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Description
Human operators are more prone to errors under high-workload conditions. However, error-commission research in cognitive science has been limited to studying behavior in single-choice reaction time tasks, which do not represent the complex multitasking scenarios faced in the real-world. In the current paper, prior evidence for a cognitive error-monitoring mechanism was applied toward predictions for how humans would react after making errors in a more ecologically valid multitasking paradigm. Previous work on neural and behavioral indices of error-monitoring strongly supports the idea that errors are distracting and can deplete attentional resources. Therefore, it was predicted that after committing an error, if a subject is subsequently presented with two simultaneously initiated task alerts (a conflict trial), they would be more likely to miss their response opportunity for one task and stay tunneled on the other task that originally caused the error. Additionally, it was predicted that this effect would dissipate after several seconds (under different lag conditions), making the error cascade less likely when subsequent tasks are delayed before presentation. A Multi-Attribute Task Battery was used to present the paradigm and collect post-error and post-correct performance measures. The results supported both predictions: Post-error accuracy was significantly lower as compared to post-correct accuracy (as measured through post-trial error rates). Post-trial error rates were also higher at shorter lags and dissipated over time, and the effects of pre-conflict performance on post-trial error rates was especially noticeable at shorter lags (although the interaction was not statistically significant). A follow-up analysis also demonstrated that following errors (as opposed to following correct trials), participants clicked significantly more on the task that originally caused the error (regardless of lag). This continued task-engagement further supports the idea that errors lead to a cognitive tunneling effect. The study provides evidence that in a multitasking scenario, the human cognitive error-monitoring mechanism can be maladaptive, where errors beget more errors. Additionally, the experimental paradigm provides a bridge between concepts originating in highly controlled methods of cognitive science research and more applied scenarios in the field of human factors.
ContributorsLewis, Christina Mary (Author) / Gutzwiller, Robert S (Thesis advisor) / Becker, David V (Committee member) / Gray, Robert (Committee member) / Arizona State University (Publisher)
Created2021
Description
The choices of an operator under heavy cognitive load are potentially critical to overall safety and performance. Such conditions are common when technological failures arise, and the operator is forced into multi-task situations. Task switching choice was examined in an effort to both validate previous work concerning a model of task overload management and address unresolved matters related to visual sampling. Using the Multi-Attribute Task Battery and eye tracking, the experiment studied any influence of task priority and difficulty. Continuous visual attention measurements captured attentional switches that do not manifest into behaviors but may provide insight into task switching choice. Difficulty was found to have an influence on task switching behavior; however, priority was not. Instead, priority may affect time spent on a task rather than strictly choice. Eye measures revealed some moderate connections between time spent dwelling on a task and subjective interest. The implication of this, as well as eye tracking used to validate a model of task overload management as a whole, is discussed.
ContributorsZabala, Garrett (Author) / Gutzwiller, Robert S (Thesis advisor) / Cooke, Nancy J. (Committee member) / Gray, Rob (Committee member) / Arizona State University (Publisher)
Created2020
Description随着基金业近年来迅速发展，一位基金经理同时管理多只基金的“一拖多”模式成为了越发普遍的现象并引起广泛关注。但在学术界，这一重要行业现象尚未被充分讨论。为深入探讨基金经理“一拖多”模式的成因及业绩影响。本文搜集并整理了中国2008年到2018年的基金业数据，对该问题进行了系统探讨。首先，就基金被“一拖多”的原因看，研究发现：（1）基金公司有过度使用优秀基金经理的现象，基金经理从业时间越长、学历越高，则管理多只基金的概率越高。（2）现金流压力较小的基金更易被“一拖多”，债券型、基金的最小赎回份额较高以及个人投资者比例较低的基金现金流压力较小，被一拖多的概率更高。（3）基金公司的注册资本越高，成立时间越长，管理规模越大，其管理的基金被“一拖多”的概率就越高。
其次，本文探讨了基金经理“一拖多”的业绩影响，研究发现：（1）基金经理“一拖多”总体上降低了基金回报。（2）异质性分析显示，当基金所在企业成立年份较长、管理资产较高时，基金经理“一拖多”更易导致基金业绩回报显著下降。此外，当基金经理从业时间较短、管理的基金组合的风格集中度较低时，这一效应更加明显。（3）基金“一拖多”模式不仅通过分散经理精力降低基金回报，久经锻炼的基金经理也会利用自身经验和知识弥补甚至追回精力分散效应的损失。
最后，本文还试图研究基金经理的最优基金管理数量。研究发现：基金业绩首先会随着基金经理同时管理基金的个数增加而下降，但随着管理基金个数的进一步增加，基金业绩会有所回升。总体上，基金经理管理的基金数量在10支左右时达到收益率最劣势，当管理基金的数量在17支以上时，经验复制效应带来的收益将超过精力分散效应带来的损耗，达到效应平衡点。
本文补充了当前学术界在基金经理“一拖多”现象上的研究，并根据研究结果提出了对应的业界实务建议。
ContributorsFan, Wei (Author) / Zhu, Hongquan (Thesis advisor) / Yan, Hong (Thesis advisor) / Zhang, Huibing (Committee member) / Arizona State University (Publisher)
Created2021