Applying Analogical Reasoning Techniques for Teaching XML Document Querying Skills in Database Classes
2012; Volume: 23; Issue: 4 Linguagem: Inglês
ISSN
2186-3679
Autores Tópico(s)Semantic Web and Ontologies
Resumo1. XML QUERY SKILLS IN THE IS CURRICULUM The IS2010 model curriculum (Topi et al 2010) does not include any mention of XML, although IS2010 does include extensive coverage of database skills. Students who graduate from a typical IS program will have sufficient understanding of relational technologies and SQL for querying databases, but often lack training in XML structures or the use of XPath/XQuery for querying XML documents. XML's hierarchical data structure is more suitable than the tabular structure of relational databases for some data storage and representation purposes. Partly for this reason, XML has become ubiquitous, especially as a means of exchanging information between applications over the internet. In addition, more and more database management systems incorporate XML data types and querying functionality into their engines. For example, major database products like Oracle and Microsoft's SQL Server have incorporated data structures and associated functionality for storing and processing XML-formatted data. There also appears to be an increasing coverage of XML in database textbooks. For example, in Hoffer et al 7th edition of Modern Database Management, only two full pages (422-424) are devoted to XML coverage, and there is no tight integration of this topic with the topic of Web Services. By contrast, the 11th edition devotes 10 pages (360-369) and makes a stronger connection to Web Services. It makes sense that XML coverage should get greater attention in an IS curriculum, since it has become so prevalent in the real world. Consequently, there have been some advances in XML pedagogy as described in the IT education literature. For example, Olsen et al (2005) discuss integrating XML into database courses, and present a sample database for a medical clinic in SQL Server and queries that make use of SQL Server's XML processing to perform queries on the database and produce results in XML format. Wagner et al. (2008) outline a set of considerations for incorporating XML into the MIS curriculum, including contrasting XML with HTML, structuring XML coverage using a system model framework, covering the plethora of XML-related technologies, and discussing the meta-language nature of XML. Specific courses that could benefit from XML coverage include database, systems analysis and design, ecommerce, and web development. A complete coverage of all aspects related to XML including style sheeting, metadata declarations (DTDs and XML Schemas), XML extension frameworks (e.g. XBRL, RSS, SOAP, RDF), and other advanced topics could merit an entire course in itself. But, for the purposes of providing data query and analysis skills relevant for a database or BI course, a much smaller subset of XML-related topics would suffice. In particular, if a database course can provide a thorough understanding of the structure of XML documents(hierarchical, tree-like), along with practical experience with the associated query languages of XPath (XML Path Language) and XQuery, then this would go a long way toward enhancing students' facility with XML in general. The problem is time. With an already full schedule of topics to cover, database classes are hard-pressed to incorporate new content. 2. ANALOGICAL REASONING AND PEDAGOGY The prospect of incorporating significant XML querying skills into an already busy database course schedule can be daunting. How can we include these skills without overloading the curriculum? The challenge is to create an avenue for providing deep understanding in a minimal amount of time. In order to do this, we can make use of analogical pedagogy (James 2003, Harrison 1993, Clement 1993), which capitalizes on the promise that students can quickly learn basics by making analogies between a new skill to be learned and an already well-established skill. In our case, the challenge is to bootstrap on the already existing skill of database students for using SQL SELECT statements to query relational databases in order to produce equivalent skills for querying XML documents in a time-efficient fashion. …
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