Development and Validation of an Instrument for Assessing Users’ Views about the Usability of Digital Libraries

Introduction A digital library is a blend of "(1) a service; (2) an architecture; (3) a set of information resources, databases of text, numbers, graphics, sound and video etc.; and (4) a set of tools and capabilities to locate, retrieve and utilize the information resources available" Borgman (2000, p. 41). Watstein, Calarco, & Ghaphery, (1999) reported that terms such as virtual libraries, on-line libraries, and electronic libraries are used simultaneously and/or interchangeability with the term digital libraries. The Association of Research Libraries (ARL) has suggested a definition for digital libraries that was advanced by Drabenstott (1994). This definition consists of elements that are common to terms used to explain digital libraries. These elements are: * The digital library is not a single entity; * The digital library requires technology to link the resources of many; * The linkages between the many digital libraries and information services are transparent to the end users; * Universal access to digital libraries and information services is a goal; and * Digital library collections are not limited to document surrogates: they extend to digital artifacts that cannot be represented or distributed in printed formats. Digital libraries are increasingly becoming a part of the digital learning communities, in particular, distance education. Roes (2001) stated that digital libraries are natural complements to electronic learning settings. Digital libraries have many benefits such as bringing information to users; providing enhanced searching, sharing; collaboration, and use of information; and lessening the digital divide (Arms 2000). McCray & Gallagher (2001) stated that designing a usable system is one of the major principles in developing digital libraries. The authors believe that characteristics such as accessibility, simplicity, user control, and clear navigation should be incorporated into the design for usability of digital libraries. Usability is generally characterized as the determining aspect of a product or system's capability to satisfy the needs and specifications of users. Usability is the extent of how users easily and effectively use a product or system. It plays a vital role in user acceptance of a product or system (Dumas & Redish, 1993; Guillemette, 1989; Holms, 2002; Nielsen 1993; Nielsen, 2000; Rosenbaum, 1989; Rubin, 1994; Shackel 1991). A digital library is a system that must be usable. Much of the literature in the area of usability of digital libraries has been on testing and evaluation (Dickstein & Mills, 2000; McGillis & Toms, 2001; McMullen, 2001; Walbridge, 2000). A critical, yet largely unexamined facet of usability of digital libraries is the users' views of the usability of digital libraries. Research has acknowledged that users' views play a vital role in determining the usability of digital libraries (Blanford, Stelmaszewska, & Byyan-Kinns, 2001; Covi and Kling 1997). One's behavior based on his or her views about the usability of digital libraries may play an important role in the success of learning in general. Therefore, this study attempted to develop and validate an instrument that measures users' views about the usability of digital libraries. Users' views may serve as the major intermediary to user acceptance and satisfaction, thus promoting positive learning experience. Development of the Instrument: Content Validity The literature has documented many usability attributes that are the end result of a usable product or system. In general the following usability attributes are reported in the literature: effectiveness, learnability, flexibility, and attitude (Shackle, 1991); learnability, efficiency, memorability, errors, and satisfaction (Nielsen, 1993); effectiveness, efficiency, and satisfaction (ISO 9241-11, 1998); and understandability, learnability, operability, and attractiveness (ISO 9126-1, 1991). …