Most crimes committed in the country are not reported to local police departments. Of crimes committed in the country, a much greater proportion have been reported to local police departments in recent years than were reported 20 years ago. Not all of the citizens selected for the series of independent surveys had been the victims of crime. In the series of independent surveys, many of the respondents did not accurately describe the crimes to which they had fallen victim.
Criminologist: According to a countrywide tabulation of all crimes reported to local police departments, the incidence of crime per 100, 000 people has risen substantially over the last 20 years. However, a series of independent surveys of randomly selected citizens of the country gives the impression that the total number of crimes was less in recent years than it was 20 years ago.
Which one of the following, if true, would most help to resolve the apparent discrepancy described by the criminologist?