Every psychologist working in the field of applied psychology seeks to improve the quality of the service that he renders. He may do this in several ways: (1) by studying and analysing the tools of his profession, i.e. tests, questionnaires, interviewing techniques, experimental and statistical methods, etc.; (2) by professional growth through formal or informal advanced study and by personal development through a more significant understanding of himself; (3) by creating new tests, techniques, methods or more inclusive, integrated hypothesis and theories; (4) or, by a combination of the methods briefly listed.
