During your PhD, you will need to interact with earlier research for various tasks and purposes. This section will help you find and retrieve the previous research, which usually take the form of published research books, conference papers, and articles.
On this page you will find information on the following:
When preparing a search strategy to match your research questions, it is a good idea to divide the question into components, creating search subsets for each component, and the combination of these subsets will be your search strategy. Your research question will usually involve several elements, such as the methods you will employ, the topic of inquiry, and possibly the setting. For some research questions, it is useful to have more than one search strategy.
Search approaches vary across disciplines and research fields. In medicine, there may be a need for a systematic search for a review ahead of a clinical trial, whereas search in the humanities and social science is part of the research process itself and can have a strong impact on it or even the research question. While there is no one method to fit all search needs, there are some common techniques which can be employed in most reference databases.
Examples of research questions:
“I consider it extremely important to be as in touch with the literature as possible of course.” PhD candidate
Bibliographic databases differ from internet search engines with regard to both subjects covered and search functionality. In addition to basic bibliographic information, they may include abstracts, full texts, citations and other valuable descriptors of content. Bibliographic databases typically add value by supplying controlled search vocabularies, which are needed for systematic searching.
Published research is indexed in bibliographic reference databases. These databases are designed to allow our searches to be documented, transparent and reproducible, building on the same principles as other aspects of our research. Search engines for everyday information adapts to us and our information need, thus searching for research publications can feel more cumbersome.
When your purpose is to identify the seminal literature of your field, search engines such as Google Scholar offer convenient features to provide you with an initial overview. However, when your aim is to do a thorough search, you need to search specialized bibliographic databases. Diligent use of both options will enable you to conduct a rich discovery of the literature in your field.
The example below show a bibliographic record from the database PsycINFO, and the fields of the record show us what is indexed when a reference is added to the database. Knowing how an article is indexed can aid us in developing efficient search strategies.
Accession Number: 2016-30160-003
Title: Parental divorce and initiation of alcohol use in early adolescence. [References].
Publication Date: Jun 2016
Year of Publication: 2016
Publication History: Accepted: Jan 2016
Revised: Jan 2016
First Submitted: Oct 2015
Author: Jackson, Kristina M; Rogers, Michelle L; Sartor, Carolyn E.
E-Mail Address: Jackson, Kristina M.: firstname.lastname@example.org
Correspondence Address: Jackson, Kristina M.: Department of Behavioral and Social Sciences, Center for Alcohol and Addiction Studies, Brown University, Box G-S121-4, Providence, RI, US, 02912, email@example.com
Institution: Jackson, Kristina M.: Department of Behavioral and Social Sciences, Center for Alcohol and Addiction Studies, Brown University, Providence, RI, US
Rogers, Michelle L.: Hassenfeld Child Health Innovation Institute, Brown University, Providence, RI, US
Sartor, Carolyn E.: Department of Psychiatry, Yale University School of Medicine, New Haven, CT, US
Source: Psychology of Addictive Behaviors. Vol.30(4), 2016, pp. 450-461.
Publication Month/Season: Jun
NLM Title Abbreviation: Psychol Addict Behav
ISSN Print: 0893-164X
ISSN Electronic: 1939-1501
Other Serial Titles: Bulletin of the Society of Psychologists in Addictive Behaviors, Bulletin of the Society of Psychologists in Substance Abuse
Publisher Information: American Psychological Association; US
Other Publishers: Educational Publishing Foundation, US; Society of Psychologists in Addictive Behaviors
Format Covered: Electronic
Publication Type: Journal; Peer Reviewed Journal
Document Type: Journal Article
Abstract: Parental divorce/separation is among the most commonly endorsed adverse childhood events. It has been shown to increase subsequent risk of alcohol dependence and problems across adolescence and early adulthood, but its influence on early stages of alcohol involvement has only recently been explored. In the present study, we examined whether time to first full drink was accelerated among youth who experienced parental divorce/separation. To determine specificity of risk, models controlled for perceived stress as well as family history of alcoholism, current parental drinking, and internalizing and externalizing problems. Developmental specificity in terms of timing of both parental divorce and first drink was also examined. Participants were 931 middle-school students (488 girls, 443 boys) who were enrolled in a prospective study on drinking initiation and progression (52% female; 23% non-White, 11% Hispanic). Students indicated whether and at what age they had consumed a full drink of alcohol. Parental divorce/separation was coded from a parent-reported life-events inventory and was grouped based on age experienced (ages 0-5, ages 6-9, age 10+). Cox proportional hazard models showed increased risk for onset of drinking as a function of divorce/separation, even controlling for stress, parental alcohol involvement, and psychopathology. There was no evidence for developmental specificity of the divorce/separation effect based on when it occurred nor in timing of first drink. However, the effect of parental divorce/separation on initiation was magnified at higher levels of parental drinking. Given the rates of parental divorce/separation and its association with increased risk of early drinking, investigation of the mechanisms underlying this link is clearly warranted. (PsycINFO Database Record (c) 2016 APA, all rights reserved)
Digital Object Identifier: http://dx.doi.org.galanga.hvl.no/10.1037/adb000…
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Key Concepts: divorce, childhood, adolescence, alcohol, initiation
Subject Headings: *Alcohol Drinking Patterns
PsycINFO Classification Code: Drug & Alcohol Usage (Legal) 
Population Group: Human; Male; Female.
