducted at a single school or across multiple schools.

I looked through each empirical article on the topic and filled in a summary table. At the end, I could do an easy visual analysis and state that most studies revealed no significant results and that there were few multi-site studies. These tables are similar to those you will find in a systematic review article. What is not clear is the extent to which the guidance documents inter-relate or provide guidance uniquely. The Cochrane Handbook, first published in 1994, is notably a key source of reference in guidance and systematic reviews beyond Cochrane reviews. Since we cannot be clear, we raise this as a potential limitation of this literature review.

On our initial review of a sample of North American, and other, guidance documents , however, we do not consider that the inclusion of these further handbooks would alter significantly the findings of this literature review. The purpose of thorough and comprehensive literature searches is to avoid missing key studies and to minimize bias since a systematic review based only on published studies may have an exaggerated effect size . Felson sets out potential biases that could affect the estimate of effect in a meta-analysis and Tricco et al. summarize the evidence concerning bias and confounding in systematic reviews . Egger et al. point to non-publication of studies, publication bias, language bias and MEDLINE bias, as key biases . Comprehensive searches are not the sole factor to mitigate these biases but their contribution is thought to be significant .

Fehrmann suggests that 'the search process being described in detail' and that, where standard comprehensive search techniques have been applied, increases confidence in the search results . We were able to identify consensus across the guidance on literature searching for systematic reviews suggesting a shared implicit model within the information retrieval community. Whilst the structure of the guidance varies between documents, the same key stages are reported, even where the core focus of each document is different.

We were able to identify specific areas of unique guidance, where a document reported guidance not summarised in other documents, together with areas of consensus across guidance. Once a list of key guidance documents was determined, it was checked by six senior information professionals based in the UK for relevance to current literature searching in systematic reviews. The first step in your research is to determine the specific question, topic or problem that your literature review will focus on (if a topic or question hasn't been provided to you by your lecturer or tutor). This will help you undertake relevant keyword searches in the databases available through your university's library or other appropriate sources. You can also use the reference lists in your course readings to locate relevant source material.

Literature refers to a collection of published information/materials on a particular area of research or topic, such as books and journal articles of academic value. However, your literature review does not need to be inclusive of every article and book that has been written on your topic because that will be too broad. Rather, it should include the key sources highlighting the main debates, trends and gaps in your specific research area. Knowledge production within the field of business research is accelerating at a tremendous speed while at the same time remaining fragmented and interdisciplinary. This makes it hard to keep up with state-of-the-art and to be at the forefront of research, as well as to assess the collective evidence in a particular area of business research.

This is why the literature review as a research method is more relevant than ever. Traditional literature reviews often lack thoroughness and rigor and are conducted ad hoc, rather than following a specific methodology. Therefore, questions can be raised about the quality and trustworthiness of these types of reviews. This paper discusses literature review as a methodology for conducting research and offers an overview of different types of reviews, as well as some guidelines to how to both conduct and evaluate a literature review paper. It also discusses common pitfalls and how to get literature reviews published. This literature review would appear to demonstrate the existence of a shared model of the literature searching process in systematic reviews.

We call this model 'the conventional approach', since it appears to be common convention in nine different guidance documents. How the reporting of the literature searching process corresponds to critical appraisal tools is an area for further research. In the survey undertaken by Radar et al. , 86% of survey respondents (153/178) identified a need for further guidance on what aspects of the literature search process to report . The PRISMA statement offers a brief summary of what to report but little practical guidance on how to report it . The purpose of sources and references is to provide valuable information. Use relevant keywords, and find credible academic references that add value to your research paper and strengthen your position.

Read and evaluate them to understand assumptions made by other researchers, in addition to the methodologies used. Highlight the names of notable experts in your field and list all conflicting opinions in your literature review. Finding models of other literature reviews is essential as it helps you see how others handled similar tasks. Literature reviews can have different types of audiences, so consider why and for whom you are writing your review.

