Icons vs. Alphanumerics in Pilot-Vehicle Interfaces

The effects on performance from the use of icons and alphanumerics in pilot-vehicle interfaces were investigated in an experiment. Varying numbers of single status display indicators were presented in both iconic and alphanumeric formats in fixed and random display positions across three levels of difficulty. Subjects' ability to maintain a tracking task while concurrently searching and selecting appropriate display indicators was tested. Results indicated that for all numbers of indicators presented, icons produced faster search and selection reaction times. Significant interactions were also found for format type and difficulty level. Questionnaire assessment revealed that subjects preferred the iconic to the alphanumeric formats. Implications for the design of aircraft interfaces and further research suggestions are discussed.