Measuring Web Application Quality with WebQEM

using WebQEM, a quantitative evaluation strategy to assess Web site and application quality. Defining and measuring quality indicators can help stakeholders understand and improve Web products. An e-commerce case study illustrates the methodology's utility in systematically assessing attributes that influence product quality. T he Web plays a central role in such diverse application domains as business , education, industry, and entertainment. Its growing importance heightens concerns about Web application development methods and argues for systematic, disciplined use of engineering methods and tools. 1 In particular, we need sound evaluation methods for obtaining reliable information about product quality. These methods should identify attributes and characteristics that can serve as meaningful indicators for specific evaluation goals given a user viewpoint. This article discusses the Web Quality Evaluation Method 2 and some aspects of its supporting tool, WebQEM_Tool. 3 Using WebQEM to assess Web sites and applications supports efforts to meet quality requirements in new Web development projects and evaluate requirements in operational phases. It also helps us discover absent features or poorly implemented requirements such as interface-related design and implementation drawbacks or problems with navigation, accessibility, search mechanisms, content, reliability, and performance. We follow common practice in describing software quality in terms of quality characteristics as defined in the ISO/IEC 9126-1 standard. 4 The literature often characterizes quality, cost, or productivity requirements as nonfunctional, and measuring these less tangible characteristics directly isn't practical, but we can assess them by measuring the product's " lower abstraction attributes. " 5 We see attributes as measurable properties of an entity—here, a Web application—and propose using a quality model (in the form of a quality requirement tree) to specify them. In this context, stakeholders must focus on characteristics and attributes that influence product quality and " quality in use. " 4 (Ensuring high product quality doesn't always suffice to guarantee quality in use, but such discussion exceeds this article's scope.) Specifically, characteristics that influence product quality as prescribed in the ISO 9126-1 standard include usability, func-tionality, reliability, efficiency, portability, and maintainability. To specify the quality requirement tree for a given assessment goal and user viewpoint, we should consider such diverse attributes as broken links, orphan pages, quick access pages, table of contents, site map, link color uniformity, and main control permanence. Of course, we recognize how difficult it is to design a rigorous nonfunctional requirement model that provides a strong correlation between attributes and characteristics. Though …