• Home
• Index
• Glossary
• Site Map
• User Guide

Home > Evidence Handling Procedures > Associative Evidence > Value of Associative Evidence > Frequency of Occurrence

The significance of associative evidence also depends on the frequency of occurrence of the measured attribute in the environment.

For example, the frequency in various human populations (Caucasian, Negroid, Mongoloid, etc.) of the DNA composition at each of the thirteen locations (known as the thirteen core loci) has been measured.  The frequency of the full profile in the population as a whole can therefore be calculated.  The accepted process for doing this and deriving a numerical description of the rarity of the DNA profile is complex, but, in essence, a DNA profile from the thirteen core loci is unique (other than for identical twins). 

In contrast to the biological diversity between individuals, the tight quality control of the manufacturing of glass would lead us to expect a high degree of similarity in the physical and chemical properties of glass produced in a single batch.  However, batch-to-batch variation and the small within-batch differences referred to previously mean that it has not been possible to establish population databases for glass that are as useful as those for DNA. 

< Previous Page  ::  Next Page >