Our research model uses the principle of least effort to investigate and explain how physical and mental access to books increases circulation.
What is the Principle of Least Effort?
Library of Congress research librarian Thomas Mann surveyed 22 studies revealing that professors and scientists in all disciplines, engineers of all types, medical doctors, etc. “will tend to be satisfied with whatever can be found easily in preference to pursuing higher-quality sources whose use would require a greater expenditure of effort.” (- from chapter 8 of Library Research Models, 1993, p. 91)
Physical access to books is defined as "ease with which patrons can see and reach the books." The greater the ease the greater the physical access. The essay "Physical access to books" presents experimental evidence demonstrating the ways that ease of physical access increases circulation.
Mental access to books is the "ease with which patrons can select which books to check out." The easier it is for patrons to select books the greater the mental access. The essay "Mental access to books" presents experimental evidence demonstrating the ways that ease of selecting books increases circulation.
The phrase "mental access to books" originated from Sharon L. Baker's experimental exploration of how "information overload" creates difficulty in selecting books from library shelves containing thousands of books. Since the phrase "information overload" refers only to this difficulty, I use "mental access to books" to think about and discuss situations where selection is difficult and situations where selection is easy for any number of reasons, not just the presence or absence of information overload.