215 8 4 -    $’  Eleni Michailidou, Simon Harper and Sean Bechhofer Information Management Group School of Computer Science The University of Manchester Manchester, M13 9PL, UK michailidou@cs.manchester.ac.uk {simon.harper, sean.bechhofer}@manchester.ac.uk + The visual appearance of a Web page influences the way a user will interact with the page. Web page structural elements (such as text, tables, links, and images) and their characteristics (such as colour and size) are used to determine the visual presentation and complexity level of a Web page. We theorise that by understanding a user’s visual and aesthetic perception of a Web page we can understand the cognitive effort required for interaction with that page. This paper describes an investigation into user perception of the visual complexity and aesthetic appearance of Web pages. Results show a strong and high correlation between users’ perception of visual complexity, structural elements (links, images, words and sections) and aesthetic appearance (organisation, clearness, cleanliness, interestingness and beautifulness) of a Web page. We argue that the results should be used as a further understanding for keeping the balance between aesthetic appearance of a Web page and its visual complexity. Web pages will then be designed that can still be aesthetically attractive but also usable and not overloaded with information for the users. !  7  H.5.2 [" ]: Evaluation/Methodology, Screen Design; H.5.4 [’(8’]: User issues; I.7.2 [! !]: Document Preparation, Hypertext/Hypermedia 0  Design, Experimentation, Human Factors. 5’% Web Design, Visual Perception, Aesthetics, Visual Complexity, ViCRAM. 9.+" Web page designers focus on good visual presentation to im/ plicitly help users navigate, understand, and interact with the content. Access to, and movement around, complex hypermedia environments, of which the Web is the most popular example, has long been considered an important and major issue in the Web design and usability field [7, 9]. With the rapid and constant advancement of technology, new ways are constantly being introduced to present information that leads to visually complex Web pages. Studies [14, 8] show that distinct layout, smart captions and interesting pictures can transform a wall of dry text into a presentation which users will approach enthusiastically. The information on most of these Web pages is visually fragmented and organized into groups [2]. In this way, when sighted users reach a Web page, they can scan the page and obtain a comprehension of it in an average of 5 seconds. By that time they have decided if the page is relevant to their task and have moved towards the part of the page that interests them. Human/computer interaction research is mostly emphasized on performance criteria, such as time to learn, error rate and time to complete a task [6] and pays less attention to aesthetics. Lately, researchers have tried to understand how visual aesthetics can affect viewer’s perception [13, 15, 28, 18] but the relationship between the aesthetic presentation of a Web page and the user’s interaction needs further exploration. Our previous work investigated the relationship between user’s perception and visual complexity of a Web page [20]. It was shown that visual complexity of Web pages depends on the presentation of the page’s elements and by the density and diversity of the elements that are presented. Diversity is defined as the variety of structural elements and density as the number of each structural element on the page. A framework was developed that defines the visual complexity level of a page (simple, medium, complex) using a set of structural elements (number of images, links, words, and forms). In this paper, we present an evaluation that examines how users relate aesthetic appearance of a Web page with its visual complexity. The study revealed a strong relation between visual complexity, aesthetics and layout of a Web page. Results also validated our previous work which give a more robust basis for our assumptions. Conclusions are drawn about user perception and cognition in relation with the visual presentation and structure of Web pages. We assert that this information can be used by Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. SIGDOC’08, September 22–24, 2008, Lisbon, Portugal. Copyright 2008 ACM 9781605580838/08/0009...$5.00.