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Information Literacy Skills for Research (Engineering): Locate - Search by Topic


Search by Topic means typing some keywords in a search box to retrieve lots of papers on a particular topic.

In Search by Topic, you could perform either one of the following:

  • Topic Search: Keywords or terms used to describe your topic are entered into a search box, e.g. author keywords, indexed keywords and abstract
  • Thesaurus Search: Terms or Controlled Vocabulary of a Thesaurus are used to search, e.g. synonyms, broader terms, narrower terms and related terms
  • A Google Scholar search: Check out the tips and tricks here

View a possible Search Progression.

Use Information Search Process in order to find more information on your topic.  It ends once you are satisfied with your results.  Familiarize yourself with the following Search Process:

  1. Identify Keywords
  2. Select Sources
  3. Construct Search Statement
  4. Set Alerts
  5. Access Full-Text

To find more articles, the search methods of "Trace References" and "Search by Topic" can be used interchangeably.

Formulating Your Search Strategy

Click on image below to view video (NUSNET access required)

Information Search Process

Search Process

Start with keywords describing concepts.  After that, look at the keywords you identified and see if they are sufficient to describe what you want.

For example, I want to look for information on memristor in neural systems.

You could identify keywords from:

  • Concepts describing the topic
  • Keywords listed in a research paper which is similar to the topic : author keywords, indexed keywords, abstract, controlled term
  • Thesaurus which has broader, narrower and related terms describing a topic (see below)
  • Variations/synonyms/alternative keywords or terms
  • Scientific or technical terms, e.g. seaweed vs micro-algae
  • Keywords with limited life span, e.g. Manufacturing Resource Planning or Material Requirements Planning (MRP) systems in 1970s-1980s vs Enterprise Resource Planning (ERP) systems in 1990s
  • Buzz-words, e.g. “phishing” vs computer crime
  • Keywords listed in the search results, e.g. look at the left pane of Scopus search result page (see below)

Source: Scopus

List them in Keyword Table:

Concept 1 Concept 2
memristor (CT) neural systems (CT)
memory resistor (CT) neural networks (CT)
memristive neuromorphic computing (CT)

** CT = Controlled Term

An example of Thesaurus Search in Engineering Village:

Source: Engineering Village

Select the search engines or databases to search in.

  1. For a quick search, search the library catalogue, e.g. FindMore
  2. For a more in-depth search, search an academic database, e.g. Engineering Village, Scopus, Web of Science and IEEE Xplore

To learn more about the differences between the above four databases, refer to this guide's Tools > Databases.

You may also refer to Engineering Subject Guide for relevant databases in your subject areas.

FindMore is NUS Libraries’ search engine to its collection of books, e-books, e-journals, DVDs, dissertations, research papers and more.  It is Google-like in the sense that it searches not just the tags or subject headings but also the full-text. That is why the number of results searches is usually huge.

An example of Topic Search using FindMore via Library Portal:

These are some search techniques you apply in databases:

  • Broaden Search
    • Boolean OR :: retrieves more results, e.g. chitosan OR chitin - means either one of these terms would exist in the document
    • Truncation Symbol :: retrieves words with the root word, e.g. appl* (apply, applicant, application, appliance, etc.)
    • Wildcard Symbol :: retrieves spelling variations, e.g. colo?r (colour, color)
  • Narrow Search
    • Boolean AND :: retrieves less results, e.g. tissue AND engineering - means all terms must exist in the document
    • Boolean NOT :: exclude the term from the results, e.g. chitosan NOT chitin
    • Phrase " " :: retrieves only documents that have these keywords side by side in the order specified, e.g. "memory resistors".
    • Field Search :: retrieves keywords in the specified fields of the databases, e.g. chitosan in Article Title
    • Limiters :: limits the search to a certain aspect, e.g. document type (review papers, conference papers), date range, language
  • Advanced Search Techniques
    • Adjacency/Proximity Operators :: this is used to achieve both comprehensiveness and relevance, e.g. memory NEAR5 resistors
    • Combine/Nesting :: complicated search statements could be combined or nested to make searches more efficient

An example of combination of search statements in Engineering Village:

Source: Engineering Village

Multiple search attempts would be required to retrieve results that you are satisfied with, e.g. I want to find any information on memristor and neural systems in Scopus:

Search Attempt Search Statement Explanation
1 memristor
"neural systems"
1.Initial Search statement combining the keywords with AND operator
2.Use phrase search
2 (memristor OR “memory resistor”)
(“neural systems” OR “neural networks” OR “neuromorphic computing”)
1.Add alternative terms and combine them using OR operator. 
3 (memrist* OR “memory resistor*”)
(“neural system*” OR “neural network*” OR “neuromorphic comput*”)
1.Use truncation to broaden search results.
4 (memrist* OR (memory W/5 resistor*))
((neural W/5 (system* OR network*)) OR (neuromorphic W/5 comput*))
1.Use proximity operator in place of phrase search to broaden search results and maintain relevancy

Search syntax for the above highlighted search terms in Scopus and  Engineering Village: 

Scopus Engineering Village
"memory resistor*" "memory resistor" OR "memory resistors"
memory W/5 resistor* (memory NEAR/5 resistor) OR (memory NEAR/5 resistors) 

Each database would have its own operators or symbols. Check the online help of each database to find out what the operators and symbols are:

  Engineering Village's Help > Quick Search

Scopus' Help > Search Tips

Web of Science's Help > Search Tools IEEE Xplore's Help > Search Tips
Boolean Operators AND


Truncation * * * *




" "
{ }

{} for exact phrase

" " for loose or approximate phrase
" " " "
Adjacency/ Proximity NEAR/n


Chemical Substance/ Compound

{Xx sub 9}
{Xx sup 9}
* subscript or superscript

e.g. {TiO sub 2} search for TiO2 (titanium dioxide)

CAS registration number: search "All fields" in Quick Search

e.g. 13463-67-7 for TiO2


e.g. TiO2/tio2 search for TiO2 (titanium dioxide)

CAS registration number: search "CAS Number" in Document search

e.g. 13463-67-7 for TiO2


e.g. TiO2/tio2 search for TiO2 (titanium dioxide)


e.g. TiO2/tio2 search for TiO2 (titanium dioxide)

Field Search


Yes Yes Yes
Limiters Access Type
Controlled Vocabulary
Document Type
Author Affiliation
Classification Code
Publication Year

Open Access
Publication Year
Author Name
Subject Areas
Publication Stage
Document Type
Source Title
Fund Sponsor
Source Type

Publication Year
Document Types
Publication Titles
Funding Agencies
Open Access
Group Authors
Research Areas
Conference Titles
Book Series Titles
Web of Science Index

Publication Title
Supplementary Items
Conference Location
Standard Status
Standard Types
Publication Topics

To keep updated on new or the latest published articles, look at Search History to set alerts of RSS/email feeds for the searches that are relevant.

Different databases would have different methods in setting alerts. Check the online help of the database to find out how:

Source: Scopus

Not all databases have the full-text of every document.

You can also get full-text from printed sources, e.g. printed books, journals, etc. These are located in various collections in NUS Libraries, e.g. Bound Journals, Closed Stacks, etc.

More details in Discover > Access.

Search Progression