To study crime, sociologists need to know how much there is. This is harder than it sounds, because a great deal of crime is never recorded. Sociologists use three main sources, each with strengths and weaknesses.
Official statistics
Official statistics are records collected by the police and courts. They are cheap, cover the whole country and can be compared over years. However, they only include crimes that are reported to the police and then recorded by them. Many crimes are left out, so the figures are incomplete.
Victim surveys
A victim survey asks a large sample of people whether they have been a victim of crime, whether or not they told the police. This uncovers crimes that were never reported. Its weakness is that people may forget incidents, may not know a crime occurred, or may not wish to discuss it.
Self-report studies
A self-report study asks people, anonymously, about crimes they have committed themselves. This reveals offences the police never discovered. Its weakness is that people may exaggerate, hide the truth, or misremember.
The dark figure of crime
The crime that is never reported or recorded is called the dark figure of crime. Crimes may go unrecorded because:
- The victim thinks it is too minor to report.
- The victim fears they will not be believed or helped.
- There was no victim who noticed, or no witness.
- The police decide not to record it, perhaps judging it too small.
Comparing the sources
Because each method captures different crime, the three sources rarely agree. Victim and self-report studies usually reveal far more crime than the official figures, which is strong evidence that the dark figure is large. By comparing all three, sociologists build a fuller and more trustworthy picture than any one source could give alone.
Because of the dark figure, no single source gives a complete picture, so sociologists compare all three.