Subjects, simple versus complex

What is a simple subject? and what is a complex subject?


Signs, symbols or linguistic expressions may be more or less simple or complex. The composite word "briefcase" is more complex than one of its components, e.g. "brief", but that does not imply that briefcases are more complex than briefs.  


Surely, H2O (water) is more complex than H (hydrogen). This is the case because chemical formulas reflect a structure. This complexity is not just in the expression, but also in the stuff represented by the expression. This is simply a property of the chemical symbolic system.


Byström (2002) examines perceived task complexity which is regarded as a combination of both task and individual characteristics. Tasks may be more or less simple or complex. The complexity of a task is relative. It depends on the tools and the skills of the person doing the task. Complex mathematical tasks, for example, are simple if you have a computer program (or just a mathematical formula) to do the job. They may be very complex for the amateur to do. Reading a text is a simple task for a person who is fluent in the language of the text, but it is a complex task for a foreigner with little knowledge of that language.




What about the subjects of documents?


Facet analysis as developed by Ranganathan and the British CRG, (cf., Langridge, 1976, p. 18-19) differentiate between simple and complex subject. In this theory is a simple subject a subject that can be expressed by the name of a whole discipline (e.g., history, physics or psychology) while all other subjects are complex, because they require combinations of more concepts (like the history of England in the 20th century) for their designation.


The reason for this use of the concepts simple and complex is connected to the basic idea of facet analysis. Disciplines are analyzed into facets, in logically exclusive and exhaustive dimensions such as time and place. These dimensions are the elements with which the classificationist is working. In the concrete subject analysis he combines the subject-designations by these elements. The subjects that have the smallest conceptual extension because they are delimited by more facets, becomes more complex subjects compared to subjects which are not delimited this way. 


To Ranganathan a concept such as "gold" cannot be a subject (instead he terms it an "isolate"). This has been criticized by Metcalfe (1973, p. 318). The question is thus if Ranganathan's terminology is more confusing than clarifying? In the examples given above it is only the subject designations that are more complex, not the subjects themselves. The concept "history" has an extension that is larger than "The history of England" which is again larger than "The history of England in the 20th century". This last expression is thus a wider and more complex subject. Only in the meaning of "composed of the facets time and place" may "England" be regarded less complex than "The history of England in the 20th century".





Byström, K. (2002). Information and information sources in tasks of varying complexity. Journal of the American Society for Information Science and Technology, 53(7), 581-591.


Germonprez, M. and Zigurs, I. (2003), “Causal Factors for Web Site Complexity,”
Sprouts: Working Papers on Information Environments. Systems and Organizations, Vol. 3,


Langridge, D. W. (1976). Classification and Indexing in the Humanities. London, Butterworths.

Metcalfe, J. (1973). When is a Subject not a Subject? IN: Towards a theory of Librarianship. Ed. by Conrad H. Rawski. New York: Scarecrow Press.



See also: Specificity

Birger Hjørland

Last edited: 14-02-2006