图形表征的物理突显性对风险回避行为的影响

The Impact of Physical Salience of Graphical Displays on Risk Avoidance Behavior

本研究通过操纵星号图的大小及相对大小来改变星号图的物理特征,并设数字条件为对照组,以进一步检验图形效应(即图形会比数字激发个体更强的风险回避行为)并探讨图形物理特征的突显性对风险回避行为的影响。结果发现,首先,星号图一般会比数字激发个体更强的风险回避行为;其次,无论是否突显星号图的整体面积,同比例地变化星号图的大小未能改变个体的风险回避行为;最后,当突显星号图的整体面积时,星号图的相对大小对个体的风险回避行为具有显著影响。结果表明,即使通过变化与表征数量信息相关较小的物理特征(星号图的大小),也可以改变个体的风险回避行为,相关结果可用决策与判断领域中的双系统模型加以解释,也进一步展示了人类在决策与判断过程中的非理性现象。

By displaying a risk reduction of 50% graphically rather than numerically, Stone, Yates, and Parker （1997） significantly increased professed risk- avoidant behavior. The purpose of this research was to re -examine the graphical effect by （de）compressing the area of asterisks and explore the effect of physical salience of graphical c,isplays on risk avoidance behavior. Following the former methods, the participants were told that with ＂Standard Tires＂ 30 out of 5,000,000 people would be expected to suffer a serious injury. Then the participants were informed about ＂Improw^d Tires＂ which is identical to Standard Tires except for the fact that it reduces the risk to 15 out of 5,000,000. In the first experiment, the number of people suffering a serious injury was dis- played either numerically by the numbers ＂30＂ and＂ 15＂ or graphically by means of stick figures （the compressed asterisks and the de- compressed asterisks）. The results of experiment 1 showed that the asterisks format usually lead to greater risk avoidance compared to the numerical display, and when the relative ratio was kept constant, the manipulations for the areas of graphical displays did not influ- ence risk -avoidant behavior significantly whether the whole asterisks＇area was highlighted or not. In experiment 1, the relative ratio of the whole areas for two asterisks （representing the injury risk for standard tires and improved tires respectively） was always 2：1 ; and in experiment 2, the relative ratios of the areas for two asterisks were changed. The results of experiment 2 indicated that the relative ratio of the areas for asterisks graphs had a significant effect on risk avoidance behavior with highlighting the variation of the whole area by adding the shadow, and people were willing to pay more money for reducing a negative risk in the asterisks display with high relative ra- tio （4.5 ： 1 ） than in the asterisks display with low relative ratio （ 1 ： 2 ）. 3＇he results of experiment 2 also showed that the graphical effect did not exist in the condition of low relative ratio asterisks display highlighting the variation of the whole area, which did not differ from the numbers condition in the consumers＇willingness to pay for the improved toothpaste. The present study further demonstrated a violation of descriptive invariance by manipulating the spatial representation of the op- tions. The results indicated that even changing the physical attribute （the anna of asterisks） that is unimportant for presenting numerical information can influence the risk avoidance behavior, which further indicated the irrational phenomenon in risk judgment. Specifically, （de） compressing the area of asterisks could change people~ risk avoidance, the larger for the area of the asterisks graphical representa- tion highlighting the variation of the whole area, the more money people were willing to pay for the improved toothpaste. When the graphical area was compressed, this graphical format was not more effective than its numerical counterpart in inducing risk - avoidant behavior. Two system theories in judgment and decision making can be used for explaining the results in the present studies.