Tag Archives: Scopus

Strategies for systematic literature searching


Image by Philm on Flickr (CC BY-NC-SA)

Literature reviews are a crucial part of the research process. Being able to search for the literature effectively is key to ensuring that you identify information for your research topic. Ultimately, a literature search should help you to identify gaps in the literature, as well as identify appropriate techniques or methodologies (Booth, Sutton & Papaioannou, 2016).

Of course, when searching the literature you shouldn’t restrict yourself to one database and one database alone. Rather you should seek to identify what databases will be relevant to your research topic and then seek to search them systematically, using the same keyword combinations and approaches across all resources as much as possible. So, for example, you shouldn’t settle on PsycInfo as the one database to search, you should look at others such as Academic Search Complete, ScienceDirect, CINAHL, Scopus etc etc (again, dependent on your topic).

Not only should you seek to search across a number of databases, you should also seek to employ a variety of strategies in conducting your searches. By using a variety of strategies across a range of databases, you ensure that you conduct a comprehensive search and, consequently, limit the chances of overlooking crucial papers that could have a serious impact upon your research.

The following are a number of key strategies to employ when searching the literature. They should never be used in isolation, they should be used in conjunction with each other to ensure effective lierature searching.

Thesaurus Searching

Thesaurus searching is a good and effective way to find all of the articles on a particular topic. Some databases (eg PsycInfo) use a subject term index to categorise articles. These terms are used consistently across the database, minimising the kind of variation you see with author keywords that are applied to articles (different authors may well use different keywords to describe the content of their articles). This is what is known as a controlled vocabulary (because there is over-arching control of the categorisation of all the articles).

Instead of searching the database, a thesaurus search requires the user to interrogate the thesaurus or subject index and use that to construct their searches (more on how this works on this video). As well as searching for an individual term, these subject terms can also be used in conjunction with each other (eg “Subject A” AND “Subject B”). When searching for a particular term, you can be pretty confident that all of the articles on that topic will be returned in your results.

However, it is not without its problems. New terminology or niche areas, for example, may not be indexed within the subject index (in which case you will need to do a keyword search). You may also find that it is quite a narrow search that results in a small number of results (depending on the topic), so you may need to broaden it out a little (which is again where a keyword search can help).

Advantages: Locates all the articles on a particular topic due to its use of a controlled vocabulary consistently applied throughout the database.
Disadvantages: May not be useful to find articles on emerging topics or niche areas of interest.

Databases: PsycInfo, Academic Seach Complete, CINAHL, MEDLINE (PubMed).

Keyword searching (free text searching)

Keyword searching is a much broader strategy and simply requires the user to enter their keywords in the search box to find results (much like how you would search on an internet search engine like DuckDuckGo). Compared to a thesaurus search, you are likely to find many more results, particularly if you only use one or two keywords. However, it is a more effective strategy for emerging or niche topics, because you will very quickly and easily find all the articles on that particular topic.

When keyword searching you can also use truncation (*) and wildcards (?) to help make your search more effective. So, for example, searching for child* would find child, children and childhood. Likewise, organi?e looks for organise and organize.

When using keyword searching, it’s best to restrict the search in the database to title, keywords and abstract, otherwise you may find you retrieve a large number of irrelevant results.

Advantages: Better for searching for niche or emerging topics if you use specific terminology.
Disadvantages: Can be too broad, returning large numbers of results which require careful filtering.

Databases: PsycInfo, Academic Search Complete, CINAHL, ScienceDirect, Scopus (and others).

Citation searching (bidirectional searching)

Citation searching can be a very effective way of finding studies. When finding useful papers, one of the first things most people do after reading it is look into the references to see details of the papers referred to in the article to then investigate. Bidirectional searching comes into effect when you look at not only the articles referenced in a particular paper (Paper A), but who has referenced Paper A.

Rather than searching for articles on a particular topic, you identify a key paper, then investigate who has cited that particular paper. You can thing dig into the papers that have cited that paper and repeat the process (this is known as snowballing). By digging into who has cited a particular paper or papers, you can quickly and easily build up a relatively decent amount of papers. Indeed, it is sometimes considered to be more effective than other forms of searching (Hinde and Spackman, 2015).

However, it’s worth noting that this kind of searching may not necessarily find all sources that cite a particular paper. Scopus, for example, indexes over 50 millions sources, but it’s primarily concerned with journal articles and books. Blog posts and other resources will not be picked up. Google Scholar, on the other hand, will include these kinds of web resources. However, the flip side to that is that there will consequently be more resources to plough through.

Advantages: Good way of building up literature by finding articles that have cited an article.
Disadvantages: Not all sources are necessarily indexed.

Databases: Scopus, Google Scholar.

Author searching

If you are aware of an author that has written a couple of articles on your research area, it may be worth digging into the rest of their research outputs. Scopus has an author search option (including an option to search by the author ORCiD) which can help you to find all their outputs (and, of course, all the times these outputs have been cited). You can also click on any author name in Scopus to find all the papers by that particular author.

