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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 probabi-listic theory, i.e., the Item(More)
—Adaptive testing systems generate tests for assessment that are tailored to each student. In these tests, students are assessed through a process that uses Item Response Theory (IRT), a well-founded psychometric theory. This theory is responsible for estimating student knowledge, determining the next question that must be posed at each moment, and deciding(More)
Most of the information of the WWW is not adaptive, rather it is dispersed and disorganized. Another difficulty is to find tools that help to create adaptive courses. SIGUE is an author tool that makes it possible to build adaptive courses using web pages that already exist. This means that if there is a lot of information on the web about the same topic(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)
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)
Multilayers of sodium salt of poly(4-styrene sulfonate) (PSS) and poly(diallyl dimethyl ammonium) chloride (PDADMAC) have been built layer by layer (LbL) both at the solid/aqueous interface (solid supported) and the air/aqueous interface (liquid supported). For the solid-supported multilayers, the adsorption kinetics and the complex shear modulus were(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)