طراحان وب و کاربران وب: تاثیر کیفی ارگونومیک وب سایت بر جستجوی اطلاعات

Despite rapid growth in the number of web sites, there is still a significant number of ergonomic problems which hinder web users. Many studies focus on analysing cognitive processes and difficulties experienced by web users, but very few are interested in web designers’ difficulties or in comparing their respective activities. Towards this end, the two experimental studies presented in this article compare the strategies developed both by professional web designers and (novice vs. experienced) web users while searching for information on web sites of varying ergonomic quality. More precisely, we investigated whether web designers can effectively use their own strategies as web users when designing web sites. We presented a comparison of novice web users, experienced web users and professional web designers searching behavior and cognitive load when using ergonomic and non-ergonomic web sites. In addition, we asked web designers to predict the strategy used by novice web users. Based on the results obtained in the two experiments, we conclude that web designers are not able to predict strategies of novice users and do not behave like novice users. Consequently, ways for supporting web designers in developing a user-centered activity are necessary, and certain ways are suggested at the end of this article.

Koenemann and Belkin (1996) have signaled a dramatic increase in the number of information sources that have become available to an exponentially growing number of users with very little training in searching for information in such systems. Pirolli and Card (1999) have underlined the fact that the quantity of web pages doubles every year. In more recent years, this trend has continued to increase, and e-commerce sites are contributing to in this rapid growth (Forrester, 2002; Richard and Chandra, 2005; Wang and Emurian, 2005). The facility with which a large public can be reached in a short time partially explains this interest in web sites. Nevertheless, they are still considered as difficult to use and to access (Lee, 1999; Mc Crickard, 2001; Teo et al., 2003; Bhatt, 2004; Ling and van Schaik, 2006; Stronge et al., in press). Given this rapid growth in number, web sites are constantly in competition. Consequently, they have to be precise, concise and rapid, since web users, having more choice than ever, will not waste time on web sites which are confusing, too slow and not well adapted to users’ needs (Helander and Khalid, 2000; Wang and Emurian, 2005). Therefore, the implementation of an organized and intuitive navigational system is critical to user success, especially in web navigation, because users see individual sites as subsets within their overall Internet experience, and users frequently are unaware they have left a specific site (Spool et al., 1999; Nielsen, 2000; McEneaney, 2001). In order to determine precisely the problems and cognitive difficulties that web users experience, more and more researchers study the cognitive processes involved and difficulties experienced by users when navigating the Web (see, e.g. Rouet and Tricot, 1998; Navarro-Prieto et al., 1999; Pearson and van Schaik, 2003; Rouet, 2003; Pratt et al., 2004). Findings about users’ cognitive functioning have ergonomic implications for designers (see, e.g., Hong et al., 2004; Oulasvirta, 2004) and for the creation of guidelines and checklists (see, e.g., Bastien et al., 1999; Spool et al., 1999; van Duyne et al., 2002; Ozok and Salvendy, 2004). Nevertheless, we also assert that understanding designers’ activities and identifying the difficulties that designers experience are essential to improving the ergonomic quality of web sites. More precisely, research on users’ and designers’ cognitive activities must be conducted jointly to help designers concretely and efficiently consider future users’ needs when designing web sites. In this paper, we assert that determining differences between designers and users while navigating will clarify the reasons why designers cannot sufficiently take into account users’ needs when creating web sites. The question of designers’ and users’ differences have been largely ignored, except one recent article by Park et al. (2004) has examined users’ esthetical preferences. In order to address the research needs in this area, we present in this article two experiments conducted with novice web users, experienced web users and professional web designers involved in information search tasks. These experiments aim to compare the search strategies and cognitive resources that (novice vs. experienced) users and professional designers employ while searching for information according to the ergonomic quality of the site (a site with ergonomic problems vs. a site incorporating ergonomic recommendations). The following section provides an overview of information search activity and cognitive load. 3 and 4 present the two experimental studies. The results obtained are discussed in Section 5. Suggestions to help web designers’ activities are presented in Section 6.