Databases: Scopus.

Hand searching

Another way to search is to identify key journals covering your topic and search within them. Regardless of whether we have access to the journal in question or not, all journals enable you to at least search within them and have a look at the abstracts of the articles (you can then submit an inter-library loan if we don’t have access to one that you want).

Hand-searching can be effective, however it is a very time consuming process (Armstrong et al, 2005). One study (Greenhalgh and Peacock, 2005) found that a month of hand searching led to only 24 papers being identified – an average of one paper for every nine hours of hand searching (Booth, Sutton & Papaioannou, 2016). Of course, this could not be considered as a comprehensive method on its own, but it’s a useful additional strategy to employ.

Key Points

* Don’t rely on only one strategy. Use multiple techniques to ensure that you conduct a comprehensive literature search.

* Identify keywords and terms before you start searching. If you identify these first it will make the search process much easier and you will be less likely to miss key papers.

* Consider the databases you need to be using (as well as other resources) in the broadest sense. Will you need to look at clinical/health databases? Education databases? Searching in PsycInfo alone will not be enough. If your topic touches on other subject areas, then you will need to look at the relevant databases in other subject areas.

* Make sure, once you have identified your keywords, that you use the same keywords and keyword combinations across all the databases you search. This will help to ensure your search is comprehensive, as well as being systematic.

* Look for patterns when you search. If particular authors or journals keep cropping up, it may be worth considering an author search to find papers by a particular researcher, or hand searching to search more deeply into a particular journal.

* Google Scholar is useful for searching for grey literature, and can find more than citation databases or grey literature identification methods (Haddaway et al, 2015). However, as Haddaway et al note, it does miss relevant evidence and should not be used as a standalone resource. It should, as with other approaches, be used in combination with other search strategies.


Armstrong, R., Jackson, N., Doyle, J., Waters, E., & Howes, F. (2005). It’s in your hands: the value of handsearching in conducting systematic reviews of public health interventions. Journal of Public Health, 27(4), 388-391. http://dx.doi.org/10.1093/pubmed/fdi056.

Booth, A., Sutton, A. & Papaioannou, D. (2016). Systematic approaches to a successful literature review (2nd ed.). Croydon, UK: Sage.

Greenhalgh, T. & Peacock, R. (2005). Effectiveness and efficiency of search methods in systematic reviews of complex evidence: audit of primary sources. BMJ, 331, 1064-1065. http://dx.doi.org/10.1136/bmj.38636.593461.68.

Haddaway, N. R., Collins, A. M., Coughlin, D., & Kirk, S. (2015). The Role of Google Scholar in Evidence Reviews and Its Applicability to Grey Literature Searching. Plos ONE, 10(9), 1-17. http://dx.doi.org/10.1371/journal.pone.0138237.

Hinde, S. & Spackman, E. (2015). Bidirectional citation searching to completion: an exploration of literature searching methods. PharmacoEconomics, 33(1), 5-11. http://dx.doi.org/10.1007/s40273-014-0205-3.

Searching PsycInfo


Literature searching workshop for the School of Psychology

uel librarycard2 031
Need help with your literature searching? Then you might be intersted to know that I will be running another literature searching workshop for the School of Psychology in February. As with the sessions I ran in November, I will be covering PsycInfo, ScienceDirect and Scopus, as well as sharing some tips to track down articles you may have difficulty accessing.  By the end of the session you should be more confident in using these databases to conduct a thorough literature search as well as keeping you on top of the latest research.

The session is mainly aimed at postgraduates in the School of Psychology, but anyone is welcome to attend if they feel that the session will be beneficial. There are a limited number of places so students will need to book to ensure a place (click on the ‘book a place’ link below). Depending on demand, I will also be looking to run further sessions in the new year so don’t be disappointed if it is booked up, add your name to the waiting list anyway and I can then look to add further sessions if the demand is there. Keep an eye out for future dates by subscribing to this blog (see right-hand sidebar) or following me on Twitter.

Workshop: February 5th, 14:00-15:30, SL205 (Stratford Library) [book a place]

Comments received from previous workshops

“Move information than the previous literature search workshop I attended. Good to now about the accounts, saving searches and alerts.”

“Perfect pace and content level Ian, really added to what is already out there in the guides, without overwhelming.”

“A helpful session, thank you Ian!”

“Many thanks – very helpful!”


Need help with your literature searching?


You may have a vague memory of me showing you around some fancy online databases and demonstrating how you search them during one of the many induction sessions I ran over the past few weeks. Vague because, well let’s face it, you probably had a lot of stuff thrown at you during the hectic start of term period. I can’t really blame you if you can’t remember every detail from my library inductions, they are a blur for me let alone for you!

