Of a group of some 45 radar operators eye movement records were taken during 1 hour or 1/2 hour watches. The records were analysed in order to obtain information on the peculiarities of the search patterns of trained radar personnel. The main results were a) only about 50% of the P.P.I. display watched, is covered adequately, the outer 1/3 of the screen being seriously neglected. The inner 1/3 is watched a nearly sufficient proportion of the time. Subjects tend to neglect always the same parts of the screen. They differ very much among each other: range of coverage 33% to 8 %. b) Fixation times are relatively short, probably because of the very small number of targets presented. c) Eye movements sub tend some 3 degrees of visual angle. Large individual differences are found again; range 1 degrees. 5 to 4 degrees. 5. d) Some temporal effects are found, such as shrinking of the pattern in time. Some other points are mentioned as well. Comparisons with other investigations are made, and some conditions are put forward, to be taken into consideration when a training program is designed, in order to improve search strategies.
Abstract