The document discusses the ASK theory of performance, where A=Attitude, S=Skills, and K=Knowledge. It states that skills can be acquired and knowledge can be gained through training and education. However, attitude is inherent and cannot be developed over a lifetime if it is initially missing or negative. The three elements together yield the best performance, but performance can still occur with just one element if attitude is present to blend with the other. As a manager, the most important goal in filling vacancies should be to find candidates with the right attitude, as skills and knowledge can then be developed through training. Evaluating a candidate's attitude is the most critical but difficult ability for a manager.