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The Digital library


The definition of the digital library ranges from being seen as a single library digitizing its collection, to immediate user access to all the digital information and services that the internet can provide. It encompasses notions of both a place providing resources to a community, as well as a distributed network (Leiner, 1998). Xie reiterates this fundamental definitional dichotomy of access and content retrieval on the one hand and the collection, organization and associated services on the other (Xie, 2006). Rasmussen similarly recognises this split between content in the broader digital world and the library’s focus on functionality and service (Rasmussen, 2004).


In seeking expansion beyond the OPAC and locally hosted databases, the digital library stresses externl linkages beyond its own collections. It places information objects to the forefront and reiterates as a priority organization and access to those objects. Collections, by not being limited to individual holdings or formats, places the digital library within (and importantly beyond) the boundaries of the traditional library. The transition from custodian, collector and controller towards an enabler of immediate access and the dissemination of information in all its formats, forms the catalyst to new digital hybrid library (Chowdhury, 2004). This library, as a bridge between the conventional and the fully digital, forms a useful model for how academic libraries in particular are re-aligning. From local digitisation projects to remote database access via standard protocols, the new digital library landscape shifts towards the one stop shop of seamless connectivity and interoperability with the user firmly centre stage (Chowdhury, 2004).

User focus in the digital library

“When designing a DL, the starting points are its intended usage and the corresponding user needs” (Fuhr, 2007, p. 21).

There is recognition that access to online databases, e-journals and books is now a requisite expectation of academic libraries (Kaur, 2007), with facilitated research assistance for clients a primary staff function. The jump from database management to meeting multiple user needs lies in the acceptance that information requests and provision are not static. Instead, they reflect a system design response to an amorphous clientele’s information needs in a changing environment (Carr, 2006).

No two people search identically. Knowing what to find, exploring, not knowing what your looking for and re-finding items are accepted modes of information seeking web design principles (Spencer, 2006).

Chowdhury notes various factors affecting user searching (for example, working conditions and past behaviour) whilst acknowledging the digital libraries’ responsibilities to know its users (Chowdhury, 2004). The best design of user interface for digital libraries can be built on search behaviours ranging from simple queries and advanced searches, to skimming and surfing multiple platforms utilizing weblog evaluation, surveys and feedback as a shaping influence. Recent expectations of more remote access, keyword functionality and audio-visual accessibility can then be incorporated in future designs (Beaumont, 2002).

Davis offers three influences to consider in user interface design (Davis, 2006). Firstly, the immediate context of the users inform areas such as vocabulary design or emphasis on the commonality of keyword default word pairing (Beaumont, 2002). Secondly, the quality of the resources is supported by multiple reviews of items. This implies strong indexing control supported by a search interface that is weighted towards probability of relevance. The third point Davis challenges is sorting through the breadth of web content. The web’s size, growth, format, currency and ownership are some of the factors users experience via standard search engine searching (Chowdhury, 2004). Expectations of similar search functionality informs digital library user interface design in terms of rankings, immediacy, speed and simplicity of search, either via natural language, pairing or advanced boolean commands. This triage model of user, interface and web interaction reinforces the importance of access methods and navigation tools, with an intelligent interface able to ” provide context-sensitive help, such as feedback messages or clues suggesting a next move” (Wang, 2000, p. 234) .

Usability of a digital library connects to the ease and flexibility of use for clients, ranging from the novice to the expert (Rowley, 2000).

The process from a user’s notional need for information, to their ease of searching, to reviewing results and then refining them, forms the interface template (Chowdhury, 2003). Visualisation techniques such as icons, framing, colour, panelling and panning informs much non-textual informational representation. Design features underline standards such as shortcuts, feedback mechanisms, modification of parameters and structure sequencing. This last point relates to exponential growth of data requiring an intuitive user front end and the ability to condense information down to specific retrieved items (Adam, 1999). In recognising the variety of user and catering for all possible behaviours, the interface is the flexible portal to interaction between user and content.

