My research investigates how children and adults understand uncertainty when it is communicated verbally, especially by verbal probabilities, and therefore how they make decision on this basis. More specifically I investigate if and how children take into account all dimensions of verbal probabilities when judging and deciding. Indeed the specificity of such expressions is that they not only communicate a degree of possibility that an event occurs (i.e. a numerical value); they also focus the attention of the listener on the outcome or on its absence because of its linguistic dimension (i.e. the directionality). A second interest of mine is therefore the cognitive and linguistic determinants of the weight of those different dimensions.

As part of my M.Rs I realized a first study with Gaëlle Villejoubert (CLLE-LTC, University of Toulouse, France), comparing 8 year-olds’ (French third grade) and young adults’ (undergraduates) utilization of verbal probabilities in a game situation. This work indicates that children are able to take into account the level of uncertainty to make decisions but don’t judge it as accurately as adults do (see Gourdon & Villejoubert, 2009).

These findings were partially replicated with English-speaking children: when judging the level of uncertainty according to verbal probabilities, children use only the directionality. However use of both dimensions in decision-making could not be replicated (see Gourdon & Beck, 2009, for possible methodological explanations).

While working towards improving the children task, I am also currently trying to understand why the directionality might be the first dimension taken into account developmentally. Hence I am running adult studies aiming to determine if intrinsic differences between both dimensions (directionality and numerical value) can explain an easier access to directionality.

I am also expecting to address the link between individual differences (especially regarding the cognitive style) and the importance given to the directionality. First results in this direction were unfruitful, potentially to insufficient variance in cognitive style within our population.

Gourdon, A. & Beck, S. R. (2009). Children's judgements and decisions under verbal uncertainty. Poster presented at the 22nd Subjective Probability, Utility and Decision Making Conference, Rovereto, Italy, 23-27 August.

Gourdon, A., & Villejoubert, G. (2009). A comparison of children and adults' judgements and decisions based on verbal uncertainty statements. In N.A. Taatgen & H. van Rijn (Eds.), Proceedings of the 31st Annual Conference of the Cognitive Science Society. Austin, TX: Cognitive Science Society.