The campus safety committee has asked Professor Ibrahim to study bicycling on his campus. He trains two observers and has them observe at various points around campus. They record the number of cyclists and their safety. After completing the observational study, Professor Ibrahim sends a survey out to the entire campus about bicycle safety, and asks all bicyclists to respond. He finds a large difference between their reports of how safely they ride and what his observers found. What is a likely cause of this?

Socially desirable responding: The term "socially desirable responding" is also denoted as SRD, and is defined as the propensity of an individual to produce different positive self-descriptions. The status of the socially desirable responding lies in the specific clarification of encompassed psychological construct.

Socially desirable responding is considered as one of the types of response bias in which the candidates involved in a survey tend to respond in a way that is considered as favorable by others.

In the question above, the given statement's cause is socially desirable responding.