Usability studies and what they show

The digital library manages relationships between content and presentation to the user. It remains axiomatic that if users don’t feel comfortable or at ease with the interface, they won’t access the information. As daily interaction with digital libraries becomes more frequent, the significance of understanding client behaviour as a factor of usefulness becomes more critical (Mardis, 2008). Ease of use, flexibility in search options and visual appeal are some of the enhancements that compliment an individual’s connectivity to and acceptance of the interface. Client interactivity with the process of faster and accurate recall can be seen as an improved personal experience. Under-scoring all is the fact that query to term matching quality as well as collection quality remain central to any system efficiency (Wacholder, 2006).

Common methods to assess client usage of a digital library include logfiles (for example browse versus keyword search choices), focus groups, surveys and scenario testing (for example, before and after webpage designs) (Clark, 2002). Beaumont’ study of the State Library of Victoria’s catalogue revealed user preference for hyperlinks over drop down menu boxes (Beaumont, 2002). She noted the prevalence of keyword search choice over browse options. Jones’ study of the New Zealand Digital Library supports this view of the default simple query type preference ( Jones, 1998). This simple search option utilizes both simple pairing and Boolean retrieval logic (Mizera-Pietraszko, 2007). It is indicative of a shift both towards greater one stop federated searching and associated citation (Dietz, 2004). It supports research reflecting a preference for simple query submissions (for example length of query strategies or default query fields) (Dietz, 2004).

The Washington Research Library Consortium chose open source software to build its digital collection. In dealing with an ever-changing diverse user clientele noted that “the user inter- face had to be easy to navigate and easy to customize” (Zhang, 2006, p. 73). Direct links to objects, cross- searching capabilities and multiple image display were noted as mandatory interface features. How the user navigates a webpage and the way information is displayed accepts openness to flexibility in design and user feedback. The 2006 SEKT project of managing scientific networked metadata reinforced ontological keyword searching as an accepted requirement (Warren, 2005). The ability to relax and tighten searching strictures can then be mapped to a user’s personal profile.

Drifts towards this mix of both manual and automatic search approaches is indicative of stronger semantic web technology (Antoniou, 2004).

The digital library is an assemblage of data, practices, knowledge and users which necessitates compromises within its working infrastructure (Bishop, 2000). Minor system design issues or tweaks can be a major user concern exemplified in quick exit from the system. The University of Illinois’ analysis via user metrics, observation and usability testing suggested online viewing of articles over browsing features. Immediate viewing from the desktop was rated above an interface’s extended search and display options. A heuristic analysis (or checklist approach) informs Blandford’s conclusion that system developers need to understand how users think (Blandford, 2004). In examining digital databases like Ingenta, discussion fell on the uer’s cognitive walkthrough process and that “to assess the usability of digital libraries, knowledge of DLs and their users is essential “(Blandord, 2004, p. 34). Finally, Jeng’s usability model considered 24 digital libraries. The interface can be summarised as requiring effectiveness, efficiency, satisfaction and user learnability with ease of use, organisation, labelling, visual appeal, content and error correction as essential features (Jeng, 2005) .

What a digital library should have

Xie lists the main interface usability criteria as:

– Search and browse options

– Navigation tools

– Help functions

– View and output

– Accessibility

(Xie, 2006, p. 440).

The ability for users to both browse topics as well as use a variety of search options (from simple to advanced) is one standard of digital libraries. Full text searching is based on metadata items within indices (e.g. subject headings). As such, these can be further expanded or restricted by format, currency, language and other parameters. Based on how the metadata is manipulated, sorting and browsing alphabetically or by date are just two common approaches. Digital library design necessitates sets of search criteria of controlled vocabularies matched against what has been indexed and therefore, is retrievable (Davis, 2006). Displaying results and the ability to sort, save searches, modify and customise are requisite functionalities (Chowdhury, 2004). Zhang’s study comparing browse to search choices within the ACM digital library revealed that with:

* Searching- User frustration at too many zero hits, poor result display and lack of feedback, and

* Browsing -Too many clicks and lack of navigation tools (Zhang, 2008).

