The Literature Review in the Masters Dissertation. Roberta Sammut

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1 The Literature Review in the Masters Dissertation Roberta Sammut

2 If I have seen further it is by standing on the shoulders of giants Isaac Newton

3 Why are reviews needed Research information is like small jigsaw puzzle pieces in a box, where there are several pictures, several duplicates and several missing pieces (Sheldon 1998) Individual studies use different methods, are of different quality and may present contradictory findings We cannot give too much importance to one individual study

4 Why do you need to carry out a literature review? Needed for identifying: Areas of uncertainty Where reality may be different to what is believed Where more research is needed How research in the area has been carried out strengths and limitations The main theories and issues on your topic and critique of these

5 What distinguishes a good quality literature review? Appropriate breadth and depth Rigour and consistency Clarity and brevity Effective analysis and synthesis Use of the literature to justify: The particular approach to the topic The selection of methods That your research contributes something new

6 Changing expectations at a postgraduate level (Hart 2007) What is expected of a literature review at undergraduate level Familiarity with a topic Skills to be able to carry out a search on the subject Knowledge on appropriate referencing style and an ability to create accurate bibliography The ability to summarise key ideas and some critical awareness

7 Changing expectations at a postgraduate level (Hart 2007) The content of the literature review at undergraduate level Descriptive and focused on the topic Includes the main current papers on the topic Analyses the papers on the topic in terms of different arguments presented and different results

8 The expectations at Masters level (Hart 2007) An increase in the scope, breadth and depth of the literature search Application of relevant literature from across other disciplines Competence in reading research

9 The literature review of the Masters dissertation (Hart 2007) The literature review is a major component of your dissertation Analytical evaluating current ideas on the topic Summative providing a comprehensive overview of what is known, what the gaps are Covers methodological issues in relation to different research techniques Includes discussion of theoretical issues relevant to the study

10 Your literature review in context Your thesis must form a coherent whole Your literature review should be clearly linked to: Your justification for carrying out the study Your aims and objectives Your choice of research design The methods used to collect data Your discussion of the results Your conclusions and recommendations

11 Starting out: what type of review is appropriate to your work? Traditional Review (Gough 2004) Journalistic Review (Greenhalgh 1997) Narrative Review (Macdonald 2003) Usually broader in focus Do not address specific question Not necessarily comprehensive in literature included Do not state reasons for inclusion of papers Not structured in approach to searching for literature and evaluation of quality Systematic Review the shift in emphasis from the art of writing a review to the science of reviewing the evidence (Milne and Chambers 1993)

12 Famous example of possible different outcomes for systematic vs. traditional reviews (Petticrew and Roberts 2006) Linus Pauling (1974) Well-known physician and Nobel prize laureate Carried out review on effect of Vitamin C on prevention of colds Conclusions: High dose of Vit C prevents colds People should consume 100 times dose of Vitamin C than currently being consumed

13 Famous example of possible different outcomes for systematic vs. traditional reviews (Petticrew and Roberts 2006) Douglas et al (2004) Systematic review of papers published during the time of Pauling s review Conclusions: High doses of Vitamin C do not prevent colds Can reduce the duration of the cold by a few days Pauling did not include 15 relevant articles

14 What is a systematic review? A review of research literature using systematic and explicit, accountable methods (Gough 2012) The key characteristics of a systematic review are: Rigor: use of systematic methods to answer set research question Transparency: every step is described; nothing left to reader s imagination Replicability: a second researcher should arrive at the same conclusions (Oakley 2012)

15 Features of systematic reviews: Rigor (Oakley 2012) The methods used are designed to ensure rigor in the process being used and are predetermined Comprehensiveness in the search used to avoid excluding relevant research e.g. grey literature which could lead to publication bias Specific criteria for the inclusion or exclusion of studies to avoid leaving out unfavourable results Use of more than one researcher to search literature, decide on inclusion and exclusion of studies, appraise studies Conclusions are based on the most rigorous studies

16 Diversity of systematic reviews A systematic review is a secondary research study Questions and methods used in systematic reviews reflect those of the primary research studies Share the same theoretical assumptions Share the same approach

17 One species; many breeds Systematic reviews may differ on the basis of the: Nature of the research question (Oakley 2012) What we want to find out: What works What people want What people consider to be appropriate The breadth and depth of the research question E.g. What is known about the barriers to and facilitators of healthy eating and physical activity in young people? vs. Is CBT more effective than Health Education in producing weight loss in young people between 14 and 16 years of age?

