A proposal to improve the Simple Query Interface (SQI) of Learning Objects repositories Salvador Otón, José R. Hilera, Eva García, Antonio García, Luis de-Marcos, Antonio Ortíz, José A. Gutiérrez, José J. Martínez, José M. Gutiérrez, Roberto Barchino Computer Science Department University of Alcalá Alcalá de Henares, Madrid, Spain salvador.oton@uah.es Abstract—This paper proposes to improve the Simple Query Interface (SQI), designed to query learning object repositories, modifying a few existing methods to generate new ones. Replacement is not intended, instead, our proposal is to create new methods that incorporate several enhancements in order to enable compatibility with currently compliant systems that use the old methods. Besides, new methods are also proposed aiming at improving the interface as well as at providing compatibility with the Simple Publishing Querying (SPI) specification. With these improvements SQI specification will perform its task in a more structured and efficient manner. Keywords-SQI SPI, interface, e-learning, repositories I. INTRODUCTION Simple Query Interface (SQI) was published by the European Committee for Standarization in 2005. Its objective is to facilitate interoperability between public learning object repositories and the applications that use them [1, 2]. SQI interface comprises the set of methods provided by a repository, in such a way that remote clients may query over the learning objects stored in such a repository. These methods enable to perform different operations, but it is possible to improve a few of them. Specifically, a modification of the methods synchronousQuery and asynchronousQuery is proposed without removing them, so that compatibility with older systems is kept. Besides, we propose to add two new methods, namely downloadResource and asynchronousDownloadResource, that enable direct download of learning objects synchronously or asynchronously. The state of the art and some comparative evaluation results are presented in [3]. Section II presents an introduction to SQI interface core concepts. Section III introduces the first proposal for upgrading (modification existing methods). Section IV presents the second proposed improvement (addition of the downloadResource method along with its asynchronous counterpart). Finally Section V provides conclusions. II. SIMPLE QUERY INTERFACE A. SQI methods SQI specification comprises thirteen methods divided into three groups: configuration methods, session management methods and query methods. Query methods can be further divided into synchronous query methods and asynchronous query methods. Table I presents new SQI methods proposed to improve the specification. TABLE I. CLASSIFICATION OF SQI METHODS, INCLUDING THE NEW METHODS PROPOSED QUERY METHODS SYNCHRONOUS QUERY ASYNCHRONOUS QUERY synchronousQueryObject (sessionID, queryStatement, startResult): queryResults asynchronousQueryObject (sessionID, queryStatement, queryID) queryResultsListenerObject (queryID, queryResults) downloadResource (sessionID, resourceID, downloadType): byte[] asynchronousDownloadResource (sessionID, queryStatement, queryID) downloadResourceResultsListener (queryID, queryResults) B. SQI fault codes SQI interface also describes seventeen fault codes that current methods may throw. Three new fault codes have been incorporated because they are used by the new methods. Table II presents new fault codes. TABLE II. NEW SQI FAULT CODES PROPOSED CODE DESCRIPTION SQI-00017 Invalid resource identifier SQI-00018 Download IO error SQI-00019 Download mode not supported It worth mentioning that fault code SQI-00017 corresponds to fault code SPI-00005 of the SPI specification. SPI is used to publish contents in repositories [4]. So our 2010 10th IEEE International Conference on Advanced Learning Technologies 978-0-7695-4055-9/10 $26.00 © 2010 IEEE DOI 10.1109/ICALT.2010.25 64