Interface design is based around understanding the users’ needs and enabling action. Clear visibilities matching the expectations to the results, offer the further granularity that is often desired. Query refinement is a common user activity (Jones, 1998). In recognising that digital library users seek the easiest path via consistent frameworks and simple shortcuts, the interface assumes a palette requiring free typing space in the search box, quick alerts of user mistakes and possible alternative layouts depending on the type of user. This approach blurs the need for the user to distinguish between browsing and search options.

The context can reinforce the perception by the user of the resource as an quality educational resource (Davis, 2006). Aesthetic design is noted by Norman as being considered more important in user preference than operational functionality (Norman, 2004). Hartman lists the five aesthetic criteria of a website as usability, content, format, reputation and customisation with “more engagement” with the interface (Hartmann, 2007, p. 13) , noted as the principal preference for continued usage. Standards surrounding navigation tools, beyond the simple to expert options, include minimized scrolling and jumping as well as anchoring in consistent previewed results (Marchionini) . Help functions are a standard available feature, moving from FAQ screens to automated widgets to communities of practices and online assistance.

Digital libraries are based on distributed connectivity to other systems embodying a new notion of collection access rather than ownership. As such standards such as Z39.50 protocols and ability to function on various browsers are accepted building blocks. Accepted prerequisites are searching, sorting, selecting and manipulation of objects based on the embedded system’s data and metadata (Arms, 2000). Additionally, offering short-cuts and simple controlling options are basic assumptions that any digital library must have.

The invisibility between the task of searching and the tools required is becoming more common. On the other hand, the lack of a human intermediary in information search requests pre-supposes system design covering all types and levels of user search behaviour from the serendipitous to the advanced (Chowdhury, 2003). Given the decentralised nature of web information, the challenge remains to offer a flexible interface while still controlling the quality, organization and retrieval of the content (Logoze, 1998).

What a digital search interface could have Shifting from menu and command driven information retrieval to natural language processing is accepted as a standard enhancement of today’s digital library. What the user wants (or thinks they want) and linking this to a controlled system vocabulary becomes possible via thesauri which can deal with slang, mis-spellings and compounded terminology (Chowdhury, 2004). Natural language searching implies acceptance of any term but supposes higher recall and lower precision in search results (Lancaster, 2003). Natural language functionality involves both auto-indexing (words to text) and auto-abstracting (term frequency, weighting, clustering etc) (Browne, 1996). For the average user, underlying the displayed results is the balance between comprehensive index list coverage and term specificity.

Chowdhury suggests the future of digital library user interface includes:

* The ability to searching and browse other digital library collections.

The changing nature of metadata (from MARC and AACR2 to for example, XML or SOAP to Dublincore standards) has shifted to a human readable format that is a faster multi-formatted cataloguing strategy (Reese, 2008).

Protocols allowing connectivity to other collections beyond the immediate interface allows users to recognise what they consider important beyond their initial information request (Frost, 2000) .

Seamless browsing across digital collections increases recalled results and finds suitability for less experienced users (Chowdhury, 2004).

* Peer consultation.

Bulterman highlights the use of interactive peer group annotations to enhance the information inside a base document (Bulterman, 2003).

Digital libraries as e-learning platforms can offer interaction between users, instruction and content (for example, chat services) as well as online instructional tutorials. Similarly, collaboration between digital library designers, educators, librarians and students informs educational course design allied to teaching and learning objectives (Sharifabadi, 2006).

* Visualisation of data.

Digital libraries offer immediate multimedia and multilingual distribution of rich content. Strong visual interface design is linked to human perception, spatial vision and slower reading capabilities and the need for rapid access, sharing and collaboration (Kang, 2000)

Features have developed from earlier thumbnail and zooming displays to interfaces that include filtering, multi-perspectives, federated searching, personal storage baskets amongst others.

Future developments include plural visualisation tailored to types of user behaviours and semantic scene matching to geographically tagged databases like Flickr.

