Final answer:
The Army Alpha and Army Beta tests were pivotal in the history of psychometric testing by efficiently assessing the mental abilities of large numbers of military recruits during WWI, leading to advancements in personnel selection and the solidification of psychology in operational settings.
Step-by-step explanation:
During World War I, the Army Alpha and Army Beta tests were developed to screen and select enlisted men. The Army Alpha test was a written examination to measure mental abilities, while the Army Beta test was a non-verbal alternative for illiterate or non-English-speaking draftees. These tests marked a significant advancement in psychometric testing, providing a method to assess large numbers of recruits rapidly and helped lay the groundwork for future psychological testing methods, such as those for personnel selection and placement in both military and civilian sectors. The widespread use of these tests illustrated a practical application of psychological principles and solidified the role of psychology in operational settings.