Adam Carlson

Text forum features for small group discussions with facet-based pedagogy

We describe an approach to teaching that engages students in small-group discussions of conceptual material. Then we describe software that mediates the discussions with an online textual newsgroup-like system that has special features to support a pedagogical approach that deals explicitly with student preconceptions. Our system, called INFACT-FORUM, is part of a larger CSCL system called INFACT that supports student discussion, computer-assisted assessment, display of student progress data, and support for pedagogical intervention.

Learning to identify student preconceptions from text

Automatic classification of short textual answers by students to questions about topics in physics, computing, etc., is an attractive approach to diagnostic assessment of learning. We present a language for expressing rules that can classify text based on the presence and relative positions of words, lists of synonyms and other abstractions of a single word. We also describe a system, based on Mitchells version spaces algorithm, that learns rules in this language. These rules can be used to categorize student responses to short-answer questions. The system is trained on written responses captured by an online assessment system that poses multiple choice questions and asks the student to justify their answers with textual explanations of their reasoning. Several experiments are described that examine the effects of the use of negative data and tagging students explanations with their answer to the original multiple choice question.

Using Graphical Models to Unobtrusively Assess Student Performance in Educational Image Processing Activities

Unobtrusive educational assessment is a means of measuring student progress using the byproducts of authentic learning activities. It is difficult to perform well. Using a new technology based on graphical models, unobtrusive assessment can become more practical. We describe how we apply our techniques in teaching image processing to undergraduates. Our methods for unobtrusive assessment are applicable when learning activities are computer-based and involve the manipulation of tools such as construction kits, simulations, and programming languages.

Sequential Input Graphical Model Assessment Diagrams for Analysis of Student Activity Data

A formalism called sequential Input graphical model assessment (SIGMA) diagrams is introduced. It shares with conventional graphical models features for specifying probabilistic inferences. In addition, it provides facilities for describing temporal patterns of evidence. The formalism was motivated by a need for transparent representations of assessment processes in the INFACT online learning environment. An editor and interpreter for SIGMA diagrams have been implemented and embedded in INFACT. The interpreter works with either stored event data, real-time event processing, or a combination of both. Examples diagrams are given, and the expressive power of the formalism is discussed.