Hays, J. (2008). Scene completion using millions of photographs. Communications of the ACM archive, 51(10), 94

* Reviewing session histories.

The wider concept of digital libraries as connections between collections, users, services and the technologies envelops users being able to review their past searches. The ability to personalise space and recommend results is seen as a long term development beyond existing algorithm construction (Smeaton, 2005). Book marking via links to tagging software like Delicious, as well as managing search suggestion pop-ups, are expected user interface enhancements.

6 digital library case studies

Basic user interface functionality splits between relevant ranked output, searching capability and subject connectivity (Antelman, 2006). In achieving best results in technical design, understanding user behaviour is critical. Ferrara comments that search behaviour is dependent amongst others on cognition, technical expertise and style (for example, how people skim results or make quick judgments) (Ferrara, 2009). Each of the following five digital library examples provides sufficient user behaviour scope in exploring developments in search interface design.

* University of Patras, Greece: e-journal service

It is recognised that the user’s judgments of online content is a critical consideration in interface design. Navigating the increasing breadth and width of internet resources depends more and more on the conduit established between technical improvements and the apparent ease of user application. Monopoli noted that users “tend to adopt a relatively unsophisticated, simplistic approach to searching” (Monopoli, 2002, p.105). The lack of use of online help confirmed an assumption that users are reluctant to try something different until they are comfortable with what they already know. Monopoli’s investigation found keyword use (often singularly expressed) out-weighed other preferred methods, for example author searches. Use of Boolean operators was limited, Underlying this is (and invisible to user activity associated with the interface) is support for concepts like boolean query weighted specification types based on users past preferences (Tsinaraki, 2006).

Stephanis similarly noted that users don’t need to understand the query language or how data structures operate (Stepandis, 2009). Instead they are interested in a suite of contexts that overlap what they are seeking and then base a further refinement on the results that have been presented to them. It offers further strength to Semeraro’s recent research into keyword searching and matching it to user likes and dislike profiles based on binary text classification (Semeraro, 2007).

* Chi Nan University Digital Museum system

Extending the standard concept of a digital library to include edutainment modules like interactive games, hypermedia

presentations and user commentary on digital content, is the theme of Chi Nan University digital museum’s development. An integrated user environment that best replicates in a real sense their connection virtually is shaped by aesthetic criteria, as much as by the necessary media and metadata configurations.

Their focus on preserving data on butterflies is grounded on:

* XML based content (cognisant of both full text and attribute searches)

* Content based image retrieval (for example, how a user describes pictorially the butterfly he wants to retrieve can be searched by either features or examples)

* Multi-media exhibits

* Interactive experiential learning

* Natural language FAQs based on a keyword matching algorithm

* Online instruction on butterflies

Hong, J. (2005). Toward an integrated digital museum system- the Chi Nan experiences. International journal of digital libraries. 5, 234

This digital museum project provides evidence of adapting the style of a webpage to user preference and the necessary compromises between the content, aesthetic design and the technology (Hong, 2005)

* EBSCO Federated search interface (Released October 2009)

The ability for the user to search across digital collections is increasingly becoming a feature of enhanced functionality. Linking software (such as SFX and Serial Solutions) that enables

connectivity to non-proprietary vendor platforms, is being replaced by administrative consoles that allow librarians to setup access to any database from any vendor. This allows home library customisation to occur. EBSCOhost integrated search publicises its improved user functionality (for example, publication clustering, adding to personal folders or date limitation slide ruler) and tiered result display (that is, a ranking pre-determined by the librarian).

