Humans are primarily visual creatures. Not all animals depend on their eyes, as we do, for most of the information received about their surroundings (the characteristics of human vision are discussed in Chapter 3). For example, we expect to recognize familiar people and surroundings in photographs, and television and movies are major sources of entertainment. Tests with college students indicate that they are predominantly visual learners (in spite of which, lectures are still the most common teaching mode). In a more specific instance, crime scene photographs are often critical in explaining physical evidence to a jury.