Section 8
Thesaurus Displays

For any thesaurus display, you may need to make several decisions. These decisions are likely to include Any of these decisions will, of course, be constrained in various ways. For example, the thesaurus construction software that you use may produce only certain kinds of displays or may not permit you to store a mixture of upper and lower case.

Which Types of Terms Will Have Entries?

A thesaurus display might have entries only for preferred terms; for example,
...
EX-CONVICTS
EYE EXAMINATIONS
EYE PATCHES
EYEGLASSES
EYES
FABLES
...

At least one of the displays, however, should provide entries for non-preferred terms as well, to allow users to browse through these for the correct preferred terms:

...
EXTREMISM
EX-CONVICTS
EX-MILITARY PERSONNEL
EYE CATCHERS
EYE EXAMINATIONS
EYE PATCHES
EYEGLASSES
EYES
FABLES
FABRIC DESIGN DRAWINGS
...

One of the displays might include entries only for top terms, preferred terms that have no broader terms. This choice is often combined with indicating multiple levels of narrower terms, in a tree display, as discussed below.

How to Indicate Special Types of Terms

You may want to mark certain kinds of terms in special ways. For example, you might put all the non-preferred terms in italics:
...
EXTREMISM
EX-CONVICTS
EX-MILITARY PERSONNEL
EYE CATCHERS
EYE EXAMINATIONS
EYE PATCHES
EYEGLASSES
EYES
FABLES
FABRIC DESIGN DRAWINGS
...
Of course, users of the thesaurus should be able to tell that a term is a non-preferred term if it has a USE reference after it, but displaying the term differently will serve as an added reminder.

The examples used in this tutorial generally show terms in all upper case. This is to emphasize that the distinction between upper and lower case should normally not be significant in indexing and searching using a controlled vocabulary. Nevertheless, you may prefer a mixture of upper and lower case for your thesaurus displays to make them easier to read. Mixing upper and lower case may be especially helpful for longer elements such as scope notes:

GOGGLES
SN Protective eye coverings.

What Types of Links Should be Shown to Other Terms

Taken as a whole, your thesaurus displays should cover all the term links that are important to the people who will use the thesaurus. In individual displays, you may choose to include only certain links. For example, a brief display might include only "USE" references:
EXTREMISM
USE RADICALISM
EX-CONVICTS
EX-MILITARY PERSONNEL
USE VETERANS
EYE CATCHERS
USE ARCHITECTURAL FOLLIES
EYE EXAMINATIONS
EYE PATCHES
EYEGLASSES
EYES
FABLES
FABRIC DESIGN DRAWINGS
USE TEXTILE DESIGN DRAWINGS

An entry in one of the displays will usually give all the links:

EYEGLASSES
UF SPECTACLES
BT MEDICAL EQUIPMENT AND SUPPLIES
BT OPTICAL DEVICES
NT MONOCLES
NT SUNGLASSES
RT CONTACT LENSES
RT EYE PATCHES
RT GOGGLES

Similarly, at least one of the displays would include the scope notes:

ALIDADES
SN TELESCOPIC SITING DEVICES USED AS PART OF A SHIP'S NAVIGATIONAL EQUIPMENT FOR TAKING BEARINGS
BT SCIENTIFIC EQUIPMENT
BT TELESCOPES
RT NAVIGATION

How Many Levels of Linking will be Shown

In one of your displays, you may wish to show indirectly linked terms as well as those linked directly to the entry term. This is mostly useful with links representing hierarchical relations. The display could indicate more than one level of broader term:
MONOCLES
BT EYEGLASSES
. BT OPTICAL DEVICES
. . BT EQUIPMENT
. BT MEDICAL EQUIPMENT AND SUPPLIES
Likewise, the display could indicate more than one level of narrower term:
OPTICAL DEVICES
NT BINOCULARS
NT CONTACT LENSES
NT EYEGLASSES
. NT MONOCLES
. NT SUNGLASSES
NT GOGGLES
...
As mentioned above, such a cascade of narrower terms is often used with top terms as entry terms.

How to Indicate Link Types

You can often omit the symbols for the different kinds of links if it is obvious what they are. So, you need to use a symbol such as "RT" only once for a series of terms all linked to the entry term with an "RT" reference:
...
RT EMPLOYEE EATING FACILITIES
EMPLOYEE FRINGE BENEFITS
EMPLOYEE RIGHTS
EMPLOYMENT
LABORERS
UNEMPLOYED

Similarly, if all the links in a display are of the same kind, as in a hierarchical display, you do not need to use a distinctive symbol:

EQUIPMENT
. AIRPLANE EQUIPMENT
. . AIRPLANE PROPELLERS
. . AIRPLANE WINGS
. ANCHORS
. APPLIANCES
. . AIR CONDITIONERS
. . DISHWASHING MACHINES
. . FREEZERS
. . REFRIGERATORS
. . TOASTERS
. . VACUUM CLEANERS
...

In a graphic display, different types of links can be represented by different kinds of arrows. For example, a link from a broader term to a narrower term can be represented by a one-headed arrow; and a link between related terms, by a two-headed arrow: .

Where the Linked Terms are Placed

Relative to the Entry Term

In a printed display, you will usually want the entry term to appear at the top left, because this makes it easy to search for. Variations are possible, though. For example, broader terms may be displayed above the entry term and narrower terms below:
. MEDICAL EQUIPMENT AND SUPPLIES
. . EQUIPMENT
. OPTICAL DEVICES
EYEGLASSES
. MONOCLES
. SUNGLASSES

In an online display of a single entry, there is more flexibility. For example, the broader terms can be arrayed on the left, the narrower terms on the right, and the related terms above and below:
MEDICAL EQUIPMENT AND SUPPLIES .
EQUIPMENT . .

OPTICAL DEVICES .
CONTACT LENSES
EYE PATCHES

EYEGLASSES
GOGGLES
. MONOCLES
. SUNGLASSES

Relative to Each Other

If all the links are indicated in the same position relative to the entry term, the best order to follow is generally For example,
EMPLOYEES
SN PERSONS IDENTIFIED AS WORKING FOR ANOTHER, BUT WHERE THE NATURE OF THE OCCUPATION, BUSINESS, OR INDUSTRY IS NOT KNOWN.
UF PERSONNEL
STAFF
WORKERS
BT PEOPLE
NT HOTEL EMPLOYEES
RAILROAD EMPLOYEES
RT EMPLOYEE EATING FACILITIES
EMPLOYEE FRINGE BENEFITS
EMPLOYEE RIGHTS
EMPLOYMENT
LABORERS
UNEMPLOYED

Within a group of terms linked in the same way to the entry term, the order is most commonly alphabetical, as in the example just given. Sometimes, however, you may wish to adopt a systematic order by subcategorizing the link types, especially if the lists are very long.


Section 7 Table of Contents Glossary
Last updated January 25, 2008, by Tim Craven
Copyright © 1997 The University of Western Ontario