Modeling individual differences in response time and accuracy in numeracy.

Area of Science:

• Cognitive Psychology
• Mathematical Cognition
• Decision Science

Background:

• Numeracy research often uses response time (RT) or accuracy, leading to debates on their correlation and relation to individual differences.
• Previous studies show inconsistent findings regarding correlations between RT, accuracy, and cognitive abilities like IQ and math skills.

Purpose of the Study:

• To integrate response time (RT) and accuracy as dependent variables in numeracy research.
• To apply a diffusion decision-making model to understand the relationship between numeracy skills and decision-making parameters.
• To reconcile contradictory findings in numeracy research by providing a theoretical framework.

Main Methods:

• Collected data from four numeracy tasks: numerosity discrimination, number discrimination, and memory for two- and three-digit numbers.
• Applied the diffusion decision-making model (Ratcliff, 1978) to analyze accuracy and RT data.
• Manipulated decision criteria by instructing participants to prioritize speed or accuracy.

Main Results:

• Accuracy and RTs correlated across tasks, but not negatively with each other.
• The diffusion model revealed significant correlations between numeracy information quality (drift rate) and speed-accuracy criteria across tasks.
• Individual differences in decision criteria persisted even when participants were instructed to prioritize speed or accuracy.

Conclusions:

• A decision-making model provides a theoretical basis for understanding numeracy task performance, integrating RT and accuracy.
• Consistent numeracy skills and decision criteria across tasks suggest underlying shared mechanisms.
• Individual decision-making criteria appear to be stable traits that can be modulated but not entirely overridden.