Occlusion Protocol

This report describes a detailed experimental protocol to undertake evaluations of In-Vehicle Information System (IVIS) tasks using the Occlusion technique. Occlusion is a measurement technique to assess visual demand due to the use of visual or visual manual interfaces available to the driver while a vehicle is in motion. The Occlusion method assesses the visual demand and interruptability of an IVIS task using a means for intermittent viewing of the IVIS. For the purpose of this work, the Occlusion technique is used to help identify those IVIS tasks that require excessive levels of visual demand. The work presented here extends a recent ISO Occlusion standard with additional detail concerning aspects such as criteria for the exclusion of data and precise experimental wording. It also contains detailed descriptions of the methods used to calculate the key Occlusion metrics. This protocol has been developed to extend the ISO standard and to help ensure that there is consistency between assessment sites. It also acts as a reference tool for experimenters conducting Occlusion studies. In addition to the protocol, the report includes a proposed Demand Reference Level (DRL) which can be used to help identify which IVIS tasks require an unacceptably high level of visual demand from drivers.