We have analyzed the process by which people abandon their search in belief that they cannot find the necessary information. We are particularly interested in the reasons why they think that they have failed finding the target information. It is usually believed that information retrieval on computer databases is quite different from that in human networks, but there are some resemblances in the reasons why search is abandoned. There are several interesting observations in these processes. One is that even though people fail in getting the information they need, they sometimes do not realize their failure. We are building a model of human information retrieval in social settings using the analogy of computer database retrieval.