The document describes two types of personality - Type A and Type B. Type A personalities are highly competitive, struggle with multiple tasks, have a strong sense of urgency and impatience. They easily lose their temper and interrupt others. Type B personalities are more patient, less competitive, contemplate issues carefully and have a relaxed approach to life. It also lists biological, environmental, cultural and situational factors that determine personality, such as heredity, family atmosphere, economic conditions and locus of control. Finally, it provides some methods to minimize errors in surveys such as checking the sampling process, using a pilot survey, providing training to staff and checking data analysis.