High Level Reviews (systematic, integrative, scoping)

Once you have framed your search questions, the next step is to identify your search terms and limiters. See the Framing your question page for how we arrived at these questions.

You won't be searching for every word in the search question. You only need to use the words that represent your key concepts – your Keywords. Limiters are related to your inclusion and exclusion criteria. 

There are a number of techniques for this. For these examples, I've highlighted the keywords in the question, and circled any extra limiters that are related to inclusion/exclusion criteria, e.g. publication date range. It's possible for a work to be both a keyword and a limiter.

Example search question 1: Which high level reviews conducted by CQUniversity RHD students have been published in the last 5 years?

Example search question 2: What library support services do librarians in academic libraries offer to RHD students doing high level reviews?

You'll notice that RHD students is a limiter in example question 1, but a keyword in example question 2. This is because the RHD students in question 1 are individual authors whose names will need to be cross checked with a list of student names. In question 2, RHD students are a group of people to whom a service is provided.

For more information see Identifying the words to search for in our Database Searching guide.

When you know which words you are going to search for, it's a good idea to try and think of a few alternatives. You'll also find more of these extra terms as you search.

Arrange your keywords into a table or mind map and brainstorm alternatives including:

• synonyms (words that mean exactly or nearly the same),
• broader terms (the main area that your concepts belongs within) and
• narrower terms (often specific examples of the concept).

Example search question 1: Which high level reviews conducted by CQUniversity RHD students have been published in the last 5 years?

Example search question 2: What library support services do librarians in academic libraries offer to RHD students doing high level reviews?

Tip: Think about alternative spelling and plurals

• Consider alternative spellings for your keywords – British and American spellings are different for some words. You don’t want to miss relevant articles by missing out one of the variations. For example haemorrhage (British) and hemorrhage (American).
• Consider common misspellings for your keywords – Sometimes the spelling varies on difficult words and isn’t picked up before publication. For example in MEDLINE you can find articles by searching for these misspellings: haemmorhage, haemmorrage, haemmorrhage, haemorage, haemorhage, haemorrage, haemorrhage, hemmorage, hemmorrhage, hemorage, hemorhage, hemorrage, and hemorrhage.
• Try both the plural and singular forms of the word. Some databases and search engines work best with the singular form of the keyword, e.g. trial. Some prefer the plural, e.g. trials. For others you will need to include both as separate terms, e.g. trial OR trials.

For more information see Identifying the words to search for in our Database Searching guide.

Subject terms, also known as subject headings, are set terms used to group documents by topic in databases. You can use these in addition to you keywords to refine your search, because multiple keywords will come under the same subject heading.

There are several ways you can use your keywords to locate matching subject terms:

• Look at your search results. Database records usually include the subject terms in each item record. These terms are hyperlinked so clicking on them will take you to a list of records grouped under that heading. 
• Each database is different, but subject headings are often a search limiter. You might find them as fields to search in the record, or as an option in the side menu of limiters.
• Health and medical disciplines use specialist Medical Subject Headings (MeSH). These are organised in a structured hierarchy of headings and subheadings. You can usually search the thesaurus of subject terms, and find subject terms in records from a keyword search. The Using Health and Medical Sciences guide has more information about MeSH.

Not all databases use MeSH, some common medical databases and their controlled vocabularies are listed below.

Different databases can sometimes use different subject headings. You will need to take this into account when you are developing your search strategies.

Because you are searching systematically for your high level review, the terms you use need to be repeated in all of the databases you use. Any subject term that isn't common to all of your databases, must be included as a keyword where it's not available as a subject heading. For example if the MeSH term in Medline is “Physical Therapy Modalities” and the subject heading for physiotherapy in the CINAHL thesaurus is “Physical Therapy”, Your Medline search will have “Physical Therapy Modalities” as a subject heading and “Physical Therapy” as a keyword. Conversely your CINAHL search will have “Physical Therapy” as the subject heading, with “Physical Therapy Modalities” as the keyword.

If you are doing research in one of the health disciplines, there is specialised software to assist in identifying subject headings and keywords. Below are some of the text mining tools available.

• Yale MeSH Analyser – Use the PubMed artcle ID number (PMID).

• PubMed PubReMiner – Enter your search terms to find details of articles including author keywords and MeSH

• NLM MeSH on Demand – identifies MeSH terms from your research question.

• Voyant – Analyse the full text of all or part of an article.

Format your search terms to make maximise their effectiveness. For example, if your concept uses two or more words, a phrase search will be much more efficient than searching for those words separately. It focuses your search and eliminates a lot of useless results.

Keywords from the 2 example search questions formatted for searching

• “library support services”, support, assistance, training, "help guides", “library guides”
• librar*, “academic librarians”, “research librarians”
• “academic libraries”, “university libraries”, “college libraries”
• “RHD students”, “research higher degree students”, “higher degree research students”, “HDR students”, “PhD students”
• “high level reviews”, “integrative reviews”, “scoping reviews”, “systematic reviews”
• CQUniversity, CQU, “Central Queensland University”

You can see that phrase searching is the most common technique required for these searches, but librarian/librarians has changed to librar*. If you are using a combinations of database allow truncation and those that don't, you'll need to change this to an OR search, e.g. (librarian OR librarians), in all of your databases for consistency. See "Combine your search terms to form a search" below for more information on combining your search terms.

For more information see Formatting the words for searching in our Database Searching guide.

Databases and search engine are programmed to recognise and respond to specific words and symbols in a search. You can use these operators to combine your search terms so the database knows what to look for an how. The words AND, OR and NOT have to be in capital letters to work.

Examples of using these techniques to form search strings from our example search questions

1. (“high level review” OR “integrative review” OR “scoping review” OR “systematic review”) AND (CQUniversity OR CQU OR “Central Queensland University”)

2. (“high level reviews” OR “integrative reviews” OR “scoping reviews” OR “systematic reviews”) AND (“RHD students” “research higher degree students” “higher degree research students” “HDR students” “PhD students”) AND (“academic libraries” OR “university libraries” OR “academic librarians” OR “research librarians” OR librar*) AND (“library support services” OR support OR assistance OR training OR “help guides” OR “library guides”)

For more information see Turning the words into searches in our Database Searching guide.

Not all of your inclusion and exclusion criteria are going to fit into your search string. Some of them, such as publication date range are applied using database limiters to filter your search results. Publication date range is a standard option, but these limiters do vary from database to database. Some examples are listed below:

For our example question the limit is "published in the last 5 years". You would use the date range option to set your beginning and ending year of publication.

Different databases use different search syntax, operators, and default search fields. When you are remapping your master search to your chosen databases, it is important to consider whether you will need to adapt any aspects of your search strategy such as phrase searches, truncation, wildcards, and adjacency.

Finding the evidence: key search tips (PDF) by UniSA explains the differences in search syntax and operators in various databases.