18 The key steps of a systematic review (Gough 2012) Review initiation: Formation of review team; engagement of stakeholders Preparation of a protocol: review question, conceptual framework and methodology Search strategy: search and screen literature on the basis of eligibility criteria Mapping: identifying and describing relevant research papers Appraising: critically critiquing the research papers using systematic methods (quality appraisal criteria) Synthesis: Putting together the results of the review into a coherent whole, creating something new (using conceptual framework and quality judgements) Using reviews (interpret and communicate findings with stakeholders) All decisions/methods used are explained and justified

19 Step 1: develop a review question Clearly identify your review question PICO framework: Population (P), Intervention (I) or Exposure (E), Comparison (C), Outcomes (O), Time (T) SPICE framework: Setting where? Perspective for whom? Intervention what? Comparison compared with what? Evaluation with what result?

20 Step 2: Develop a search strategy Identify the relevant databases: e.g. CINAHL, MedLine, PsychInfo, AgeLine etc. Consider the advantages/disadvantages of running combined searches Identify the keywords which you should use to access relevant research papers use thesaurus, MeSH terms Plan out Boolean phrases, truncation and wild cards Identify any limiters to your search with justification

21 Step 3: Develop inclusion/exclusion criteria Your review should not include every possible paper on your topic The papers you include should be directly relevant Develop inclusion/exclusion criteria on the basis of your review question

22 Step 4: Develop review management tools Keep track of what you are doing on a daily basis: use a diary Use bibliographic software/files on databases/excel sheets to keep track of articles you exclude with reasons for exclusion Develop an information extraction sheet to consistently extract the same type of data from each paper

23 Step 5: Use the PRISMA flowchart PRISMA 2009 Flow Diagram Included Eligibility Screening Identification Records identified through database searching (n = ) Records after duplicates removed (n = ) Records screened (n = ) Full-text articles assessed for eligibility (n = ) Studies included in qualitative synthesis (n = ) Studies included in quantitative synthesis (meta-analysis) (n = ) Additional records identified through other sources (n = ) Records excluded (n = ) Full-text articles excluded, with reasons (n = )

24 Step 6: Appraise your studies Weight of evidence framework (Gough 2007). Three dimensions: Quality of execution of the study soundness Appropriateness of the study design and analysis for addressing the review question How well matched the study is to the focus of the review

25 Step 6: Appraise your studies Use a Checklist or scale to systematically examine main methodological aspects of each study Less likely that methodological problems will be missed More than one checklist may be needed if mixed methods are used Multitude of appraisal tools available: Downs and Black randomized and nonrandomized studies Cowley comparative studies Newcastle-Ottawa Scale nonrandomised studies Critical Appraisal Skills Programme There may not be a suitable checklist available you may need to adapt a checklist or develop a new one

26 Step 7: Decide on how you are going to use the information from the appraisal As a threshold to include/exclude studies Weight the studies qualitatively, when summarizing the results e.g. high, intermediate, low quality Weight the studies quantitatively - low scoring studies contribute less to the final summary effect size estimate Describe the quality and relevance of each study for the reader to arrive at own conclusions Carry out a sensitivity analysis effect of including/excluding studies of lower quality on the results Recommendations for future research in terms of methods

27 Step 7: Writing up Prepare a plan of your review Introduction History of the topic including assumptions and definitions from other researchers Theoretical background Address each of your research objectives by summarising research Conclusion

28 Questions to ask yourself when writing up (Hart 2007, p. 14) What are the key sources? What are the key theories, concepts and ideas? What are the epistemologica l and ontological grounds for the discipline? What are the major issues and debates about the topic? Literature search and review on your topic What are the main questions and problems that have been addressed to date? How have approaches to these questions increased our understanding and knowledge? What are the political standpoints? What are the origins and definitions of the topic? How is knowledge on the topic structured and organised?

29 In summary: key issues for success Perseverance and diligence! Justification for the topic of your research and your choice of approach Avoid communicating personal opinions and views and don t present facts without sufficient evidence Learn how to reference properly invest in a training programme on the use of bibliographic software Learn how to use search databases Befriend your librarian! Keep records of your ongoing work to prevent panic later on! Be charitable to others work whilst at the same time evaluating it! Remember there is no such thing as a perfect review!

30 Recommended Reading List Bettany-Saltikov, J.B. (2012) How to do a systematic literature review in nursing. Open University Press, England Gough, D., Olivers, S. and Thomas, J. (2012) An introduction to systematic reviews. Sage, London Greenhalgh, T. (2010) 4 th ed. How to read a paper Wiley-Blackwell, Oxford Hart C. (2007) Doing a literature review: releasing the social science research imagination. Sage, London Hart C. (2001) Doing a literature search. Sage, London Petticrew, M. and Roberts H. (2006) Systematic reviews in the social sciences Blackwell publishing, U.S.A. Rudestam, K.E. and Newton R.R. (2007) 3 rd ed. Surviving your dissertation Sage, London