Web Sitesi Kullanılabilirlik Ölçeğinin Geliştirilmesi: Geçerlik, Güvenirlik Analizi ve Uygulama Sonuçları

Yıl 2011, Cilt: 1 Sayı: 2 - Cilt: 1 Sayı: 2, 31 - 40, 15.07.2016

Ebru Kılıç Çakmak Erhan Güneş Mutlu Tahsin

Öz

Çalışmanın amacı, web sitelerinin kullanıcı algısına dayalı kullanılabilirlik düzeylerini belirlemeye yönelik bir “Web sitesi kullanılabilirlik ölçeği” geliştirmektir. Alanyazın taraması sonucunda kullanılabilirlikle ilgili boyutlar ortaya çıkarılmış ve bu bağlamda 53 soruluk madde havuzu oluşturulmuştur. Kapsam geçerliği için ölçek, 7 alan uzmanının görüşüne sunulmuştur. Uzman görüşleri doğrultusunda düzenlenen maddelerden oluşan taslak form, Gazi Üniversitesi Uzaktan Eğitim Meslek Yüksekokulu öğrenme yönetim sistemi web sitesini kullanan 245 öğrenciye uygulanmıştır. Kullanılabilirlik ölçeğinin yapı geçerliğini incelemek için Açımlayıcı ve Doğrulayıcı Faktör Analizi yöntemleri kullanılmış, güvenilirliklerinin belirlenmesi için de Cronbach alfa iç tutarlık katsayısı hesaplanmış, düzeltilmiş madde-toplam korelasyonu ve t testi kullanılarak üst %27 ile alt %27 grupların madde ortalamaları arasındaki farkların anlamlılığı incelenmiştir. Yapılan analizler sonucunda dört faktörlü yapıya sahip 25 maddeden oluşan kullanıcı algısına dayalı web sitesi kullanılabilirlik ölçeği elde edilmiştir. Son olarak, geliştirilen ölçek öğrenme yönetim sistemi web sitesinin kullanılabilirliğini belirlemek amacıyla 239 uzaktan eğitim öğrencisi üzerinde uygulanmış ve sonuçlar rapor edilmiştir.

Anahtar Kelimeler

Kullanılabilirlik, gezinme kolaylığı, tasarım, erişim kolaylığı, kullanım kolaylığı, ölçek geliştirme

Developing a Web Site Usability Scale: The Validity and Reliability Analysis & Implementation Results

Öz

The aim of this research was to develop a “User perception based web site usability scale” to be used for assigning usability of web sites based on user perception. After a literature review dimensions of usability were found out. Subsequently a pool of items including a total of 53 items was collected in this context. The draft form which was developed according to 7 subject matter experts’ opinions, was applied on 245 students who had been using Gazi University Distance Education Vocational College LMS (Learning Management System) web site. Exploratory and confirmatory factor analysis methods were used to determine construct validity. For reliability, Cronbach alpha internal consistency coefficient was taken into account; corrected item-total correlation and t-test were used to examine significance between item averages of top %27 and bottom %27 groups. As a result of the analysis process, the user perception based web site usability scale, with a construct of four factors including of 25 items, was developed. Finally, the scale was applied on 239 e-learners in order to determine the usability level of the LMS web site which they had been using and results were reported.

Anahtar Kelimeler

Usability, ease of navigation, design, ease of access, ease of use, scale development

