Eduardo Guzmán

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Student assessment is a very important issue in educational settings. The goal of this work is to develop a web-based tool to assist teachers and instructors in the assessment process. Our system is called SIETTE, and its theoretical bases are Computer Adaptive Testing and Item Response Theory. With SIETTE, teachers worldwide can define their tests, and(More)
This paper presents an approach to student modeling in which knowledge is represented by means of probability distributions associated to a tree of concepts. A diagnosis procedure which uses adaptive testing is part of this approach. Adaptive tests provide well-founded and accurate diagnosis thanks to the underlying probabilistic theory, i.e., the Item(More)
Neural retina leucine zipper (NRL) is an essential transcription factor for cell fate specification and functional maintenance of rod photoreceptors in the mammalian retina. In the Nrl(-/-) mouse retina, photoreceptor precursors fail to produce rods and generate functional cone photoreceptors that predominantly express S-opsin. Previous global expression(More)
Testing is the most generic and perhaps most widely used mechanism for student assessment. Most tests are based on the classical test theory, which says that a student's score is the sum of the scores obtained in all questions plus some kind of error. The most relevant is that the student test result depends heavily on the individual's learning preferences(More)
This work presents a model for student knowledge diagnosis that can be used in ITSs for student model update. The diagnosis is accomplished through Computerized Adaptive Testing (CAT). CATs are assessment tools with theoretical background. They use an underlying psychometric theory, the Item Response Theory (IRT), for question selection, student knowledge(More)
PURPOSE During retinal development, post-mitotic neural progenitor cells must activate thousands of genes to complete synaptogenesis and terminal maturation. While many of these genes are known, others remain beyond the sensitivity of expression microarray analysis. Some of these elusive gene activation events can be detected by mapping changes in RNA(More)
In this paper, we present a blended e-learning experience consisting of supplying an undergraduate student population (in addition to traditional on-site classes) with a learning tool called OOPS (Object Oriented Programming System) and a testing system called SIETTE. OOPS is a problem-solving environment in which students can resolve Object Oriented(More)
SIETTE is a web-based adaptive testing system. It implements Computerized Adaptive Tests. These tests are tailor-made, theory-based tests, where questions shown to students, finalization of the test, and student knowledge estimation is accomplished adaptively. To construct these tests, SIETTE has an authoring environment comprising a suite of tools that(More)