MAP-01-011 HFI Technical Guide - Human Factors Integration ...

Annex 3 – HF Techniques, Methods and ToolsA3.7.2Crew Awareness Rating Scale (CARS)The Crew awareness rating scale (CARS) technique is a situation awarenessassessment technique that has been used to assess command and controlcommanders SA and workload.The CARS rating comprises two separate sets of questions based upon the threelevel model of SA. CARS is made up of two subscales, the content subscale andthe workload subscale. The content subscale consists of three statementsdesigned to elicit ratings based upon ease of identification, understanding andprojection of task SA elements (i.e. levels 1, 2 and 3 SA). The fourth statement isdesigned to assess how well the participant identifies relevant task related goalsin the situation. The workload subscale also consists of four statements, whichare designed to assess how difficult, in terms of mental effort, it is for theparticipant in question to identify, understand, project the future states of the SArelated elements in the situation.• Advantages• The CARS technique was developed specifically for infantry exercises andhas been applied in that setting.• The method is less intrusive than on-line probe techniques such as theSAGAT technique.• CARS is a generic technique and requires minimal modification to be usedin other domains e.g. the MARS technique.• Quick and easy to use, requiring minimal training.• The CARS technique could potentially be used in conjunction with on-lineprobe techniques to ensure comprehensiveness.• CARS offers a very low cost assessment of SA and workload.• Disadvantages• Questions may be asked regarding the construct validity of the technique.It could certainly be argued that rather than measuring SA itself, CARS isactually rating the difficulty in acquiring and maintaining SA.• The technique has limited validation evidence associated with it. Thetechnique certainly requires further validation in military or infantry settings.• As the CARS questionnaire is administered and completed post-trial, it issubject to problems such as poor recall of events and forgetting on the partof the participants. It is apparent that participants are limited in theaccurate recall of mental operations. For lengthy scenarios, participantsmay not be able to recall events whereby they were finding it difficult oreasy to perceive mission critical cues.May 2006 Page A3-57 Issue 4