BROWSING IN A BOOKSHOP HAS A DIFFERENT OUTCOME THAN A ONE-CLICK SEARCH. An Amazon search for a subject usually gives you a relatively narrow set of results. By contrast, browsing randomly in a bookstore leads you to many unexpected places. Linear research may be likened to the Amazon experience — you generally find what you are looking for; by contrast, nonlinear research methods can lead to the unexpected. If you have the leisure, the latter path may yield the greatest treasures.