The PLE's premise is that , in performing tasks (e.g., writing or speak-ing) individuals adopt a course ofaction that will expend the probable least average of their work the least effort. Many proposition s can be derived from the basic premise. One example (anong several dozen offered by Pool, 1985) is this : "Information channel use is a function of user awareness." A number of empirical studies have found that, as knowledge of a source, it's potential contents and capabilities increases, the use of that they have used in the past in strong preference to trying out new sources of information.