時間壓力、屬性數量及選項數量變化情況對決策行為之影響研究

Studies on Decision Behavior under the Situation of Time Pressure, Numbers of Attribute and Numbers of Attribute and Numbers of Alternative

本研究以Beach & Mitchell（1978）的「損／益」模式為研究架構，採用歷程追蹤取向之訊息板法，探討決策者在選擇歷程中的決策行為。本研究主要目的有二：（1）探討作業複雜性對訊息處理的影響效果，亦即探討時間壓力、屬性數量及選項數量變化對訊息搜索的深度、訊息搜索的次序之交互作用；（2）分析作業複雜性與決策策略運用組型的關係。實驗以45名大學生為受試者，並採用3（時間壓力）×2（屬性數量）×2（選項數量）三因子混合設計來進行，其中第二和第三因子為受試者內設計。依變項為訊息使用量、訊息搜索次序之PI指數與搜索的變異性（SD）、及決策策略使用次數。研究結果發現：（1）屬性數量或選項數量的變化會影響搜索的深度，當屬性或選項的數量增加時，受試者使用較少的訊息；（2）屬性數量與選項數量在PI指數上有交互作用效果。亦即當受試者在進行4×8選擇作業時，訊息搜索以屬性內搜索方式為主，但在進行8×8選擇作業或4×4選擇作業時則不使用同樣的搜索方式。另一方面，當屬性數量或選項數量為八個時，搜索的變異也隨之加大。（3）屬性數量或選項數量的變化與決策策略運用組型有關，不管屬性數量或是選項數量增加時，受試者大多使用非補償性模式的策略，尤其是以連言策略為主。最後，討論本研究中作業複雜性對決策行為影響的涵意，並從研究方法的觀點對未來的研究方向提出建議。

Process tracing approach was adopted to explore the personal decision behavior under choice situation, with Beach & Mitchell (1978)’s cost-benefit model as the framework. Namely, the purposes of this study were twofold: (1) To investigate the effects of task complexity on personal information processing, i.e., to analyze the interaction effects of time pressure, the number of attributes, and the number of alternatives on the depth and the sequence of searches. (2) To explore the reationship between task complexity and the patterns of decision strategy. Forty-five undergraduates served as subjects. A 3 (Time Pressure)×2 (Number of Attributes)×2 (Number of Alternatives) mixed design was used, with the second and the third as within-subjects factors. The dependent variables were the amount of information used, Payne Index, variability of search (SD), and the frequency of each decision strategy. The findings were as follows: (1) Both the number of attributes and the number of alternatives had effects of the depth of search. As the number of attributes or the number of alternatives increased, subjects searched less amount of information. (2) There was significant interaction effect between the number of attributes and the number of alternatives, when Payne Index was used. In other words, when subjects were making 4×8 choice task, information search was dominated by intra-dimensional search; however, the same information search way was not found when making 4×4 or 8×8 choice task. On the other hand, the variability of search increased when eight attributes or eight alternatives were in the choice set. (3) The search used was related to the number of attributes and to the number of alternatives. When the number of attributes or the number of alternatives increased, subjects used many noncompensatory strategies of which the conjunctive strategy was the dominant mode. Finally, theoretical implications for effects task complexity on decision behavior were discussed. The suggestions for the terms of research method were also discussed.