We discuss the results of the two experiments on both the role of the level of experience (Section 5.1) and the ergonomic quality of the site (Section 5.2). 5.1. The role of the level of experience Results of these two experiments showed that the experienced users and professional designers developed closely related search activities (except for some results such as the time required to find information or the answers to the grades obtained in the questionnaire on usability satisfaction), whereas professional designers and novice users developed two different and unrelated search activities. In the two experiments, search times for novice users were longer than for experienced users, regardless of the ergonomic quality of the site. These results were corroborated by the fact that novice users visited more hyperlinks, opened up more web pages and more often read web pages linearly than experienced users and professional designers. Moreover, novice users recalled fewer elements seen on visited web pages and more irrelevant ones than experienced users and professional designers. These results reflect understanding difficulties for novice users of the search task to be performed: they spent more time developing and using cognitive processes adapted to their information search activities, as shown by Hölscher and Strube (2000) and Sweller (1998, 1999). In addition, novice users, while navigating the non-ergonomic site, recalled more irrelevant elements than relevant elements. Novice users’ activities were guided by the structure and elements on the web pages, and so they were more affected by the ill-structured web site than experienced users (and designers), as shown by Hofman and van Oostendord (1999), and Potelle and Rouet (2003). Consequently, novice users experienced difficulties building up a global organization of the web site (i.e. a coherent mental model) and chunking elements, unlike experienced users and professional designers. Furthermore, and contrary to our hypothesis, professional designers did not spend significantly less time than novice users finding correct answers (in the two experiments). However, designers visited fewer hyperlinks than the other participants. On the non-ergonomic site, designers looked for a possible navigational framework at the top of the page, whereas novice users spent little time looking for it. Therefore, professional designers automatically applied procedures acquired with experience (looking for a menu that usually supports their navigation activities in web sites), while novice users had not yet acquired this knowledge. In addition, professional designers scanned the web pages more often than novice users, while novice users read the web pages linearly more often than professional designers. Thus, designers and novice users did not use the web site in the same way, although their search times were not significantly different (in the two experiments). Indeed, novice users, because of their lack of understanding, rapidly compromised themselves by opening hyperlinks and visiting new web pages, whereas all of the professional designers opened web pages before clicking on a new hyperlink. Results from the usability satisfaction questionnaire (experiment 1) show that the professional designers were aware of the difficulties generated by the non-ergonomic site, but that they experienced difficulties anticipating the users’ navigation activities: the designers thought that the novice users would choose the correct hyperlink by trial and error. In reality, only two out of the ten novice users adopted this strategy while navigating the non-ergonomic site. Once the accurate hyperlink was selected by novice users on the web page, designers indicated that the novice users would follow the same path as the designers. In these experiments, we noticed that this was not the case, since the novice users recorded more steps than the designers and read linearly more often than the designers. These results reflect the fact that designers actually experienced difficulties detaching themselves from their own viewpoints to consider the user's viewpoint, in part because they have developed automatic procedures in searching for information. They thought that the novice users would adopt the same behavior or strategy as them. This corresponds to what van Duyne et al. (2002) call the ‘ego bias’, i.e. designers believe that all individuals use web sites like them. 5.2. The effect of the ergonomic quality of the web site On the non-ergonomic site, many irrelevant elements were introduced (advertising banners, flashing items, etc.). According to Sweller, 1988 and Sweller, 1999, irrelevant elements distract users and, for the less experienced, may overload working memories. In our two studies, the novice users experienced difficulties ignoring and inhibiting irrelevant elements presented in the non-ergonomic site, since they recalled more irrelevant elements that relevant ones, and novices recalled fewer relevant elements than experienced users and professional designers. This generated difficulties in planning their future actions, anticipating their activities and so selecting relevant elements to answer questions. Thus, novice web users experienced difficulties in developing evaluation activity, which consists in determining whether available information is relevant to the objective (goal representation maintained in working memory—see Rouet and Tricot, 1996 and Rouet and Tricot, 1998). These results also corroborate previous findings which showed that distracting elements slowed down the information search, and that certain visual characteristics, such as colors, shapes, size, structure of web pages, guided users’ attention (Anderson et al., 1998; Wickens and Hollands, 2000; Hong et al., 2004). This can explain the increase in the search time, the number of visited hyperlinks for novice users and the few recalled elements (with a significant proportion of irrelevant ones). Another very interesting result appeared. Contrary to our hypothesis, the ergonomic site required significantly more cognitive resources for the users than the non-ergonomic site. These results, not in accordance with Sweller, 1988 and Sweller, 1999 in which a non-adapted presentation of information leads to a higher extraneous cognitive load, can be explained by different ways of managing of cognitive resources: resource commitment leads to the protection of cognitive resources, i.e. through reducing cognitive load, whereas task commitment leads to the monopolization of resources involved in the task (see Cegarra and Hoc, 2006). Indeed, users visiting the ergonomic site could dedicate more cognitive resources to their information search activities than users visiting the non-ergonomic site, since the users of the ergonomic site were not distracted by irrelevant elements which could disturb their attention. They could focus their attention on the task to be performed. We can also explain these results by the fact that users navigating the non-ergonomic site did not try to assimilate all of the elements presented on the web pages (they recalled fewer elements on the non-ergonomic site than on the ergonomic site), contrary to learning systems used by Sweller, so their working memory were not overloaded. Therefore, the cognitive theory of Sweller should be adapted to information search by decreasing the importance allocated to the process and the understanding of all of elements present in the site, at least when experience in navigation increases. Professional designers navigating the non-ergonomic site did not use significantly more cognitive resources than designers navigating the ergonomic site. Using the non-ergonomic site, professional designers looked for the navigational framework (missing on the web pages), while very few novice users looked for it. Professional designers scanned pages more often than novices, whereas novices linearly read the web pages more often than designers, and professional designers recalled more page titles than novice users. Consequently, designers’ schemata got activated almost automatically while navigating the web sites, and added extraneous load did not disturb their activities. Their level of experience allowed them to overcome ergonomic problems, to deal with them without requiring many cognitive resources, and thus the construction of a coherent mental model of the visited web site.