APPLICATION OF RESEARCH KNOWLEDGE TO PANEL LAYOUT PROBLEMS 



171 



and electronic performance, and the service- 

 ability of the equipment. It is only within 

 this framework that he can satisfy the re- 

 quirements of the human factor. For ex- 

 ample, sometimes he is hmited as to where he 

 can place a particular display because of the 

 size of the power unit needed to drive it. 

 Or, when the demands on space are too great, 

 certain controls and displays will have to be 

 placed beyond the practical working limits 

 of the operator or assigned to a second opera- 

 tor such as a co-pilot or flight engineer. 

 Whatever the case, specific engineering Hmi- 

 tations must be accepted in reahstic panel 

 design. Then, within these limitations, the 

 most efficient panel layout can be worked 

 out. Of course, with further engineering 

 advances, these Hmitations may be reduced 

 and some of the problems facing the students 

 of the human factor in panel layout may 

 be obviated. For example, if satisfactory- 

 booster systems can be devised to help in the 

 operation of controls, it may not be necessary 

 to place a lever in a position for maximum 

 pull. 



The Evaluation of Panel Layouts 



A second point that ought to be kept 

 uppermost in mind in applying our knowl- 

 edge of human capacities to panel design is 

 that the ultimate criterion is the efficiency 

 of operator's performance. Many factors 

 which determine the operator's efficiency 

 cannot be separated and studied in isolation. 

 But it is still possible to do experiments by 

 introducing changes in panel design that are 

 indicated by the study of human capacities 

 and objectively testing the performance of 

 the operator. The example of redesigning 

 the soldering operation is a good illustration 

 of this point. Several aspects in the ar- 

 rangement of the work situation were varied 

 at one time, but the only criterion of success 

 or failure of the changes was the output of 

 the operators. Methods of evaluating op- 

 erator performance in complex military' tasks 

 may not be as easy to devise as they are in 

 the case of simple, repetitive, assembly-fine 



jobs, but several techniques, described be- 

 low, have been successfully carried over from 

 industry (7, 8, 20, 28). 



Equipment in the Design Stage 



The best opportunity to apply our knowl- 

 edge of human factors in panel design comes 

 when the equipment is in the design stage. 

 A variety of procedures for incorporating 

 experimental data and principles into panel 

 design have been mentioned in the fiterature 

 (7, 20, 24, 34), but they may be summarized 

 and synthesized in a few brief points. At 

 the blueprint stage, a number of obvious 

 points can be checked: the purpose of the 

 equipment, the type and function of each 

 control and display, the overall dimensions 

 of the panels, the distance of controls and 

 displays from each other and from the op- 

 erator, the grouping of controls and displays 

 on the panel. It is a simple matter to deter- 

 mine whether any of the known principles of 

 panel design are violated, and corrections 

 are easily made at this stage of design. Once 

 all that is possible has been done with the 

 blueprint, the next step is to construct mock- 

 ups of the equipment to answer further ques- 

 tions that are bound to come up about 

 alternative types of design. For example, 

 in the design of aircraft cockpits, it is now 

 possible to use a rather elaborate mock-up 

 arrangement consisting of the Universal Test 

 Seat developed at the University of Michi- 

 gan and the Beindorf Fixed Preflight 

 Trainer, which has typical aircraft controls 

 and displays (32). The test seat permits 

 wide variation in the position of the operator, 

 and the trainer affords a reahstic cockpit 

 atmosphere in which the arrangement of con- 

 trols and displays may be varied. Actually, 

 simpler mock-ups are satisfactory for many 

 purposes. For example, in studies of radar, 

 simulated combat information can be pre- 

 sented on a scope and the speed and accuracy 

 of subjects operating experimental control 

 panels can be determined. Basically, all 

 that is needed in a mock-up is a dummy 

 panel of proper dimensions in which the con- 



