The Influence Of Evaluation Mode And Reward Amounts On Ambiguity Aversion And Visual Attention Distribution

The risk scenario is that the probability of an event occurring is known,for example,a red ball is drawn from a urn containing 50 red balls and 50 black balls;the ambiguity scenario means that the probability of occurrence of the event is not clear,but only within a certain range inside,for example,a red ball is drawn from a urn containing 100 red balls and black balls.The ambiguity aversion phenomenon in the separate/joint evaluation mode means that the individual makes a preference for the risky event when jointly assessing the risky event with clear probability and the ambiguous event with unclear probability,and the preference disappears in the separate evaluation mode.Fox and Tversky(1995)first studied the ambiguity aversion phenomenon using the separate/joint evaluation mode,and found that individuals showed obvious ambiguity aversion phenomenon in the joint evaluation,while the ambiguity aversion phenomenon disappeared in the separate evaluation.Moreover,they also used real money to study this subject and obtained the same results.In the following studies,many researchers found that many factors affecting ambiguity aversion also explored how much money was given to the subjects in the risk scenarios and the ambiguity scenarios to enable the subjects to appear ambiguity neutral,that is,to select risk scenarios and the difference in the number of participants in the ambiguity scenario was not significant.However,there is no scholars to compare the effects of different reward amounts in the separate/joint evaluation mode and its attention distribution in the same risk and ambiguity decision scenarios,and whether this attentional allocation is affected by time pressure.In summary,this paper explores the individual's attention to the distribution of ambiguity aversion under different evaluation modes,reward amount and time pressure in the decision-making process through three experiments.The purpose of the first experiment was to study the influence of the reward amount on the ambiguity aversion and the visual attention distribution of the subjects under different evaluation modes,including two sub-experiments.The purpose of Experiment 1a is to explore the impact of the amount of rewards in the ambiguity aversion phenomenon in the individual decision-making process.The experiment used 2(reward amount: high vs.low)× 2(decision scenario: risk scenario vs.ambiguity scenario)two-factor subject-within experiment design.The independent variables are the reward amount and the decision scenario;the dependent variable is the likelihood assessment of the subjects selecting different decision scenarios.The purpose of Experiment 1b was to explore the effect of reward amount on ambiguity aversion of risk scenario or ambiguity scenario and the distribution of visual attention in the decision process in different evaluation modes.Experiment 2 used 2(evaluation mode: separate vs.joint)× 2(decision scenario: risk scenario vs.ambiguity scenario)× 2(reward amount: high vs.low)three-factor mixed experiment design,in which the evaluation mode was a between-subject factor and option attribute and reward amount were within-subject factors.The dependent variables were participants' evaluations and the eye movement indexes,such as the number of gazing points and the gazing time of area of interest.The purpose of Experiment 2 was to explore,in the joint evaluation mode,whether changing gazing time of options can eliminate ambiguity aversion with reward or in different evoluation modes and to explore change of eye movement.The experiment used 2(time pressure scenario: no vs.yes)×2(decision scenario: risk scenario vs.ambiguity scenario)× 2(reward amount: high vs.low)three-factor mixed experiment design,in which the experimental condition was between-subject factor,option attribute and reward amount were within-subject factors.The dependent variable were participants' evaluation and the eye movement indexes,such as the number of gazing points and the gazing time of area of interest.Through the above two experiments,we can draw the following conclusions :(1)under the joint evaluation mode,there is an ambiguity aversion when reward is provided,to be precise,under the condition of high reward,the participants tend to give higher value of the risk scenario,while under the condition of low reward,however,they tend to give higher value to the ambiguity scenario.In the separate evaluation mode,there exists no ambiguity aversion;(2)in both evaluation modes,participants show more gazing points and gazing time on ambiguity scenarios;(3)By manipulating the time pressure of scenarios,the ambiguity aversion can be eliminated in both evaluation modes and when reward is provided.