Josje Lodder

Open Universiteit Nederland | OU · School of Computer Science

This paper describes logax , an interactive tutoring tool that gives hints and feedback to a student who stepwise constructs a Hilbert-style axiomatic proof in propositional logic. logax generates proofs to calculate hints and feedback. We compare these generated proofs with expert proofs and student solutions, and conclude that the quality of the...

Structural induction is a proof technique that is widely used to prove statements about discrete structures. Students find it hard to construct inductive proofs, and when learning to construct such proofs, receiving feedback is important. In this paper we discuss the design of a tutoring system, LogInd, that helps students with constructing stepwis...

This article describes an experiment with LogEx, an e‐learning environment that supports students in learning how to prove the equivalence between two logical formulae, using standard equivalences such as DeMorgan. In the experiment, we compare two groups of students. The first group uses the complete learning environment, including hints, next ste...

This paper describes an algorithm to generate Hilbert-style axiomatic proofs. Based on this algorithm we develop logax, a new interactive tutoring tool that provides hints and feedback to a student who stepwise constructs an axiomatic proof. We compare the generated proofs with expert and student solutions, and conclude that the quality of the gene...

An important topic in courses in propositional logic is rewriting propositional formulae with standard equivalences. This paper analyses what kind of feedback is offered by the various learning environments for rewriting propositional logic formulae, and discusses how we can provide these kinds of feedback in a learning environment. To give feedbac...

LogEx is a learning environment that supports students in rewriting propositional logical formulae, using standard equivalences. We organized a pilot study to prepare a large scale evaluation of the learning environment. In this paper we describe this study, together with the outcomes, which teach us valuable lessons for the large scale evaluation.

In this paper we describe a teaching tool for proving equivalences between propositional logic formulae, using rewrite rules such as De Morgan’s laws and double negation. This tool is based on an earlier tool for rewriting logical formulae into disjunctive normal form (DNF). Both tools make use of a rewrite strategy, which specifies how an exercise...

At the Open University we are developing tools to support students in learning procedural skills. The tool for rewriting logical formulas into disjunctive normal form was tested with students in the period 2007-2008. The results of this tests help us to improve our tool, give answers to some questions we had during the development and encourage us...