Childhood (birth-12 yrs); School Age (6-12 yrs); Adolescence (13-17 yrs)
Methodology: Empirical Study; Longitudinal Study; Prospective Study; Quantitative Study
Tests & Measures: Coddington Life Events Questionnaire for the Elementary Age Group
Perceived Stress Measure
Family History of Drinking Problems Measure
Alcohol Use Disorders Identification Test
Child Behavior Checklist
Test DOI: Alcohol Use Disorders Identification Test [doi: http://dx.doi.org.galanga.hvl.no/10.1037/t01528…
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] (9999-01528-000) [PsycTESTS Record Link for subscribers]
Grant/Sponsorship: Sponsor: National Institutes of Health. US
Grant: R01 AA016838 and K02 AA13938
Recipient: Jackson, Kristina M.
Sponsor: National Institutes of Health. US
Grant: K08 AA017921
Recipient: Sartor, Carolyn E.
Copyright: HOLDER: American Psychological Association
Cited References: Achenbach, T. M. (1978). The Child Behavior Profile: An empirically based system for assessing children’s behavioral problems and competencies. International Journal of Mental Health, 7, 24-42. http://dx.doi.org.galanga.hvl.no/10.1080/002074…
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Finn/bestill i Oria Finn/bestill i Oria
Amato, P. R. (2000). The consequences of divorce for adults and children. Journal of Marriage and the Family, 62, 1269-1287. http://dx.doi.org.galanga.hvl.no/10.1111/j.1741…
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Bibliographic Links Finn/bestill i Oria
Amato, P. R. (2001). Children of divorce in the 1990s: An update of the Amato and Keith (1991) meta-analysis. Journal of Family Psychology, 15, 355-370. http://dx.doi.org.galanga.hvl.no/10.1037/0893-3…
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Bibliographic Links Finn/bestill i Oria
An increasing number of search engines provide scholarly content. They can be excellent for the efficient retrieval of information. In particular, Google Scholar offers convenient, simple access. The service also provides links to your library holdings and information about citing documents in both Google Scholar itself and Web of Science. However, remember that
Not posted on the web
Not linked to and therefore not found by a crawler
Placed beyond paywalls
Hidden in databases
Located within private sites of organizations, governments and companies
Not found because of your personal settings
Listed beyond the first pages
Databases offer a variety of options such as filtering and sorting, expanding or limiting, and specific search techniques like applying wildcards, phrase searches, operators and use of search strings or search history to aid in the development and execution of the search.
There is some variation between databases as to what kind of search functionality they support. In the following, you will find a description of common functionality available in most databases. You can always check the help section of the database for information on search functionality.
Wildcards help you include alternative spellings or word forms. A wildcard replaces character(s) of a word to enable searching for variations in spelling. When used to search with word stems, we call it truncation.
When you search for a specific phrase, enclose the phrase with double quotation marks (“…”). This narrows your search to those exact words in that specific order.
Examples: “United Nations”, “breast cancer”
The use of AND, OR and NOT, called Boolean logic, helps you to combine your search words.
These operators let us search for keywords that express relations, as in words that often appear together, but are not fixed expressions. By using proximity operators we can specify the order of words and the number of words that can separate them. Most databases have proximity operators, but the command used vary from one database to the next. Below you find some examples of proximity operators.
