1.1 Background to the Study
The world has become a global village where information technology is used in all spheres of human activity to record, store, and disseminate information in the digital form. The new generation whose demand for information is insatiable is always demanding that traditional libraries be developed as a well-equipped and interconnected as digital libraries. Information and Communication Technology has revolutionized the concept of libraries such that libraries are gradually becoming digitized. A digital library comprises digital collections, services and infrastructure to support lifelong learning, research, scholarly communication as well as preservation and conservation of our recorded knowledge. It is also a process of democratization of information.
According to Arms (2012) a digital library is a managed collection of information with associated services where the information is stored in digital format and accessible over a network. A digital library is an organized collection of digitized material or it’s holding in the digital form, which can be accessible from digital devices on the network using Transmission Control Protocol/Internet Protocol (TCP/IP) or other protocol. In digital library high speed optical fiber are used for Local Area Network (LAN) and the access is over Wide Area Network (WAN) and provide a wide range of Internet based services including audio and video conferencing and others. Lynch (2013) opined that digital libraries provide users with coherent access to a very large, organized repository of information and knowledge.
According to the Berkeley Digital Library Project, University of California (Wilensky, 2012), the digital library will be a collection of distributed information sources. Some of the requirements for digital libraries are: Audio visual (T.V, V.C.R, life theatre and D.V.D), Computer, Network connectivity, Printer, Scanner, Storage devices, Software. Digital libraries have features such as: Incorporating learning and access, provides fast and efficient access to information, with multiple access modes, collections which are large and persistent over time, well organized and managed. The purpose of Digital Library is to expedite the systematic development of procedures to collect, store, and organize information in digital form, promote efficient delivery of information economically to all users, encourage co-operative efforts in research resource, computing, and communication networks, strengthen communication and collaboration between and among educational institutions and take leadership role in the generation and dissemination of knowledge. Digital libraries are getting famous for flexibility of use and more users can be facilitated at a time. As numbers of users increases, some issues relevant to interaction also arise while using digital libraries interface and utilizing its e-resources.
Usability is an important aspect of evaluating applications. Usability standards should be followed by the websites designer that supports user’s confidence level and interest when interacting with the website. Interactivity is a basic principle underlying the satisfactory behavior of the system by the user. System constraints are basic conditions to operate functionalities that integrate different services and sources in one interface that displays to develop interest of users. Searching of information is an important perspective where usability is of high relevance for user satisfaction. The interface is an important part in every system because this is the part where the user directly interacts with the system and utilizes services offered by the system. In every system, usability is a reverse procedure which means it can be done at any phase of software development life cycle. Specifically, students, teachers and researchers are end users of the application and their interaction with the system shows the satisfactory behavior. It helps developers or service providers to understand how the application is used by the end users and if the system is fulfilling user requirements or not. The best way to achieve this understanding is to repeat a usability test after a period of time because it requires a lot of changes to be made in the system, and for some users those are not satisfied with the functionalities or interactivity with the system sources. Therefore, usability testing is becoming an important ingredient in different types of application.
The International Standards Organization (ISO) (2014) defines usability as “the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency, and satisfaction in a specified context of use”(p.10). Nielsen (2013) points out that usability has five attributes: Learnability, efficiency, Memorability, low error rate or easy error recovery, and satisfaction. Brinck, Gergle, and Wood (2012) share a similar perspective that usability is functionally correct, efficient to use, easy to learn and remember, error tolerant, and subjectively pleasing. In addition, Booth (2013) outlines that usability has four factors: usefulness, effectiveness (ease of use), Learnability, and attitude (likeability). Hix and Hartson (2013) classify usability into initial performance, long-term performance, Learnability, retainability, advanced feature usage, first impression, and long-term user satisfaction. The definitions given by ISO and Nielsen are most widely cited. Usability is about:
- Effectiveness – can users complete tasks, achieve goals with the product, i.e. do what they want to do?
- Efficiency – how much effort do users require to do this? (Often measured in time)
- Satisfaction – what do users think about the products ease of use?
