The rapid establishment of third-generation distance learning environments, the so-called Web-based or tele-teaching environments, is nowadays a fact. The main means for the delivery of this new educational approach is the World Wide Web, and there are some good reasons for its use, such as its easy accessibility by many groups of learners. It also supports multiple representations of educational material and various ways of storing and structuring this information, as well as being powerful and easy to use as a publishing medium. Additionally, it has been widely accepted that the hyper-medial structure of the Web can support learning. Some researchers characterize the Web as an active learning environment that supports creativity. In addition to this, the Web encourages the exploration of knowledge and browsing, behaviors strongly related to learning. The associative organization of information in the Web is similar to that of human memory, and the process of information retrieval from the Web presents similarities to human cognitive activities (Tselios, Avouris, Dimitracopoulou, & Daskalaki, 2001).
Learnability And Usability
To define the notion of “learnability,” we must first answer the question, “What makes the (instructional) content of an environment easily learned?” The answer to this question defines in general the learnability of the environment. A more formal definition attempt would be the statement that it is the set of methods, modes and tools of the environment that facilitate the acquisition of knowledge. This work assumes that the notion of learnability embeds de facto the notion of the communication channel; it is impossible for someone to gain knowledge if the environment lacks the means to offer it. So, an evaluation of the learnability of the environment therefore evaluates the success rate of the established communication channel. Continuing on, the next question that emerges is the relation between usability and learnability, and to what extent one affects the other, which is a central question in this chapter. In more detail, we are interested as to whether a usable environment facilitates the acquisition of knowledge, or the opposite – whether a less-usable environment creates certain obstacles. Finally, this question transforms in the question if one can heuristically assess the learnability of an educational environment. Heuristic evaluation, as described initially by Nielsen & Molich (1990) and followed by Nielsen (1993), is a well-established expert-based interface method for evaluating the usability of a particular interface. A set of interface experts is asked to judge the interface based on a set of a few criteria, the heuristics.
What do we mean by the term “usability”? According to the ISO-9241 (ISO, 1998) standard, we have the following definition: The usability of a system is its ability to function effectively and efficiently while providing subjective satisfaction to its users.
The usability of an interface is usually associated with five parameters (ISO, 1998; Nielsen, 1993), derived directly from the above definition:
Key Terms in this Chapter
Learnability: The degree to which a system can transfer knowledge in a natural way. “Natural” in this context is the way the user is used to acquire the knowledge.
Heuristics: Rules or criteria that derive directly from practice. Usually they are not scientifically proven, yet they are broadly acceptable.
Empirical Evaluation: Evaluation methodology that employs users to interact with the system.
Expert-Based evaluation: Evaluation methodology that employs experts, mostly from different cognitive domains, to assess certain system aspects.
Educational Evaluation: Assessment of the educational value of a piece of educational software.
Usability: The ability of a system to interact naturally and transparently with its users. “Naturally” in this context is the way the user is used to act and “transparently” means not interfering with the performed task.
Constructivism: An educational theory arguing that students construct their own knowledge on the domain, rather than acquiring certain behaviors on how to interact with it.