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skhemlani (45)

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NOV
2014
19

Theory on unique probabilities out in Cognitive Science

Max Lotstein, Phil Johnson-Laird and I published a paper in Cognitive Science on how people estimate unique probabilities, like the probability that Jeb Bush will be elected US President in 2016. The theory hinges on how mental models of beliefs are used to update iconic representations of probability. Here’s a link and here’s the abstract:

We describe a dual-process theory of how individuals estimate the probabilities of unique events, such as Hillary Clinton becoming U.S. President. It postulates that uncertainty is a guide to improbability. In its computer implementation, an intuitive system 1 simulates evidence in mental models and forms analog non-numerical representations of the magnitude of degrees of belief. This system has minimal computational power and combines evidence using a small repertoire of primitive operations. It resolves the uncertainty of divergent evidence for single events, for conjunctions of events, and for inclusive disjunctions of events, by taking a primitive average of non-numerical probabilities. It computes conditional probabilities in a tractable way, treating the given event as evidence that may be relevant to the probability of the dependent event. A deliberative system 2 maps the resulting representations into numerical probabilities. With access to working memory, it carries out arithmetical operations in combining numerical estimates. Experiments corroborated the theory’s predictions. Participants concurred in estimates of real possibilities. They violated the complete joint probability distribution in the predicted ways, when they made estimates about conjunctions: P(A), P(B), P(A and B), disjunctions: P(A), P(B), P(A or B or both), and conditional probabilities P(A), P(B), P(B|A). They were faster to estimate the probabilities of compound propositions when they had already estimated the probabilities of each of their components. We discuss the implications of these results for theories of probabilistic reasoning.

JUL
2014
12

LRW 8 presentation on conditional probabilities

I recently gave a talk on the conditional probabilities of unique events (Khemlani, Lotstein, & Johnson-Laird, 2014) at the 8th London Reasoning Workshop at Birkbeck College. You can download the presentation here.
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APR
2014
22

Monsters for science

Earlier this year, Abby Sussman, Danny Oppenheimer and I published a paper on latent scope biases in higher cognition. One of the fun things about writing the paper is that to prepare the materials for the experiment, we worked with Mike Lariccia, a friend who’s also a fantastic illustrator of graphic novels.
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DEC
2013
20

Paper on kinematic mental simulations out in PNAS

I recently published a paper on kinematic mental simulations in PNAS. The paper is with Monica Bucciarelli, Robert Mackiewicz, and Phil Johnson-Laird, and it examines how reasoners without any background in computer science or logic can construct mental “algorithms” in a systematic way, akin to recipes or driving directions.
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JUL
2013
13

Summer presentation schedule

I’ll be giving presentations at various conferences over the summer, so I’ve provided my schedule below. Stop by if you’re around!
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