Modeling Human Learning as Context Dependent Knowledge Utility Optimization

Abstract. Humans have the ability to flexibly adjust their information process-ing strategy according to situational characteristics. However, such ability has been largely overlooked in computational modeling research in high-order hu-man cognition, particularly in learning. The present work introduces frameworks of cognitive models of human learning that take contextual factors into account. The framework assumes that human learning processes are not strictly error min-imization, but optimization of knowledge. A simulation study was conducted and showed that the present framework successfully replicated observed psychological phenomena.

Similarity metrics within a point of view

In vector space based approaches to natural language processing, similarity is commonly measured by taking the angle between two vectors representing words or documents in a semantic space. This is natural from a mathematical point of view, as the angle between unit vectors is, up to constant scaling, the only unitarily invariant metric on the unit sphere. However, similarity judgement tasks reveal that human subjects fail to produce data which satisfies the symmetry and triangle inequality requirements for a metric space. A possible conclusion, reached in particular by Tversky et al., is that some of the most basic assumptions of geometric models are unwarranted in the case of psychological similarity, a result which would impose strong limits on the validity and applicability vector space based (and hence also quantum inspired) approaches to the modelling of cognitive processes. This paper proposes a resolution to this fundamental criticism of of the applicability of vector space models of cognition. We argue that pairs of words imply a context which in turn induces a point of view, allowing a subject to estimate semantic similarity. Context is here introduced as a point of view vector (POVV) and the expected similarity is derived as a measure over the POVV's. Different pairs of words will invoke different contexts and different POVV's. Hence the triangle inequality ceases to be a valid constraint on the angles. We test the proposal on a few triples of words and outline further research

Is conscious processing required for long-term memory?

Models of memory (including those of the SAM-REM variety) are generally based on the assumption that storage of information in long-term memory is a function of the amount of elaborative processing given to the processed information. Here we explore the limits of such an assumption by examining the long-term effects of information that has only been processed at a subliminal level. We conclude that even subliminally presented information is stored to some extent and will lead to small but consistent effects in indirect memory tests but not on direct memory tests. To have an effect on a direct memory test, the information has to be clearly seen (as in the RSVP experiments discussed in this chapter) although here again, attentive processing does not appear to be required