Modeling adaptation behavior to driving simulators and effect of experimental practice on research validity

Driving simulators provide a safe and controllable environment, where different aspects of driving can be analyzed without risking other road users’ safety. However, as simulators cannot precisely replicate real-life scenarios, there has been an ongoing debate about how well the results of simulator studies can be generalized to the actual world. Many studies have compared the outcomes of field experiments and those involving their simulated counterparts in order to test the validity of the research on driving simulators. In nearly all cases, however, the researchers made comparisons without analyzing the underlying psychological explanations behind potential differences. This thesis will discuss why adaptation, or the process by which participants learn how to interact with a simulator, is an important precondition of validity in simulator experiments. Data collected from several experiments revealed that adaptation can distract participants from performing the main task and can systematically bias the results of the experiments. The current study demonstrated that although most researchers provide a practice session before the main scenario, there is no unified approach to determine the characteristics of practice scenarios. The practice sessions vary greatly both in duration and form; and no method has been formulated to verify that a participant has in fact adapted at the end of the practice session. To address these shortcomings, this thesis provides a methodology that mathematically models the learning pattern of subjects to steering and pedals, which can also help identify the adapted and non-adapted subjects at the conclusion of practice scenarios. A comparison of the results of two groups of subjects (control and experiment) showed that adaptation to a driving simulator is largely task-independent. This study analyzed the effect of the practice scenario design on the performance of participants in the main task, which led to the observation that during the main scenario participants tend to continue focusing on the subskills they learned during the practice scenario. Based on the results of these experiments, the thesis provides recommendations on how to measure adaptation and also how to improve the quality of the practice scenario design to minimize any unwanted impact on the main scenario.Applied Science, Faculty ofCivil Engineering, Department ofGraduat