In order to ensure enhance system usability a system

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: sured as part of a study to measure other usability elements. In order to ensure enhance system usability, a system should have very low error rate, so that users make few errors during system usage. In addition, catastrophic errors must not occur. (Nielsen 1993) System users should try to control system error as much as they can. Some errors can be corrected right away by the system users, without any effects other than to slow down the transaction time. Such errors don’t need to be counted separately, since their effects are included in the measurement of efficiency of use. (Nielsen 1993) 2.3.5 Subjective Satisfaction: According to Nielsen (1993) subjective satisfaction refers to the extent the system is pleasurable to use. User likeness is critical for system success; therefore the system should be pleasant to use to achieve subjective satisfaction. Since, the subjective satisfaction is an important usability attribute for the systems that are used on an optional basis in a non-work environment such as computing games, interactive fiction and creative painting. In such systems the entertainment value is significant as compare to its speed to do things get done. Users should have an entertaining, dynamic and continues enriching experience when using such entertainment systems since they have no other objective. Subjective satisfaction being a usability attribute is different from the issues of the general public’s point of view about computers. People’s point of view toward computers in general should probably be seen as a component of the social acceptability of computer instead of their usability. Subjective satisfaction can be measured by merely taking the users opinion about the subjective satisfaction of any system. From single user perspective, the answer to such a question is subjective, however when answers from multiple users are averaged together, the result is will be objective measure of the system’s pleasantness. Since, the entire purpose of subjective satisfaction usability attribute is to measure whether users like the system or dislike, it is very suitable to measure it by asking the users. (Nielsen 1993) 2.4 Usability and System Acceptability According to (Nielsen, 1993) system usability is relatively a minor concern as compared to the larger issues of system acceptability, which is the main question of whether the system is good enough to satisfy user needs and requirements and other potential stakeholders e.g. users, clients and managers. In general, acceptability of a computer system is again a combination of its social acceptability and practical acceptability; for instance, consider a system which investigates whether people applying for 21 unemployment benefits are currently employed or unemployed to prevent fraudulent claims. This can easily be done by verifying information with other systems. Some people might appreciate this fraud-preventing system whereas some people might assume that it un-necessarily delays the benefits to deserving people. In this example, the system is not socially acceptable by peoples of later category; even though the system is practically acceptable since it prevent fraudulent claims. According to (Grudin, 1992) if it is decided that the system is socially acceptable and satisfied, we can proceed to analyze its practical acceptability within various categories, including traditional categories e.g. cost, support, reliability, compatibility and system usefulness. Here, system usefulness refers that the system should be able to achieve desired objectives. In addition, it can be split into two groups as utility and usability. Here utility refers to the question whether the functionality of the system mainly can do what is desired and usability refers that how well users can use that functionality? According to Mulligan (1998) usability applies to all aspects of a system with which a human may interact including installation and maintenance system procedures. It is uncommon to find a computer feature that really has no user interface components. Even a system facility to transfer data between two computers will surely have an interface to trouble-shoot if any error occurs. ______________________________________________________________________ ______________________________________________________________________ Figure 2.2 A model of attributes of system acceptability Source: (Nielsen, 1993) Page 25 22 In this figure 2.2., A model of attributes of system acceptability is given which illustrates the different elements of system acceptability. The model is based on four key attributes, included social acceptability, practical acceptability, usefulness, utility and usability, these elements are critical for the successful interface design. The main features of system acceptability also include sub-elements that describe the details against each key segment. 2.5 Principles to support Usability Dix et al.,(1993) have defined general principles which can be useful to the d...
View Full Document

Ask a homework question - tutors are online