[OPST 195]: Lec. 3 - Searching and Reviewing the Literature

• explores and evaluates literature on a specific topic

• determines what is known on a topic and how well this knowledge is established

• tells what had already been done

literature review

literature review in research

literature reviews is a generic term for published materials

Examples of Literature Reviews

• scoping review

• mapping review

• systematic review

type of knowledge synthesis that maps key concepts, sources, and evidence in a broad research area to give a preliminary overview of the nature and extent of existing literature

Scoping review

a systematic and transparent method that categorizes existing evidence to show what research exists, where gaps remain, and to guide future reviews or primary studies

mapping review

a rigorous method of minimizing bias by comprehensively identifying, appraising, and synthesizing studies on a specific topic, often including a meta-analysis to combine data into a single summary estimate

systematic review

Importance of literature review

• contributes to almost all steps

• serves as foundation

• of a research project

Literature review process

1. Identify question

2. Search literature

3. Read critically

4. Synthesize

5. Write review

Conducting a literature search

• involves the first 2 steps of the lit review process (identofy question, search lit)

Principles of lit. search

1. systematic

2. explicit

3. rigorous

4. thorough

plan your search strategy

sytematic

document your actual searching process all throughout

explicit

adhere to rules you initially set

rigorous

cover almost all relevant studies

thorough

Tools

• search engines: information retrieval systems: pubmed, google scholar, ovidsp

• bibliographic databases: contain lists of citations of published and unpublished references

• reference management software: any software product used for storage and retrieval of bibliographic records: mendeley, zotero, endnote

Literature Review Steps

1. identify search terms

2. plan/select search strategy

3. implement and adjust strategies

4. retrieve and organize literature

• analyze research topic, identify key concepts

• pico framework

step 1: identify search terms

PICO

• patient/population

• intervention (exposure

• comparison

• outcome

when doing this, consider: synonyms, hypernyms, hyponyms, acronyms, technologica differences

• deside scope of review

• consider comprehensiveness and practicality

• identify databases

step 2: plan/select search strategies

national library of medicine’s controlled vocabulary thesaurus for indexing article for the medline/pubmed database

MeSH (medical subject headings)

BOOLEAN LOGIC & RELATED OPERATORS: And

retrieves articles that contain all the terms

• narrows down the search

BOOLEAN LOGIC & RELATED OPERATORS: Or

retrieves articles with any of the terms

• broadens the search

BOOLEAN LOGIC & RELATED OPERATORS: Not

eliminates the articles containing the second term

• narrows down the search

Other operators: ()

• parentheses: grouping operator

• groups terms/sub-queries togehter

  • those inside the parentheses are evaluated first before boolean operators

Other operators: ““

• quoatation marks: exact phrase search

• exact phrase/sequence of words

Other operators: *

• asterisk: truncation or wildcard operator

• used as a truncation symbol to retrieve variation of a root word  by replacing zero or more characters at the end of the word congress*=congressional, congressman

• for keyword search, applies to titles and abstracts or articles

• prompted by the number of hits from the initial hits

• can be narrow search through filters or broaden 

step 3: implement and adjust strategies

ways to broaden the search

1. related articles search

2. ancestral search: tracking down references of an article

3. citation search

4. gray literature: looking at unpublished/published in non-commercial form

• if cant access, email the first author of the article

• discriminate between relevant and irrelevant articles

• document the search

step 4: retrieve and organize lit.

Crtitical reading strategies

1. identify type of source

2. get ng info about the study

3. skim the abstract, headings, and conclusion; read only what you need

4. ask questions before, during, reading

5. take note of useful info

6. critically appraise relevant studies

Note-taking strategies

1. charting method

2. sentence method

3. cornell method

4. mapping method

list of points, create column for each one, note down references in each column

charting method

write down ideas as a sentence

sentence method

in one column write your own summary, on the other, write your own assessment and critique

cornell method

write down key concepts and terms, relate them

mapping method

journal article structure

• brief and concise

• 1-2 pages

• assumes reader has some knowledfe

• only cite what is pertinent 

• emphasize pertinent findings

master’s thesis structure

• comprehensive

• 20-40 pages

• exhaustive review

• present chornological progressions of knowledge

• funnel model

• introduce problem first, then set contect, analyze past research, then narrow to the one closes to your own

Topic/Problem/Rationale qs

a. What made you think of doing

the study?

b. What makes this problem

worth solving?

c. Must be straight to the point.

Known qs

a. What has already been done

to solve the problem?

b. In relation to this, what sort of

questions have already been answered

Gap qs

a. What sort of questions have

yet to be answered?

b. What questions may not have

been adequately answered by

previous studies?

Primary sources

■ Government reports,

Conference proceedings

■ Original artwork, Poems,

Photographs

■ Speeches, letters, memos,

interviews

Secondary sources

■ Literary criticism and

interpretation

■ Reviews of law and legislation

■ Political analyses and

commentaries