Just as Hansel and Gretel created a breadcrumb trail to find their path back home, today’s internet user often finds a need to get back to a website’s previously visited locations; hence, the cyber “breadcrumb trail” was created.

Usability News - 5.1 2003 -- Breadcrumb Navigation: An Exploratory Study of Usage
In general, breadcrumbs serve two purposes: 1) they provide information to the user as to where they are located within the site, and 2) they offer shortcut links for users to “jump” to previous categories in the sequence without using the Back key, other navigation bars, or the search engine. Breadcrumb paths give location information and links in a backward linear manner. Navigation methods, such as search fields or horizontal/vertical navigation bars, serve to retrieve information for the user in a forward-seeking approach. As suggested by Marchionini (1995), systems that support navigation by both browsing and analytical strategies are most beneficial to users since various patterns, strategies, tactics, and moves associated with both types of strategies are normally used.

Breadcrumb trails, according to Bowler, Ng, and Schwartz (2001), help users browse and search for information, as well as provide paths back up the web hierarchy. Toms (2000) found that the search tool was most useful in focused searching; while menus were considered essential for browsing. She also suggests that users need both a stable orienting device, such as a menu, to facilitate pathways through the site, as well as a system that supports scanning to smooth the progress of the search (Toms, 2000). However, research on breadcrumbs as a navigation tool has been limited. Studies researching breadcrumb navigation have used simple site structures in a controlled experimental setting. These studies found that the availability of breadcrumb navigation bars resulted in more efficient site navigation and satisfaction (Bowler, et al. 2001; Maldaonado & Resnick, 2002).

In an attempt to better understand how, when, or even if, users use breadcrumb navigation in a real-time online environment, we conducted an exploratory study to determine if participants use breadcrumbs when given a list of items to find on a website. In addition, we were interested in monitoring what other navigational methods they use to access information or e-commerce items (i.e., Back button, navigation bars, search).

In this study, we evaluated participants' navigational strategies, user satisfaction, and general preference for two sites that utilize “breadcrumbs” – Google Directory directory.google.com, a web information search site, and Office Max www.officemax.com, an e-commerce office supply site. In addition to breadcrumb navigation, the Google directory (Figure 1) is organized in main and sub-categories and offers search capability.

Participants using Office Max (Figure 2) also had access to a breadcrumb navigation, search, a hierarchical left side vertical navigational structure, and a top of page horizontal navigational bar.

Participant performance was measured by the number of clicks, Back button selections, searches, and time to complete the ten tasks.…
http://wsupsy.psy.twsu.edu/surl/usabilitynews/51/breadcrumb.htm