* Westlaw and LexusNexus law databases

Jones suggests that browsing relies on familiarisation and improved vocabulary, whereas searching is more quantifiably result driven, often without proper context. In both cases, clicking occurs frequently with the human eye scanning “the top left, mid-left, and centre of the screen” (Jones, 2006, p.12). In designing a user interface for a specialist resource, understanding screen layout, tabs, scrolling choices, highly visible links and more are critical considerations to ensuring best user access. Jones comments that navigation tools, generally at the top horizontal space of a page, were more popular. Larger fixed graphics offered similar appeal. It confirmed Outing’s important eye track experiments which showed the human eye:

* Positioned top left, then right, then down a webpage

* That larger font produced more scanning

* That eyes concentrated more on the fist two words of a headline

* That sight focuses on the lower portion of a screen seeking something of more value

* That standard one column layouts attracted more concentration (Outing, 2006).

Search behaviour is affected by interface design such as font, grouping, layout, density, simplicity and more. Ngo lists 8 criteria for screen design model ranging from balance, equilibrium and unity to economy and order (Ngo, 2001). This supports Tractinsky’s thesis of the link between a user’s perception of an interface’s appealing aesthetics and its usability (Tractinsky, 2000).

* Greenstone Digital Library software

The organization and distributed linking of metadata is a defining characteristic of digital library collections. The ability of users to customise collections according to both a preferred document format and in their preferred searching language is a feature of the Greenstone software. Customisation is possible because the interface enables users to subliminally organize hierarchical structures to their preferred presented format, with metadata values remaining nested in a defined grouping (Whitten, 2003). Similarly, multiple language conversion on translation pages is possible because each language, phrase and word is stored as metadata and the software imports macro files that match up the language strings (Bainbridge, 2003).

Zhang, A. (2006). Building Digital Collections Using Greenstone Digital Library Software. Internet Reference Services Quarterly. 11, 2, 71-89.

* SirsDynixi Enterprise 3.0

Digital library interfaces are being designed and marketed as similar in feel and approach to popular internet search engines. Look, toolbar positioning, natural language capabilities and consistent look are some features of eBay, Ninemsn and Yahoo that resonate with users, beyond their content (Lodge, 2006). SirsiDynix, in promoting its system as a one-stop shop of catalogs, RSS feeds, virtual reference, databases and more, pushes the concept of a simple user discovery portal far removed from traditional separate search interfaces (Fleming, 2005). The creation of high quality web 2.0 subject content in virtual rooms is analogous to the LibGuides product. Recently, distributed content via widgets and applications to websites, forums and educational learning management systems is a natural extension of connectivity to the user no matter where they are and what they are using.

Fleming, P. (2005). Sirsi Enterprise portal solution featuring Rooms 2.0. SirsiDynix One source, 1(2),1.

Matching user search behaviour to the Sirsi interface has produced features such as:

* Single search box, because users already know how to use Google (Newton, 2007).

* Results that use fuzzy logic or trigram analysis to discount search mis-spellings, mistakes or diacritics.

* “Did you mean” suggestions based on catalogue indexing terms (Abram, 2009).

* Back button web browser enablement

* Dynamic search suggestions based on past user experience (SirsiDynix, 2009).

* Harvested searching, or the ability for users to gather information regardless of document type or its location

* User ranking, tagging and reviews

* Search widgets (piece of code that can be embedded into other webpages) (Arnold, 2008).


The needs of the audience in terms of usability informs digital library search interface design. Simple search boxes, use of their own keywords and seamless connectivity all refocus the search within the context of the user (Proffitt, 2006). Best practice development will be guided by flexibility in design, integration of searching and browsing, natural and multiple language capabilities and clear result presentation amongst others (Davis, 2006). Digital visibility as much as efficient content retrieval will shape a user’s evaluation of a digital library. Factors such as access, currency and interactivity will combine with the modern library web searcher’s ability to “bounce and flick” (Nicholas, 2004, p. 32) in seeking information.

The typical expectation of a digital library’s searching functionality is the immediate response of relevant yet comprehensive information, all presented seamlessly via a consistent yet flexible interface (Bawden, 2006). In the age of the web search engine, digital libraries need to do more than provide quality resources (Lagoze, 2005). The challenge will be to add value to this content via better user profile analysis, collaborative contexts and interface design.

Paul Kloppenborg

LRC Manager (William Angliss Institute) – Melbourne, Australia



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