On subjectivity in the judging of acoustic records; comparison of degree of homogenity in allocation of echo values by different teams

Abstract

On four fish abundance estimation surveys in the Barents Sea, january-february 1993, the acoustic records were judged by two independent teams. We have analyzed the degree of homogenity in allocation of echo values to various species by the different teams. In general the average echo value allocated to a species was rather similar, but significant and noticeable differences were detected. Studies of the allocation in a one-to-one and time scale revealed greater variations, but still a reasonable degree of similarity in judgement by the different teams. The reason for variation in allocation of echo values to various species among different teams are discussed.