Human-Computer Interaction: Usability and Evaluation - Report Example

?Human Computer Interaction - Usability and Evaluation Introduction Usability is one of the software elements that software designers need to take into consideration when designing a new user interface. We have all seen examples of poorly designed user interfaces at one time or the other. In all these scenarios, it might be obvious to us what the problem might be with the design, as well as what can be done to rectify the situation. Nevertheless, sometimes the usability problems might not be obvious making the correction of the errors technical to software designers. Hartson, Andre, and Williges (2003, p.145) note that usability, also referred to as human factors, or human-computer interface design or user-centered design, has become a major field of interest in both industry and academia. This is attributed to the roles computer play in the daily lives of individuals. That is, the more we need to interact with computers, the more we tend to demand well-designed software interfaces. Software developers play a crucial role in answering such demands. Designing better interfaces have quite a number of commercial merits as having been demonstrated by big companies such as Apple, IBM, Eastman Kodak, SAAB, Rank Xerox and Microsoft just to name but a few. The advantages of well-designed software include increased productivity, reduced human error, as well as making the software use enjoyable (Matera, Rizzo, and Carughi 2006, p143). Nonetheless, usability is sometimes ignored not because it is considered worthless, rather because it is considered very expensive, which is a misconception, according to experts. Software developers also sometimes ignore usability, which does not justify the cost of usability testing and evaluation. Ignoring usability in interface design has greater cost attachments, as having been demonstrated in past fatal accidents that has resulted due to the failures of interface to show vital information. One such accident occurred in 1987 when an American airline crashed during takeoff at Detroit killing 156 passengers on board (Matera, Rizzo, and Carughi 2006, p143). The accident, according to investigations, was caused pilot’s failure to recognize the wrong positions of flaps during the aircraft’s takeoff. A skilled interface designer would have proper knowledge of organize an interface in such a manner that vital information cannot be missed. This paper will explore the principles of usability and the methods used to evaluate software interfaces. Finally, the paper will evaluate an Amazon.com website in line with the usability principles. Usability design principles Adebesin (2011) argues that the interactive systems ought to be designed in a manner that supports the user to achieve his or her objectives. To do this, the design team need multi-disciplinary, with practitioners possessing ergonomics, cognitive science, and computer skills among others. This ensures that the team understands physical capabilities, human problem solving, their working environment, and the entire interaction context. A number of design guidelines are used in the software interface development. The design guidelines range from general to application-specific rules. Hartson, Andre, and Williges (2003, p.146) classify the design rules according to their level of authority and generality. According to Hartson, Andre, and Williges, the authority of design rule spells out whether or not the rules are to be followed or not. The level of generality, on the other hand, directs developers in ascertaining whether a particular guideline can be widely applied in different design situations. There are three basic principles of usability identified by Matera, Rizzo, and Carughi (2006, p.145). The first principle of usability design principle, according to Matera, Rizzo, and Carughi (2006, p145), is the principle of unity. The principle of unity in interface design is crucial since ensures congruency in the use of the interface. The unity principle also allows software interface developers to carry out all abstract things such as thinking, more easily. The principle also allows users to go into peculiar environment and be able to navigate through these unfamiliar environments without many problems. The second usability, according to Hartson, Andre, and Williges (2003, p.147), is the principle of intuitiveness. An intuitive environment gives users the fundamental principle of usability. That is the ability to navigate unfamiliar environments and make decisions without necessarily seeking assistance. Last is the principle of usability. In this regard, software interface needs to be user-friendly as much as possible. The software interface needs to be user-friendly in a manner that users can easily enter and leave without facing any obstacle or losing their way. Users should be able to find information at the exact location where they should be (Hartson, Andre, and Williges 2003, p.147). At the same time, when they leave the interface, they should feel confident that the experience was pleasant. This enables users to come back when need arises since they remember very well about the interface to use without having problems and with less hesitation than if the interface fooled them or made them feel frustrated. Usability evaluation techniques and approaches The application of usability, according to Hartson, Andre, and Williges (2003, p.150), can be evaluated through several evaluation methods. The evaluation methods used are categorized according to the involvement of the expert analyst of end users. The usability evaluation conducted through expert analysis includes heuristic, cognitive walkthrough and model-based evaluations. On the other hand, evaluations involving user participation include query methods such as questionnaires, interviews, experimental evaluations, and observations. Heuristic evaluation Heuristic evaluation involves expert analysis of whether an artifact conforms to a set of usability rules. The technique is usually considered as the general rule of the thumb used to guide a design decision in formative assessment during the early stages of development. In addition, the technique is useful when it comes to critiquing decisions made in a summative evaluation of an entirely functioning system. The method is preferred for evaluation because it is inexpensive and does not require the involvement of users. Heuristic evaluation involves the examination of an interface autonomously by evaluators and making judgments thereof on its conformity the set of heuristics. The main objective of doing this is to identify the problems of usability in the design in order for them to be rectified as part of an iterative design process (Hartson, Andre, and Williges 2003, p.150). Cognitive walkthrough evaluation The cognitive walkthrough technique originated from cognitive science theory in which expert evaluators with cognitive theory skills examines a software application by stepping through a set of tasks. The objective of this technique is to evaluate systems learnability where users learn how to use the system by examination, but not by reading the user manuals. Like in heuristic technique, the cognitive walkthrough technique does not require user participation. The method is flexible and inexpensive making it appropriate for use in both summative and formative evaluations before user testing (Daabaj 2002, p.16). Model-Based Evaluation Model-based evaluation, according