再探費茲定律：工作限制與視覺操弄對動作表現的影響

Fitts' law re-visit: Investigation of the task constraints and visual effects on movement performance

謝宗諭(Tsung-Yu Hsieh) ； 卓佩佩(Pei-Pei Cho) ； 劉有德(Yeou-Teh Liu)

《臺灣運動心理學報》 19卷2期 (2019/11) Pp. 75-94

https://doi.org/10.6497/BSEPT.201911_19(2).0005

摘要

費茲定律描述、解釋人類動作速度與準確度消長的現象，65年來廣受研究者的重視。然而此定律中的目標大小常與實際表現的終點分佈有所差異，也間接影響實際動作距離的長短。此外，呈現目標的方式也因視覺對瞄準工作的重要性，可能對費茲典範工作的表現有所影響。目的：探討費茲典範工作中，一、目標中心點的呈現對動作表現的影響；二、費茲難度指數與有效難度指數間的關係；三、終點變異性隨動作速度而改變的趨勢。方法：招募10名慣用右手的健康成年人，進行14種由不同距離、目標類型及目標寬度所組成的畫線工作情境，每種情境50次試作。所收集整理的時間與空間表現，除以變異數分析、t檢定進行統計考驗外，另以三參數指數函數進行空間變異性對動作速度的適配。結果：高難度工作的目標有中心點呈現時，較無中心點的工作有較小的終點變異性。目標寬度1公厘的有效目標寬度大於所設定的範圍；目標寬度10公厘與有效目標寬度沒有顯著差別；40公厘及80公厘的有效目標寬度皆小於實際的目標寬度。當動作速度增加時，終點變異性有以指數函數漸增的趨勢。結論：費茲典範工作中目標呈現的方式會影響動作表現，設定的難度指數也與有效難度指數呈系統性的變化。

關鍵字

速度與準確度消長 ； 有效難度指數 ； 動作變異性

並列摘要

For the past 65 years, researchers have applied the Fitts' Law extensively to understand the tradeoff of speed and accuracy of human movements. The literature, however, often showed discrepancies between the end points distributions and the target sizes that also indirectly lead to the different movement amplitudes. In addition, the arrangement of the target display may also affect the movement performance due to the role of the visual perception in carrying out the aiming tasks. Purposes: To investigate 1) the effect of displaying a dot in the center of the target, 2) the relation between the effective (Eff) and the Fitts' indices of difficulty (ID), and 3) the relation of the end points variabilities to the average movement velocities, under the Fitts' paradigm. Method: Ten right handed healthy adults performed 14 conditions of line drawing task with combinations of movement amplitude, target display, and target size. Each condition had 50 trials. The spatial and temporal performances of the tasks were analyzed using the ANOVA, t tests, and a 3-parameter exponential fit of the spatial variability to the average movement velocity. Results: The end points variability was significantly smaller for the dot-target than no-dot-target in the high ID conditions. The Eff target widths were greater than the goal target for the 1 mm conditions, no differences were found for the 10 mm conditions, and the Eff target widths were smaller than the goal targets that was 40 mm or larger. The end points variability increased as an exponential function of the average movement velocity. Conclusion: The movement performances may be influenced by the arrangement of target displays, and there is a systematic change of the Eff ID from the Fitts' ID.

並列關鍵字

speed and accuracy trade-offs ； effective index of difficulty ； movement variability

參考文獻

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