Respondents may forget when reporting their past behavior, so human memory is also a source of response errors. When respondents have impaired memory or do not respond accurately, this is termed response error or faulty recall. Memory is subject to selective perception (noticing and remembering what we want to) and time compression (remembering events as being more recent than they actually were). Respondents sometimes use averaging to overcome memory retrieval problems, for example, telling the interviewer what is typically eaten for dinner on Sunday, rather than what was actually consumed on the previous Sunday