as a searcher, or their level of subject expertise. Also, this theory takes into account the user's previous information-seeking experience. The user will use the tools that are most familiar and easy to use that find results. The principle of least effort is known as a "deterministic description of human behavior".

The principle of least effort applies not only in the library context, but also to any information-seeking activity. For example, one might consult a generalist co-worker down the hall rather than a specialist in another