Uncertainty guides learning: How children learn and revise new word meanings in ambiguity

When children learn novel words, referential ambiguity is a constant challenge. However, despite facing this uncertainty, children acquire their vocabulary with remarkable ease. One possible key to their success might be that children use active learning strategies and employ their developing metacognitive skills. To test this idea, we assessed whether 4- to 5-year-old preschoolers (and adults) are aware of their own uncertainty during referent identification, and to what extent they can effectively use this information to guide their learning process. Participants encountered a series of labeling events that varied in referential ambiguity: from minimal (e.g., hearing a familiar label), to medium (hearing a novel label in presence of a familiar and a novel object, resolvable via mutual exclusivity), to maximal (hearing a novel label in presence of two novel objects). Following this, they received counterevidence to their initial word-object-mappings and decided which mappings (learned in more vs. less ambiguous contexts) to update. Results revealed three key findings: First, both children’s and adults’ explicit and implicit uncertainty increased with the amount of referential ambiguity. Second, when confronted with uncertainty, children spontaneously aimed to resolve this by seeking additional information. Third, while adults preferentially updated words learned in higher ambiguity, children instead tended to revise information that was learned less recently, leaving open questions about whether and how contextual uncertainty shapes their updating strategies. The pattern of results provides insights into the skills and mechanisms that enable children to learn correct word meanings under uncertainty.