The factors listed above is affected by:
- The users – who is using the product? e.g. are they highly trained and experienced users, or novices?
- Their goals – what are the users trying to do with the product – does it support what they want to do with it?
- The usage situation (or ‘context of use’) – where and how is the product being used? (ISO 9241-11, 2012).
Usability is used to evaluate the digital library. Usability is important because any product or system is finally dependent on users who are to evaluate it. The digital library must pass the usability test. The existing usability evaluation models have been used to evaluate digital libraries abroad. It has been considered necessary to modify model from the existing model that can meet the peculiar needs of digital libraries in Nigeria.
1.2 Statement of the Problem
System usability and system usefulness are interdependent properties of system interaction while in combination, determines system satisfaction and usage. Most usability evaluation models such as the Nielsen model, ISO model and Dix model are majorly system centered, since digital libraries are to be used by individuals there is a need for a model that is both system-centered and user-centered. Many higher institutions in Nigeria provide academic digital libraries and usability evaluation have been conducted in some of these digital libraries; however, usability evaluation has not been conducted in UNILAG, FCE(T) and LASPOTECH digital Libraries to gauge the performance of the system in context of users’ perspectives i.e. how far the academic digital libraries fulfill the users’ needs.
Also, there is a need to know if the systems are useful to its users. Since digital libraries are supposedly designed for people (as users) to use, evaluating the performance of the system is of utmost importance. Therefore, this work develops a modified evaluation model for evaluating digital libraries and will be tested by end-users (students).
1.3 Objective of the Study
The main objective of this study is to propose a modified usability evaluation model and implement it using a digital library. The specific objectives are to:
- modify Jacob Nielsen usability evaluation model;
- test the model developed in (i) using three (3) digital libraries and
- bench-mark the model against Nielsen Usability evaluation model
1.4 Research Question
- What is the usability status of a given digital library using the modified model?
- Using the modified model, how acceptable is the model developed?
1.5 Significance of the Study
This research work is considered significant as it would modify Nielsen’s usability evaluation model that would be used for usability evaluation of digital libraries. Through this research work, we would know how acceptable the model developed is and the factors that contribute to the usability of digital libraries. These factors would help us when laying down the prototype of the digital library. Information provided would be credible, reliable and useful to enable the incorporation of results obtained into decision making process of the professionals, institutions and programmers in designing and improving their digital libraries. We can also give suggestions to government, education planners and school administrators on how to improve digital libraries to meet up to standardized digital libraries. The result of this research can help programmers, professionals and academic institutions in building standard digital libraries for their respective institutions.
1.6 Scope of the Study
The scope of the project is to modify Nielsen’s usability evaluation model that will be used to evaluate usability status of digital library in any tertiary institution in Nigeria. The research also uses the developed model to evaluate the usability status of a digital library of a tertiary institution. The developed model would be tested at the University of Lagos digital library, Federal College of Education digital library and Lagos state polytechnic, Ikorodu digital library and the following usability constructs (discoverability, cognitive load, efficiency, effectiveness, learnability and satisfaction) would be used to evaluate the digital library.
We are modifying Nielsen’s usability model and it would be used to test the usability of a digital library. To achieve this, we will be using the modified Heuristic-Think aloud method.
1.8 Operational Definition of Terms
The following terms are defined as used in this study.
Usability: It is defined as the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified extent of use.
Digital library: A digital library is a collection of information and digital contents that are kept in digital formats and these are accessible to different users through computers by having access to the internet.
Internet: The internet is a global computer network that provides a variety of information and communication facilities, consisting of interconnected network using standardized communication protocols.
Modified model: It includes a combination of latent and observed variables. It allows you to integrate all available knowledge into one approach will reducing effort and maintaining accuracy.
1.9 Organization of subsequent Chapters
The chapters are organized in the following order. Chapter One contains the discussion on the general area covered by this research, the Chapter Two provides specialized overview of the literature review, Chapter Three describes the methodology used