Concentration ratio measurement device and program

A presentation device presents an object to be recognized to a test subject. An input device receives input from the test subject of a response to a work problem which is mental work with respect to the object to be recognized. The work problem is formed from work wherein is extracted a prescribed plurality of types of cognition elements which the object to be recognized encompasses, and work wherein is selected, from a quantity of choices wherein selection items which are set for each cognition element are combined, a choice which conforms to the cognition elements which are extracted from the object to be recognized. An evaluation device comprises a work storage unit which records as work information a response time from the time when the object to be recognized is presented in the presentation device to the time when the response is inputted into the input device. The evaluation device further comprises an evaluation computation unit which computes an evaluation value of the subject's concentration ratio from a statistical quantity of the work information which the work storage unit has recorded while presenting in the presentation device a plurality of instances of the objects to be recognized.