When several different people look at the same person,it's not unusual for each of them to see different things;when you alone observe one behavior or one person at two different times,you may see different things.The following are but some of the factors that lead to these changing perceptions . (1)Each person's perceptions of others are formed by his or her own cultural conditioning education,and personal experiences. (2)Sometimes perceptions differ because of what we choose to observe and how we deal with what we've observed.It is not necessarily true that person's perception is based on observations of a particular person.Your observations may be totally controlled by what others have told you about this person;or you may focus  primarily on the situation or role relationship.Most people do not use the same yardstick to measure their parents,their friends and strangers. (3)Sometimes we see only what we want to see or don't see what may be obvious to others because of our own needs,desires,or temporary emotional states.This is a process known as selective perception.Selective perception is obviously more difficult when contradictory  information is particularly obvious,but it can be done.We can ignore the " _ ".He's basically a good boy so what I saw was not shoplifting. We can reduce the importance of the contradictory information--All kids get into mischief .Taking a book from the bookstore isn't such a big deal."We can change the meaning of the contradictory information." It wasn't shoplifting because he was going to pay for it later. Observation of the same person by two people at the same time may differ because   _  .
their measuring yardsticks are not the same either of them may be slow to catch information the time for observation is not long enough each of them uses different language to express his/her impressions