How Chess Expertise Reshapes Event Segmentation
Description
How do chess players perceive events in a chess game, as these events unfold in real time? The study builds upon the hierarchical bias hypothesis, stating that observers instinctively segment activities in alignment with a partonomic hierarchy. Eighteen participants (nine experts, nine novices) watched chess game videos and identified event boundaries at both fine and coarse grains. Data were analysed using discrete and continuous methods as well as an agreement index. Experts identified roughly twice as many boundaries as novices at both grains, showed descriptively but not significantly higher within-group agreement on boundary placement than novices (mean Agreement Index 0.607 vs. 0.506), and produced fine and coarse boundaries that aligned into a partonomic hierarchy more strongly than chance and more strongly than novices did. Verbal descriptions further showed that experts produced markedly more action-coded vocabulary than novices (9.8 vs. 2.1 terms per description). However, when descriptions containing such vocabulary were compared directly, experts and novices distributed it between basic-movement and higher-order strategic content in similar proportions. Expertise effects were uniform across grains, inconsistent with the specific prediction that differentiation would dominate at the fine grain and unitization at the coarse grain, though the present data cannot rule out joint contributions of both mechanisms to expert event representations. The results extend event segmentation research to a strategically cumulative domain and replicate the Zacks et al. (2001b) alignment effect with an additional expertise interaction.