Kaynakça

• Agarwal, R. & Venkatesh. V. (2002). Assessing a firm's Web presence: a heuristic evaluation procedure tor the measurement of usability. Information System Research. 13(2) . 168-186.
• Anderson, J. C. & Gerbing D.W. (1984). The effect of sampling error on convergence, improper solutions and goodness-of-fit indices for maximum likelihood confirmatory factor analysis. Psychometrika. 49(2). 155- 173.
• Asahi, T. & Miyai. H. (1990). “A Usability Testing Method Employing The ‘Trouble Model”. Human Factors and Ergonomics Society Annual Meeting Proceedings (s. 1233-1237). Human Factors and Ergonomics Society.
• Becker, A. (2007). Electronic commerce: concepts, methodologies, tools and applications. Hersley: Information Science Reference.
• Brinck, T., Gergle. D. & Wood. S. D. (2002). Designing Web sites that work: Usability for the Web. San Francisco: Morgan Kaufmann.
• Booth, P. (1989). An introduction to human-computer interaction. Lawrence Erlbaum Associates, Publishers. East Sussex.
• Büyüköztürk, Ş. (2005). Sosyal bilimler için veri analizi el kitabı (5. Baskı). Ankara: PegemAkademi.
• Clairmont, M., Dickstein, R., & Mills, V. (1998). “Testing of usability in the design of a new information gateway.” Paper presented at The Living The Future 2 Conference. University of Arizona.
• Claridge, N. & Kirakowski, J. (2005). WAMMI: Website Analysis and Measurement Inventory questionnaire. [Online] Retrieved on 15-October-2010. at URL: http://www.wammi.com/samples/index.html.
• Cole, D.A. (1987). Utility of confirmatory factor analysis in test validation research. Journal of Consulting and Clinical Psychology, 55. 1019-1031.
• Dix, A., Filay. J., Abowd, G. & Beale, R. (1998). Human- computer interaction (2nd Ed.). Upper Saddle River, NJ: Prentice Hall.
• Dumas, J. S. & Redish, J. C. (1993). A practical guide to usability testing. Norwood, N. J.: Ablex.
• Ebling, M. R. & John, B. E. (2000). On the contributions of different empirical data in usability testing. Proceedings of the conference on designing interactive systems: Processes, practices, methods, and techniques. 289-296. New York: Association for Computing Machinery.
• Furtado, E. & et. al. (2003). Improving usability of an online learning system by means of multimedia, collaboration, and adaptation resources. In Usability evaluation of online learning programs. ed. Claude Ghaoui. 69-86. Hershey. Pa.: Information Science Publication.
• Garson, G. D. (2009). “Quantitative research in public administration”. North Carolina State Üniversitesi College of Humanities and Social Sciences. [Online] Retrieved on 09-December-2010 at URL: http://www2.chass.ncsu.edu/garson/pa765/structur.htm
• Gluck, M. (1997). A descriptive study of the usability of geospatial metadata. Annual Review of OCLC Research.
• Guillemette, R. A. (1995). The evaluation of usability in interactive information systems. In Human factors in information systems: Emerging theoretical bases. ed. Jane M. Carey.Norwood. N. J.: Ablex.
• Gürses, E. (2005). Web Sitelerinde Kullanılabilirlik Çalışmaları ve Kullanılabilirlik Değerlendirme Yöntemleri. Akademik Bileşim 2005. Adana.
• Hix, D. & Hartson, H. R. (1993). Developing user interfaces: Ensuring usability through product and process. New York: John Wiley.
• International Standards Organization, (1994). Ergonomic requirements for office work terminals. Part 11: Guidance on usability (ISO DIS 9241- 11). with visual display
• International Standards Organization, Internet World Stats (2010). Usage and Population Statistic. [Online] Retrieved on 09-December-2010 at URL:http://www.internetworldstats.com.
• Jeffries, R. ve Desurvire, H. (1992). Usability testing versus heuristic evaluation: Was there a contest? SIGCHI Bulletin. 24(4). 39-41.
• Jeng, J. (2005). What is Usability in the Context of the Digital Library and How can it be measured? Information Technology and Libraries, 24 ( 2). 47-56.
• Jorgensen, A. H. (1990). Thinking-aloud in user interface design: A method promoting cognitive ergonomics. Ergonomics, 33(4). 501-507.
• Kassim, A., Rafee C. & T. R. Kochtanek (2003). "Designing. implementing & evaluating an educational digital library resource." Online Information Review, 27(3). 160-168.
• Kengeri, R. vd. (1999). Usability study of digital libraries: ACM, IEEE-CS, NCSTRL, NDLTD, International Journal on Digital Libraries 2. 157-69.
• Kim, K. (2002). A model of digital library information seeking process (DLISP model) as a frame for classifying usability problems. PhD diss., Rutgers Univ.
• Kirakowski, J. & Corbett, M. (1993). SUMI: The Software Usability Measurement Inventory. British Journal of Education Technology, 24(3). 210-212.
• Lewis, C. (1982). Using the "thinking-aloud" method in cognitive interface design. IBM Research Report RC 9265. Yorktown Heights. NY: IBM T. J. Watson Research Center.
• Lewis, J. R. (1990). Sample sizes for observational usability studies: Tables based on the binomial probability formula (Tech. Report 54.571). Boca Raton. FL: International Business Machines, Inc.
• Mars, H.W. & Hocevar. D. (1988). A new more powerful approach to multitrait-multimethod analyses: Application of second-order confirmatory factor analysis. Journal of Applied Psychology, 73(1). 107-117.
• Marsh, H.W., Balla, J. R. & McDonald, R. P. (1988). Goodness-of-fit indexes in confirmatory factor analysis: The effect of sample size. Psychological Bulletin, 103. 391-410.
• Monideepa, T. & Zhang, J. (2005). Analyzing the Influence of Web Site Design Parameters on Web Site Usability. Information Resources Management Journal, 18(4). 62- 80.
• Nielsen, J. (1993). Usability Engineering. Academic Pres, Boston.
• Nielsen, J. (2000). Designing web usability. New Riders Publishing. Indianapolis, IN.
• Oulanov, A. & E. J. Y. Pajarillo (2002). "CUNY+ Web: Usability study of the Web-based GUI version of the bibliographic database of the City University of New York (CUNY)." The Electronic Library 20(6): 481-487.
• Palmer, J. W. (2002). Web site usability, design, and performance metrics. Information Systems Research, 13(2). 151-167.
• Pearrow, M. (2000). Web Site Usability. Charles River Media. RockLand, MA.
• Rubin, J., Chisnell, D. (2008). How to Plan, Design, and Conduct Effective Test (2nd Ed.). Indianapolis. Indiana: Wiley Publishing, Inc.
• Shackel, B. (1986). Ergonomics in design for usability. In People & computers: Designing for usability. Proceedings of the second conference of the BCS HCI specialist group. ed. M. D. Harrison and A. F. Monk. Cambridge. England: Cambridge Univ. Pr.
• Shneiderman, B. (2004). Designing the User Interface: Strategies for Effective Human-Computer Interaction (4th Ed.). Addison-Wesley. Reading MA.
• Sümer, N. (2000). Yapısal eşitlik modelleri: temel kavramlar ve örnek uygulamalar. Türk Psikoloji Yazıları, 3 (6) 49- 74.
• Thomsett-Scott, B. C. (2006). Web site usability with remote users: Formal usability studies and focus groups. Journal of Library Administration, 45(3-4). 517-547.