There are several points at which inaccurate or biased data can be introduced into clearance rates. For example, many crimes go unreported and multiple crimes are often committed by the same individual who may be arrested for only one of them. Yet official crime and arrest statistics cannot take these unknown factors into account. Measuring the percentage of cleared crimes against the number of crimes committed in a given period and comparing them against statistics for a second period can be misleading since the number of crimes committed is not constant. Also, changes in the way statistics are tallied over the years make long-term comparisons difficult and unreliable. Furthermore, clearance rates for some types of crime (e.g., murder) are much higher than those for other types. Therefore, the ratios of types of crimes committed during the year can affect the clearance rates. Finally, the ability to clear crime depends greatly on the quality of information about the crime. If the victim is the reporter and reports in a timely manner, clearance is more likely than if a nonvictim reports a discovered crime some time after its occurrence. To examine some of these statistical problems with clearance rates, clearance rates and data on reported residential burglaries for the years 1968 and 1978 were compared. In 1968, 2,234 residential burglaries were reported, and a clearance rate of 17 percent was realized. In 1978, 4,725 burglaries were reported and 7 percent cleared. Although a large difference in percentage cleared is apparent, scrutiny of the statistics indicate that the crimes were not comparable in all respects. For instance, the 1968 crimes were much more likely to be committed by younger persons and more likely to be committed in groups. Group crimes have a higher clearance rate than crimes committed by single individuals. In addition, convictions in 1978 were considerably down from 1968, affecting the determination as to whether a crime has been cleared. Additional differences in the two years' statistics are noted. Study data and 36 references are provided.