By enclosing your search terms in parentheses, and using Boolean and proximity operators you can combine several keywords and build complex search strings. Remember that expressions in inner parentheses are searched first.
Example: ((“common cold” OR influenza) AND (garlic OR vitamin* OR “antiviral treatment”))
As search strings can be difficult to read for searches with many elements, most databases have the functionality of combining searches through search history. In bibliographic databases all searches you do will be remembered by the database for the duration of your search.
When you search for a document by a specific author, be aware that author names are presented in different ways across databases. Names might not be given in their full form; for instance, they may be presented with last name and initials only and will therefore only be searchable as such.
For the most complete result, a good strategy is to search for all possible variations of a name. Use wildcards to include different types of spelling.
Topic information is typically found in titles, abstracts, keywords or subject headings. Using keywords that describe your topic is an efficient way of searching. This kind of searching is often referred to as text word searching.
You should note that different keywords are used to describe the same phenomenon, and conversely, the same keywords may be used to describe very different phenomena. You will therefore need to think about relevant synonyms when searching. Using a thesaurus or subject heading will help you do this.
Some subject-specific databases maintain a controlled, hierarchical vocabulary to support your search. Searching the controlled vocabulary from a thesaurus is useful because it covers synonyms and closely and distantly related keywords.
Make the remaining list of retrieved documents as relevant and precise as possible, familiarize yourself with the database that serves your area of interest and check whether you can apply specified filters to narrowing your search. You may, for example, filter your search by
Reference databases have functionality that allows you to manage your search and the search results.
Database vendors allow users to create accounts. Once you have an account, you can save your search in the database. If you have created a complex search, saving it will allow you to run the search again without having to type it all in again.
A long list of search results may be hard to browse and evaluate. Sorting and/or filtering the list might be useful.
You can sort results by:
Filter results by:
Two key terms in searching are sensitivity and specificity. High sensitivity casts the net wider; you try to find as much as possible of the relevant research literature, but you will also retrieve irrelevant hits in the databases. High specificity will make your search precise and relevant, but you may lose some of the relevant literature.
Depending on your need, you can use the following approaches:
To expand your search
To limit your search
If your results list yield many relevant hits, you will no doubt like to save these results for further use. You can save the result list in your database account. Another option would be to export the relevant results to a reference manager and save them there. The latter option allows you to use the results in your own writing.
Literature databases, publisher and journal websites, research blogs and social networks all provide newsfeeds (RSS) and research activity alerts which help you keep updated on recent research publications and developments in your field. Look for the following options:
“I use bibliographies of other books a lot. If I have a good book that is related to what I’m doing, then I always carefully read the bibliographies.” PhD candidate, social sciences
Tracing references is an efficient way of identifying relevant literature for your doctoral thesis. References connect present findings with pevious findings and put pieces of knowledge into a wider context. Cited or citing documents allow us to follow a discussion or development of a subject over time. Scholarly databases, such as Web of Science, Scopus and Google Scholar, are designed for tracing citations. These services give information on how often a document has been cited and by whom. How frequently a document has been cited is considered indicative of its impact and use by other researchers. You can use features in these so-called citation databases to:
Some databases, in particular book catalogues, do not incorporate citation networks. Some may however, provide statistical information on usage, such as counts of clicks and downloads. Usage measures may give you hints about the impact of a specific document and enable you to figure out trends or directions in a particular research area, and might therefore be helpful in your work.
When exploring your research field, it is useful to see who writes about what, and who collaborates with whom. As you read in your field and check reference lists, you will get a feel for this. However, this will take time and sometimes there is too much literature in your field for you to read all that may be relevant. One way around this is to follow the most important researchers in your field. Google Scholar allows the researcher to set up a profile, and will automatically collect and present the researchers work in the profile. As a researcher you should monitor this carefully to ensure only your own work is credited to you. When looking at other researchers’ profiles, you can ask to be notified when they publish new material, or when someone cites their work.
Although much information, including scholarly publications, is openly available on the Internet, the majority of the scholarly resources you will need are subscription-based. These are made available to you by your library.
Click the links to see the databases accessible at your institution. The lists of databases are organized both alphabetically and by subject. They are accessible from everywhere on campus. When you are off campus, check with your institution to find out how you can connect through proxy or VPN technology.
Visit your library website to learn about the services offered, such as courses and guidance in literature searching and reference management.