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EGIS (Energy, Geoscience, Infrastructure and Society): Selecting and combining keywords

Which Keywords / Search terms / Phrases / Combinations should I use?

Keywords are important! The words you use will determine how successful your search results are. Think about what you know already and what you need to find out about. For example, let’s assume you have a topic title e.g. "Energy Efficient Housing". How well do you know this topic? If this is an entirely new topic to you, the first stage will be general background reading (not journal articles). Having a better understanding of the topic, will give you a better idea of the vocabulary/keywords used, the sorts of questions you might want your dissertation/essay to answer and the sub-topic/chapters that you will research.

The reason you would want to ask yourself questions is that although "Energy Efficient Housing" is a good starting point, when it comes to looking for research conducted in this area, you may want to be both broader...and more specific e.g.: To have a broad overview of this topic, you might want to look at:

  • Energy Efficient/efficiency, but maybe also:
    • Carbon neutral
    • Eco
    • Passive
    • ​Green (not “greenhouse”)
    • Low energy
    • Zero energy (zeb)
    • Sustainable


  • Housing/houses, but maybe also:
    • House/Haus
    • Home/s
    • Building/s
    • Design
    • Architecture/architectural
    • Construction

Thinking about more specific areas of interest, you might want to look at:

  • Specific type of construction? (Larsen Truss Construction, Stick Frame Construction, Straw bale construction, Prefabricated homes (frame and insulation combined), Log Walls, Dome homes, Double wall construction, Super insulation, SIPs (Structural Insulated Panels), Insulated Concrete Forms (ICF) / Rastra, Papercrete)
  • Insulation (heat retention/energy loss/ventilation/air tightness/thermal performance)
  • Windows (size, orientation, technology)
  • Roof
  • Utilities - heating/electricity, sanitation (solar, heat pump, rain water tank, wood heating, heat exchanger, geothermal...)
  • Landscape/house orientation?
  • Household appliances, lighting etc? 

Therefore, sometimes you have to use broad concepts/keywords (to get a better understanding of a topic) and narrow concepts/keywords when you want to pinpoint more specific research/developments.

The likelihood is that each sub-topic/chapter/area will have different keywords that you will use to find the information you want i.e. you will never find all the information you want with one search for 'Energy Efficient Housing', rather it is likely that you will do several different searches specific for each chapter/area of interest.

Advanced keyword searching

If you wish to undertake a more systematic/comprehensive search, you need to think about all of the possible synonymous terms that could be relevant for your research questions and how you would combine these.

  • The default for most search engines/databases is to AND your terms together.
  • For synonymous terms (i.e. different words that mean the same thing), you need to specify that the database should OR these terms.
  • As well as synonyms, you need to think about variations of the same word e.g.:
    1. different endings of the same root word e.g. contaminated or contamination or contaminants.  Here, you can use a truncation symbol (usually *) to find all variants e.g. contamin*
    2. whether you want to force a phrase search e.g. "sustainable drainage systems", "marine protected area"
    3. any acronym/initialisms/abbreviations e.g. SDS, MPS, BIM, REITS, NTR etc
    4. any technical/medical variations e.g. heart attack or myocardial infarction or MI
    5. any spelling variations e.g. globalisation or globalization
  • If you want to exclude any word from you search you can use the NOT operator, but this should be used with caution (see the Logical/Boolean Operators section below)

A simple example of the above could be:

  • [fish* or invertebrate* or scallop* or lobster*] AND [“marine reserve*” or “marine area” or MPA]

Subject headings, thesaurus and controlled vocabulary

Many databases use subject headings, thesaurus and/or controlled vocabulary, that can help identify keywords/search concepts.  Get in touch for further details.

More about "phrase searching"

Sometimes you might want to force a phrase search e.g. rather than searching for [building and information and modelling] you want it to search for ["building information modelling"]

Think carefully about using exact phrase match e.g. “carbon emission reduction” would not find “reduction of carbon emissions”

Most databases allow "phrase searching".  Scopus also has an {exact phrase match} where you can put your phrase in curly brackets.  Again, be careful with this as it may exclude relevant results.

If you don't want to phrase search then you might want to consider proximity operators (see below).

Logical/Boolean Operators

You combine your search terms with AND, OR, NOT.   Use the tabs to find out more.

Each database may work differently, always consult the search help (or get in touch) if you are unsure or if you are not getting the results you had hoped for.


If you don't specify, most databases will AND your terms together.  Example:

  • keyword 1 = marine
  • keyword 2 = biology

Search = [marine biology]


= only those results in intersection 3 (i.e. that have both search terms)


Should be used where you need to find any variations of the same word.  You need to tell the database that you want to OR your terms.  Example:

  • keyword 1 = ocean
  • keyword 2 = marine

Search = [ocean or marine]


= any search results that have either keyword 1, or keyword 2 or both keywords (intersection 3)



This operator can be used to exclude irrelevant results, but should be used with caution.  Example:

  • keyword 1 = solar
  • keyword 2 = wind

Search = [solar not wind]


= results from section 1 only excluding results that contain keyword 2, but also excluding those results that contain 1 and 2 (intersection 3) so possibly excluding relevant results


Many databases allow the use of proximity operators, which specify how many words apart your keywords should be:


  • Preceding (Pre/n): The first word must be no more that (n) words apart from the second word
  • Within (W/n): It doesn’t matter which word comes before the other

Note: You cannot use the AND operator as an argument to a proximity expression.

Web of Science

  • NEAR/x: It doesn't matter which word comes before the other

Note: You cannot use the AND operator in queries that include the NEAR operator.

Other databases

Each database may differ, so check if proximity operators are allowed and how to use them.

Once you have decided on all of your synonymous terms and abbreviations, you should group them together as one search, e.g.:

Search 1:

[fish* or invertebrate* or scallop* or lobster*]

Search 2:

[“marine reserve*” or “marine area” or MPA]

You can then use the database functionality to combine your searches, e.g.:

Search 3:

search#1 AND search #2

This is equivalent to a search for:

(fish* or invertebrate* or scallop* or lobster*) and (“marine reserve*” or “marine area” or MPA)

It is better to split your search this way, rather than doing one search for (fish* or invertebrate* or scallop* or lobster*) and (“marine reserve*” or “marine area” or MPA).  Splitting it makes it easier to identify any errors and to edit your search, should you think of additional terms.

Undertaking and keeping track of your searches

It is likely that you will need to search across multiple databases and adapt your search strings to each database.  You will need to balance search specificity and specificity (depending on your project scope).

It is important to keep track of your searches and we recommend registering with the database so you can save your searches.


For help with systematic searching (developing your search terms, defining your inclusion/exclusion criteria, selecting and effectively searching appropriate databases, and managing your search results), please contact the EGIS Librarian.