I try during my sessions not to go into too much detail about searching our specialised databases. With everything else you have to take in, I feel generally it’s best to introduce you to them but not get too bogged down in all the ways you can exploit these databases to their fullest extent. Consequently, instead of bombarding you during a fairly heavy session, I thought I’d run a couple of dedicated searching sessions a little while after the induction period so we can spend a more quality time looking at our resources.

On 5th November I will be running two sessions on database searching. How to conduct a literature search will be a more detailed look at how you can search our subscribed databases and the ways in which you can use them to help you with this part of the research process. The sessions will predominantly look at EBSCO PsycINFO, as well as ScienceDirect and Scopus. By the end of the session you should be more confident in using these databases to conduct a thorough literature search as well as keeping you on top of the latest research.

The sessions are mainly aimed at postgraduates in the School of Psychology, but anyone is welcome to attend if they feel that the session will be beneficial. Sessions are limited availability and students will need to book to ensure a place (click on one of the ‘book a place’ links below).

Session one: November 5th, 11:00-12:00, SL205 (Stratford Library) [book a place]

Session two: November 5th, 14:00-15:00, SL205 (Stratford Library) [book a place]

If you have any further queries regarding these sessions, please do not hesitate to get in touch via email, Twitter or phone.

email: i.clark@uel.ac.uk | twitter: @PsycLib_UEL | tel: 020 8223 3140

Top ten search tips


Image c/o Chris Ford.

  1. Keywords are, well, key

Before you even start searching a database, think of your topic and write out all the words that you would associate with that topic. You’ll find it much easier if you spend a few minutes doing this first before you dive straight into your search.

  1. A good thesaurus is your friend…

A thesaurus was always something I used when I wanted my essays to sound ‘clever’ (I’m just glad I was never asked to explain what a particular word meant!). But they are also incredibly helpful for searching databases. We all use different words to express the same things, a thesaurus helps you to find alternative words that researchers may have used in their papers. When drawing up your search terms, use a thesaurus to find alternatives to the words you have come up with.

  1. Recognize that English isn’t one language…

American researchers may use slightly different terminology to their British counterparts. Be conscious of terms commonly used in America but not in the UK eg pacifier for dummy, private school for public school etc… (there’s a good list here)

  1. Start broad then refine…

Don’t start off your search by putting in either too many terms or by being too specific. Stick to a couple of terms and try to keep it fairly general as a starting point. In most databases you can begin to refine once you have your initial results. Starting off too narrow could lead to you missing out crucial articles that may help you in your literature review. So, always start broad and narrow down.

  1. Consider what other databases are relevant…

Most databases have a particular subject focus. PsycINFO is, of course, a psychology database and therefore contains full-text and abstracts for a large number of psychology journals. However, what if your research area touched on issues around education or clinical psychology or coaching? If it does, you might want to consider searching the British Education Index, or CINAHL or Business Source Premier*. Don’t think that because your subject area is psychology you should just stick to dedicated psychology databases. As with point 4 above, think broad!

* Guides to all these databases are available on the Databases and E-Journals web pages.

  1. Do not overlook abstract/non full-text databases

Don’t restrict yourself only to databases that contain full text. The amount of literature out there is vast and we cannot subscribe to everything online. Use large abstract databases such as Scopus to find articles that are relevant to your research topic, check to see if we have access to specific journals using Library Search (A-Z search) or, if we do not have access, you can always submit an inter-library loan request.

  1. Build a snowball…

References at the end of journal articles are incredibly useful. The same is true of the literature review section of an article. By scanning through the list of references you may discover other articles relevant to your research topic. The article you discover might then point to other relevant articles. This method is referred to as the snowball method as you start with one or two papers and soon build up a sizeable list simply by scanning references.

  1. Look out for key authors and journals…

When you start searching you may find the same authors or journals cropping up. If so, look for more papers by that author or spend some time looking through a particular journal. Authors may have a particular area of interest that they focus on so you may find other papers they have written are highly relevant. Likewise, you may also find the same journals appearing in results. If so, have a look at the journal more thoroughly – there may be many other articles that may not deal with your specific research area, but may touch upon it.

  1. There’s always Open Access!

Not all research articles require a login to access. There is an increasing effort to make more research Open Access (OA), making it as widely available as possible by circumnavigating usual publisher restrictions. Consequently, there may be articles published as OA that you would not find in publisher databases. CORE is an excellent resource that provides access to over 20m OA articles. It’s well worth having a look to see if there is anything is relevant. And don’t forget UEL’s repository – ROAR!

  1. If you need any further help…

Need help with your search strategies? Finding it difficult to find the articles you need? Not sure how to use a specific database? Then maybe I can help! If you do need any support, drop me a line and we can arrange a one-to-one session to discuss any difficulties you are having and see if we can resolve them. Let me know when you are available and I will do my best to ensure I am free to help. Otherwise, feel free to email, phone or tweet (although the latter probably best for short simple queries!)