5.2 Developing a classification sheme

When developing a classification scheme, it is useful to work with members of the resource centre advisory committee (see Section 2.2) and/or other users, as these people will have a greater knowledge of the subjects to be covered by the resource centre. 

5.2.1 How to develop a classification scheme

Start with a brainstorming session, to identify as many subject areas of interest as possible. Compare the list of subjects with subject areas identified by the most recent needs assessment (see Section 1.1) to make sure that none have been missed.

On your own, write each subject on a separate piece of paper. Arrange the pieces of paper in order, ranging from broad subjects to narrower subjects.

When all the pieces of paper are arranged in a logical order, write down the order on a sheet of paper. Show it to the resource centre advisory committee or other users to obtain their agreement. Seeing the subjects in order will help them to notice if any subjects are missing.

Once the list of subjects has been agreed, write a classification number next to each subject. It is best if the classification numbers are made up of letters and numbers. It is easier to remember the letter(s) for a main class, combined with a number for a subsidiary class, than a long list of numbers. It also makes it easier to distinguish different classes on the shelf, both when looking for materials and re-shelving.

Do not automatically assign a full sequence of letters (ABCDE…) or numbers (12345…). It is important to leave gaps that can be used when new subjects are added, or when subject areas are expanded. The examples of the Healthlink Worldwide Classification Scheme in Section 5.2.3 show that there is plenty of room to add new classification numbers for main subjects, but little room for expanding the HC classification.

5.2.2 How to extend the classification scheme

If the resource centre collection expands into new subject areas (for example, emerging diseases such as hypertension), you may need to add new subjects to your classification scheme.

First, check the classification scheme carefully to make sure that there really is no suitable subject to describe the new material. Then find the most appropriate place in the list to add the new subject. Decide whether it is a main subject or a subsidiary subject, and add it next to the subject most similar to it. Give the new subject a classification number and description.

If possible, give a classification number that leaves room for further expansion. For example, in the Healthlink Worldwide Primary Health Care Classification Scheme subsidiary subject areas, the new subject, ‘Hypertension’ (a kind of cardiovascular disease) could easily be added after the subject ‘Cardiovascular diseases’ and assigned the classification number HC9.24 (see below).

5.2.3 Healthlink Worldwide Primary Health Care Classification Scheme

Healthlink Worldwide compiled its own classification scheme in the mid-1980s. The scheme has been revised regularly to incorporate new subject areas covered by Healthlink Worldwide’s resource centre, reflecting emerging health issues.

The scheme covers the main subjects in primary health care and disability issues. Each main subject area is identified by two letters. For example, materials on diseases and disease control are identified by the letters HC. Each main subject area is divided into more specific, subsidiary subjects which are identified by numbers. For example, materials on immunisation are identified by HC3 and materials on non-communicable diseases are identified by HC9.

The Healthlink Worldwide Classification Scheme is used by many organisations, in either its original or an adapted form.

Main subject areas

AB Culture & Society
AD Population

HB Community Health Care
HC Diseases/Disease Control
HE Nutrition
HJ Medical Services
HK Medical Equipment & Health Facilities
HL Women's Health
HM Mother & Child Health
HN Reproductive Health & Sexual Health
HO Children & Youth
HP Traditional Health Care & Alternative Therapies
HQ Disability & Rehabilitation
HR Oral & Dental Health
HS Urban Health
HV Health Planning & Health Management
HW Health Services
HX Health Personnel & Training
HY Health Communication
HZ Regional Information

TB Energy
TC Environment
TG Water & Sanitation
TH Food Production & Agriculture
TJ Gender & Development
TK Appropriate Technology
WA Information Services & Information Management

Subsidiary subject areas


HC1 Diseases & Disease Control – general

HC2 Diagnosis & Management 

HC3 Immunisation

HC4 Communicable diseases 
       HC4.2 tuberculosis
       HC4.3 sexually transmitted infections
       HC4.4 HIV/AIDS

HC5 Diarrhoeal Diseases

HC6 Respiratory Diseases

HC7 Parasitic Diseases
       HC7.2 malaria

HC8 Environmental Health & Occupational Health

HC9 Non-Communicable Diseases
       HC9.1 cancer
       HC9.2 cardiovascular diseases
       HC9.3 congenital conditions
       HC9.4 diabetes
       HC9.7 rheumatism / arthritis