For example, a lot of literature reviews are written as a chapter for a thesis or dissertation, so the audience will want to know in what way your research is important and original. Highlighting the gap in knowledge which your research aims to fill is particularly important in this instance because you need to convince the reader that there is an opening in the area of study. A literature review in a proposal will similarly try to convince the audience of the significance and worthiness of the proposed project. In contrast, when you are writing a literature review for a course, your professor may want you to show that you understand what research has been done, giving you a base of knowledge. In this case, you may not need to focus as much on proving where the gaps in knowledge lie, but rather, that you know what the major areas of study and key ideas are.

A systematic literature review identifies, selects and critically appraises research in order to answer a clearly formulated question (Dewey, A. & Drahota, A. 2016). The systematic review should follow a clearly defined protocol or plan where the criteria is clearly stated before the review is conducted. It is a comprehensive, transparent search conducted over multiple databases and grey literature that can be replicated and reproduced by other researchers.

It involves planning a well thought out search strategy which has a specific focus or answers a defined question. The review identifies the type of information searched, critiqued and reported within known timeframes. The search terms, search strategies and limits all need to be included in the review.

The literature review is a written overview of major writings and other sources on a selected topic. Sources covered in the review may include scholarly journal articles, books, government reports, Web sites, etc. The literature review provides a description, summary and evaluation of each source. It is usually presented as a distinct section of a graduate thesis or dissertation.

Developing a concept map or mind map around your topic can be helpful in figuring out how the facts fit together. We talked about concept mapping briefly in Chapter 2, when we were first thinking about your topic and sketching out what you already know about it. Concept mapping during the literature review stage of a research project builds on this foundation of knowledge and aims to improve the "description of the breadth and depth of literature in a domain of inquiry. Its purpose, like other question refinement methods, is to help you organize, prioritize, and integrate material into a workable research area – one that is interesting, answerable, feasible, objective, scholarly, original, and clear. Over the past few years, numerous studies and research articles have been published in the medical literature review domain.

The topics covered by these researches included medical information retrieval, disease statistics, drug analysis, and many other fields and application domains. In this paper, we employ various text mining and data analysis techniques in an attempt to discover trending topics and topic concordance in the healthcare literature and data mining field. This analysis focuses on healthcare literature and bibliometric data and word association rules applied to 1945 research articles that had been published between the years 2006 and 2019. Our aim in this context is to assist saving time and effort required for manually summarizing large-scale amounts of information in such a broad and multidisciplinary domain. To carry out this task, we employ topic modeling techniques through the utilization of Latent Dirichlet Allocation , in addition to various document and word embedding and clustering approaches.

Findings reveal that since 2010 the interest in the healthcare big data analysis has increased significantly, as demonstrated by the five most commonly used topics in this domain. This research was conducted with literature review methodfollow Cronin's theory (Cronin et al., 2008). In Table 2, we demonstrate consensus regarding the application of literature search methods.

All guidance documents distinguish between primary and supplementary search methods. Bibliographic database searching is consistently the first method of literature searching referenced in each guidance document. Whilst the guidance uniformly supports the use of supplementary search methods, there is little evidence for a consistent process with diverse guidance across documents. This may reflect differences in the core focus across each document, linked to differences in identifying effectiveness studies or qualitative studies, for instance. The guidance documents summarise 'how to' search bibliographic databases in detail and this guidance is further contextualised above in terms of developing the search strategy.

The host of the database (e.g. OVID or ProQuest) has been shown to alter the search returns offered. Younger and Boddy report differing search returns from the same database but where the 'host' was different . The chapter or section sub-heading for each methodological stage was extracted into a table using the exact language as reported in each guidance document. The lead author then read and re-read these data, and the paragraphs of the document to which the headings referred, summarising section details.

This table was then reviewed, using comparison and contrast to identify agreements and areas of unique guidance. Consensus across multiple guidelines was used to inform selection of 'key stages' in the process of literature searching. The relevant sections within each guidance document were then read and re-read, with the aim of determining key methodological stages.