难度-价值权衡情境下的项目选择及其眼动特征

Item Selection in Difficulty-Value Trade-Off Situations and Its Eye Movement Characteristics

本研究采用行为和眼动技术,通过设置难度-价值权衡情境,考察在学习时间有限的条件下,学习者如何选择学习项目,以及该过程如何发生。结果发现:(1)被试更多选择得分期望最高的项目,而非分值最高或最简单的项目。(2)选择学习项目的过程不存在计算项目得分期望的过程。结果表明,学习者项目选择不仅基于难度或价值,而是会权衡难度和价值,选择得分期望最高的项目。该过程不符合补偿性决策理论的预期,与非补偿性理论预期一致。

Item selection is one of the most important indicators of the effectiveness of learning control. Early researchers focused on the influence of item difficulties on item selection. It is believed that learners will monitor the item difficulties, and choose to study the easier items first, especially when total study time is limited. Recently, researchers found that when facing materials with different values, learners choose to give priority to study the items with high value. However, when they came to the conclusion that learners will choose items according to their difficulties or values, they did not control the other factors strictly. In the present study, we want to know when facing items with different difficulties and different values, what kind of items will learners choose to learn, the easiest one, the one with the highest value, or the one with the highest expected return? And how does the selection process take place?In experiment 1, three items(each item contains a Spanish word and its corresponding Chinese translation) were presented on a 21-inch screen. One was the easiest(highest pass rate), one had the highest point, and the other one had the highest expected return(pass rate × point). Pass rate and point of the items were marked separately above and below the items. Participants were asked to choose one of the three items for the subsequent learning phase. In experiment 2, two items with different pass rates and different points were presented, and participants were asked to choose one from the two items for the subsequent learning phase. Eye movement data was recorded using an EyeLink 1000 Plus eye tracker sampling at 1000 Hz. All words were presented in white SimSun 21-point font, on a black background. If participants selected items by calculating the expected return of the items, there would be more saccades between different attributes of the same item than saccades between the same attribute of different items.The main results were as follows:(1) In Experiment 1, there was a significant effect of item type, F(1, 29) = 225.41, p <.001, ηp2 =.89. Participants chose more items with the highest expected return than other items(ps <.001).(2) In Experiment 2, there was no significant difference in first fixation index, proportions of dwell time, proportions of fixations and average pupil diameters between pass rates and points, ts ≤ 1.54, ps >.05.(3) In Experiment 2, there were more saccades between the same attribute of different items than saccades between different attributes of the same item, t(25) = 2.29, p <.0, Cohen’s d =.46.The findings suggest that when learners facing materials with different values and difficulties, their item selection is not only based on difficulty or value, but based on comprehensive consideration of difficulty and value. Furthermore, the comprehensive consideration is not done by performing an expectation computation, but by comparing the same attribute of different items. The results are compatible with uncompensated models.