to Hartson, Andre, and Williges (2003, p.152), is used for predicting the performance of users in the systems without the participation of users. In this method, expert evaluators predict the performance of users using various formulas and/or simulations of models. The main goal of the technique is to obtain some usability results before a given prototype or design is tested or implemented with the involvement of human participants. Interviews Interviews are also another technique employed in the HCI research for evaluation to establish whether an interface or a fully implemented system conforms to the user’s needs by enquiring directly from them. Daabaj (2002, p.22) claimed that an interview is a conversation involving two people, initiated by an interview for purposes of obtaining vital information. Effective interview requires proper planning by the interviewer to ensure that all interview questions are properly structured to suit its purpose. The interview may take the form of structured, unstructured, semi-structured, and focused groups. Questionnaires Questionnaires are another usability evaluation method, which involves the participation of users in the evaluation process. It is one of the basic data collection methods in HCI field due to its relative ease of administration and potential of reaching many audiences. A questionnaire involves administering structure questions through a computer or paper-and-pencil environment. The method has proved effective in measuring the subjective views of interface users on the application tested. In HCI, questionnaire is used to gather information pertaining to the users’ preferences, attitudes, and product evaluation (Daabaj 2002, p.23). An evaluation of Amazon’s website As the market place is increasingly becoming extremely competitive, organizations are rushing to integrate technologies into their business operations. Amazon.com is one of the many companies that have adopted technologies in their interface to increase usability of the site. A company’s homepage is the most important real estate in the world while websites acts as the face of the company to the external world, notes Bazeley and Ridder (2004). In this regard, a company is expected to keep updating its homepage in order to increase profitably, value, and trust of stakeholders on the company. However, using heuristic evaluation technique on Amazon.com it became evident that the company did not exhibit the information to users from its website. Nielsen (2002) argues that companies should ensure that their name is as visible as possible for the user to gain information about the company when they click on the website. For instance, Amzon.com failed to include the section ‘about us’, which is very vital for users who want to know about the company, what it deals with, and the address. According to Nielsen (2002), a website with a link for, ‘about us’ helps in directing users about the company so as to improve the purchasing behavior, public relation, building trust and recruitment among others. According to Nielsen (2002), Amazon.com’s homepage has a variety of products with compressive details of the product categories that the company sells to its customers. The company effectively categorizes its products while maintaining an uncluttered appearance on its webpage. In addition, Amazon does not use too many graphics and undersized tables on its webpage thereby minimizing the download time. This valuable feature conforms to the usability principle of usability since it increases the satisfaction level of users of the website. Nelsien (2002) reveals that users tend to avoid websites that take too long to access and never to return. However, in Amazon.com’s case, the company has developed an interface that is user-friendly and easily accessible to all users. With regard to usability, quality attributes is very important in web design. Bazeley and Ridder (2004) identified two types of web qualities namely content and design. Pack (2002), on the other hand, identified four categories of web site quality attributes namely friendliness, information, reliability, and responsiveness. Amazon.com has a webpage that satisfied all these website attributes. Amazon.com allocated the usability to three areas namely the page design, site design, and content design. However, Amazon lost some of its simplicity features since the company is selling many different items (Pack 2002). In addition, poor information architecture might lead to poor usability of Amazon’s website. Amazon.com also has homepage consisting of listed information texts and navigation bars at both the bottom and top of the page. The screen also has two screens below what the customers of the company sees upon entering the website. Instead of forcing users to scroll down on the webpage to view information, Amazon.com has designed a webpage with sharper images that fit almost all its contents and images within the screen. However, Amazon.com appears to waste the screen’s real estate by maintaining the full header in its homepage. In addition, the webpage also contains numerous links to books that are irrelevant to most users (Bazeley and Ridder 2004). Nonetheless, Amazon.com uses three different navigation bars such as ease of use, minimal download time and relevant to user needs (Pack 2002). Further, Amazon.com’s webpage has various page layouts features that enhance the webpage. The features of the webpage include color, style, text, graphics, page size, and consistency. Amazon.com use while color at the background of the page and black color text to make it simple. In addition, the company uses links with blue color texts that show gold color upon clicking indicating that it is being viewed as the user click the link. This satisfies the usability principle of intuitiveness. Conclusion This paper presented the principles of usability, and the methods used to evaluate software interface. From the discussion, it became apparent that a number of usability evaluation techniques and approaches exist that can be employed in the evaluation of software interfaces. The paper also evaluated in details Amazon.com’s interface, which according to the analysis conforms much to the various principles of usability. References Adebesin, T.F 2011, Usability, and accessibility evaluation of the digital doorway. Pp. 1-241. Bazeley, M., & Ridder, K 2004, “Amazon tests search engine, tribune business news.” Washington: Apr 15, p. 1. Proquest. viewed 31 may 2013 http://proquest.umi.com.ezproxy.utas.edu.au/pqdweb?index=17&sid=1&srchmode=1&vinst. Daabaj, Y 2002, An evaluation of the usability of human-computer interaction methods in support of the development of interactive systems. 0-7695-1435-9/02 $17.00 (c) 2002 IE. The University of Salford, Manchester, M5 4WT, UK. Hartson, H.R., Andre, T.S., & Williges, R.C 2003, Criteria for evaluating usability evaluation method. international journal of human–computer interaction, 15(1), 145–181. Matera, M., Rizzo, F., & Carughi, G.T 2006, Web usability: principles and evaluation methods. pp 143-180. Nielsen, J 2002. ‘Top ten guidelines for homepage usability.” Viewed 31 May 2013 http://www.useit.com/alertbox/20020512.html. Pack, T 2002, ‘Two experts explain what makes websites work’, Web-watch, Medford. Vol. 19(2), p. 17 Proquest. Viewed 31 May 2013 http://proquest.umi.com.ezproxy.utas.edu.au/pqdweb?index=0&did=110225331&SrchMode=1&sid=10&Fmt=6&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1145955048&clientId=20931. Read More