Students working from reading lists become accustomed to using databases by searching for author and title, party names and citations, or legislation titles. Searching for sources by subject requires knowledge of the structure and content of databases and boolean searching techniques. This page explains the search terms, operators and connnectors, field searching and, briefly, natural language searching for the main legal databases.

Search terms

First, break your research question into key concepts and note the terms that can be used to describe these. One way to find suitable search terms is to find a relevant case or article in a database, and use the key terms provided for that. Westlaw provides a 'List of Terms' under the Subject/Keyword box in Advanced Search. Lexis Library provides 'Topics to Search' under the search box. Think of synonyms and antonyms and any possible spelling variations.

The example below shows key concepts and broader search terms for employment law.

Area of Law: Employment Law or Labour Law

Key Concepts: discrimination, EEO or equal employment opportunity, unfair dismissal, work conditions

Other Search Terms: racism, racial, sexism, harassment, severance, "dismissal procedures", "appeal against dismissal", "discrimination in the workplace", wages and conditions, "leave entitlements", "right to strike" etc

Search connectors and Boolean operators

Once you have identified your search terms, use Boolean logic to specify relationships between those words, to give meaning and context to the words you are searching. (Boolean Logic is an algebra of concepts developed by the mathematician George Boole in the 19th century.) Develop a habit of checking the search language of each database as you use it - as the table below indicates, many searching terms are not standard.

Useful search connectors


Lexis Library




Proximity searching – to find words near each other. The first example is a search for duty within 5 words of care. 

w/n, eg duty w/5 care

w/s  in the same sentence

w/p  in the same paragraph

/n, eg duty /5 care

/s   in the same sentence

/p   in the same paragraph

/n/, eg duty /5/ care

 ~ n eg, "duty care"~5

Phrase searching – to find words in a particular order, eg duty of care

No special treatment – use quotation marks only if the phrase includes AND or OR

Double quotation marks around the phrase, eg “duty of care”

As for Westlaw

As for Westlaw

Truncation symbol – to find various forms of a word, eg: neglig! will find negligence and negligent







Wildcard – to replace letters in a word, eg regulari*e for regularise or regularize

 * for one character

 ** for two characters etc

 * for one character

 ** for two characters etc


 ? for one character

 ?? for two characters etc

  ? for one character

 * for two or more characters



Boolean operators

Lexis Library



OR – to expand a search, eg ship OR vessel OR boat; to search for antonyms, eg creditor OR debtor; or spelling variations, eg trademark OR trade-mark





AND – to restrict a search, eg negligence AND medical; this is generally not a useful search in a long document.



AND, & or +

NOT – to exclude a word from a search, eg undertakings NOT contractAND NOT%notNOT

Search engines generally read the query from left to right. Terms inside ( ) are searched first, for example, if the search term is journalist AND (defamation OR publish) the OR search will happen firstLexis Library searches in this order: OR, w/n,w/p, AND, AND NOT. HeinOnline allows boosting a term to raise its relevancy ranking, for example, disaster^5 AND legislation returns documents that include the word 'disaster' more frequently than the word legislation at the top of the results. 

Sample connectors search

A search in Westlaw in Cases and Legislation for the phrase duty of care within ten words of education or educator or educational (which is expressed by using the root - educat - followed by the truncation symbol - !) or school.

"duty of care" /10 (educat! or school)

The same search in the Lexis Library front page. Note that in Lexis phrases do not require quotation marks, and the slash in the proximity search is preceded by 'w', which stands for 'within'.

duty of care w/10 (educat! or school)

Field searching

Modern databases offer simple field searching with boxes for Party Names, Court, Citation, Author, Title etc. However, if only a free text or general search box is available, it can be helpful to be familiar with field names and how to construct a field search. Field searching can be used in combination with boolean searching and connectors. The field name generally precedes the search term, which is generally inserted in brackets. It seems that as the databases grow, the field names become less useful or dependable, or it simply becomes more difficult to find out what they are. On the other hand, as both Lexis and Westlaw now allow easy searches across all sources from their front page, knowledge of field names and connectors can be useful.





ti or title

ti("constructive trusts")  or title("constructive trusts")

Authorau or authorau(endicott) or author(endicott)
Citationcite:cite(240 N.E. 2nd 860)

Sample field search

A search for any documents with Endicott in the author field.


Natural language searching

Many databases offer the option of natural language searching. The computer processes the words you have keyed in and perform a statistical analysis of the occurrence of these terms in the database. Type your search request as a normal question, eg must a manufacturer disclose the side effects of a drug?

A Boolean search for this information might read: "side effects" and manufactur* and disclos* and drug. Generally speaking, Boolean Logic gives you more control and is a more specific way to search than natural language searching. Both Lexis Library and Westlaw UK give you the option to use natural language when constructing a search.