程式設計中的延伸認知-以眼動探討程式設計認知負荷

Abstract

在當代的程式設計中，整合開發環境中的語法上色(Syntax-Coloring)與自動完成(Auto-complete)兩功能在程式開發的過程中扮演了重要的輔助角色，然而，這兩項開發環境的輔助功能對開發者的影響還沒有被仔細探討過。本研究從「延伸認知」的角度切入，將語法上色與自動完成納入程式設計師的認知中，選定認知負荷探討此兩功能的影響，並以認知負荷生理測量中的眼動指標為主，搭配主觀自評認知負荷與衡量作答表現對照。

本研究在國立交通大學招募83名具有程式撰寫能力的受測者，實施第一部分測驗閱讀題型(Q1-Q3)探討有無上色之影響，以及第二部分測驗編輯題型(Q4)探討有無上色與有無自動完成之影響，實驗並使用Eyetribe眼動儀紀錄眼動資料。

實驗數據分析後，本研究在有無上色與有無自動完成對程式設計的認知負荷影響的探討中，並沒有得到所預想的結果，深入探討原因後發現程式設計先備能力難以控制、認知指標選取、程式設計眼動行為個體差異大與施測題目代表性等限制，未來建議實驗的設計改使用組內差異比較，這樣的方法解決不同受測者間程式設計能力難以控制，同時也排除程式設計中眼動指標的個體差異大。

本研究也嘗試利用四個程式設計任務進行組內比較，結果顯示，在假設順序效應無影響的條件下，將客觀認知負荷指標的各題答題率與眼動指標互相對照之下，「總凝視時間」與「平均掃視時間」兩眼動指標與答題率結果最一致，因此，往後在程式設計領域的認知負荷研究可以優先使用此兩指標，藉由眼動指標生理量測取得更客觀且更具有說服力的認知負荷。

In today's programming, "Syntax Coloring" and "Auto-complete" in Integrated Development Environment play an important role to developers. However, there hasn't been a study to discuss how these two features interact with developers. This research starts from the angle of "Extended Cognition", and regard "Syntax Coloring" and "Auto-complete" in developers' cognition. Objective cognitive workload measured by eye-tracking is chosen to be the main indicator.There are 83 participants with programming skills recruited from National Chiao Tung University. Three reading problems(Q1-Q3) and one editing problem(Q4) are conduted. In addition, the "Eyetribe" eye-tracker is used in this research.

In the result, there is no significant relation found between the two features and cognitive workload as expected. After in-depth exploration, four difficulties, "Background Knowledge control", "Cognitive Indicator", "Individual Differences" and "Research Material", are found to be the reasons. An attempt to analysis the data of Q1 to Q4 within subject reveals that "Total Fixation Time" and "Average Saccade Time" closely related to objective performance measurement of cognitive workload without regard of ordering effect. These two eye-tracking indicators can be used to obtain objective cognitive workload for researches in the future .