Department of Psychology, University of Warwick, Gibett Hill Road, Coventry, CV4 7AL, UK,
Psychon Bull Rev. 2013 Oct;20(5):1023-31. doi: 10.3758/s13423-013-0422-3.
How do changes in choice-set size influence information search and subsequent decisions? Moreover, does information overload influence information processing with larger choice sets? We investigated these questions by letting people freely explore sets of gambles before choosing one of them, with the choice sets either increasing or decreasing in number for each participant (from two to 32 gambles). Set size influenced information search, with participants taking more samples overall, but sampling a smaller proportion of gambles and taking fewer samples per gamble, when set sizes were larger. The order of choice sets also influenced search, with participants sampling from more gambles and taking more samples overall if they started with smaller as opposed to larger choice sets. Inconsistent with information overload, information processing appeared consistent across set sizes and choice order conditions, reliably favoring gambles with higher sample means. Despite the lack of evidence for information overload, changes in information search did lead to systematic changes in choice: People who started with smaller choice sets were more likely to choose gambles with the highest expected values, but only for small set sizes. For large set sizes, the increase in total samples increased the likelihood of encountering rare events at the same time that the reduction in samples per gamble amplified the effect of these rare events when they occurred-what we call search-amplified risk. This led to riskier choices for individuals whose choices most closely followed the sample mean.
选择集大小的变化如何影响信息搜索和随后的决策？此外，信息过载是否会影响较大选择集的信息处理？我们通过让人们在选择之前自由探索一系列赌博，来研究这些问题，每个参与者的选择集数量增加或减少（从两个到 32 个赌博）。选择集的大小影响了信息搜索，参与者总体上采集了更多的样本，但采集的赌博比例较小，每个赌博采集的样本也较少。选择集的顺序也影响了搜索，如果参与者从较小的选择集开始，而不是从较大的选择集开始，他们会从更多的赌博中采样，并总体上采集更多的样本。与信息过载不一致的是，信息处理在选择集大小和选择顺序条件下似乎是一致的，可靠地倾向于样本均值较高的赌博。尽管没有证据表明存在信息过载，但信息搜索的变化确实导致了选择的系统变化：从较小的选择集开始的人更有可能选择预期价值最高的赌博，但仅在选择集较小时如此。对于较大的选择集，总样本的增加增加了遇到稀有事件的可能性，而每个赌博样本的减少放大了这些稀有事件发生时的影响——我们称之为搜索放大的风险。这导致那些选择最接近样本均值的个体做出更冒险的选择。
