Plavyak and Sahin (2010) believe the authentication serves the purpose of authenticating users of a particular named security system through the use of passwords as well as user ID. Authentication is a common process found in use authentication systems and helps in the ascertaining of access authorization before granting access to access to systems. However during the process of authentication, some errors may occur during the process which can be regarded as false positives and false negatives. In authenticating users, false negative occur a system rejects an authentic user of the system who should have been accepted by the system. On the other hand, a false positive does occur when a system accepts an imposter who ought to have denied entry into the particular system (Bolle, 2003). In some cases, a false negative is tagged as type I error while a false positive is tagged as type II error (Zhang, 2002).
Harris (2007) argues that cross over rate is a variable that is often used in comparing the effectiveness of various used authentication systems such as biometric systems. This variable is represented in form of percentage which denotes the rate at which the false rejection rate equals the false acceptance rate. This variable is influenced by a number of environmental which may increase or reduce the degree of cross over error rate. Woorward, Orlans and Higgins (2003) identified weather and heat as elements of the environment that increase the cross over rate in authentication systems. Use training and education can also influence the rate of success of matching users. The use of protective gear such as gloves does influence the cross over error rate.
Pham (2005) affirms that calibration is often done to systems in order to reduce errors. Systems are also calibrated in order to avoid instances of failure to enroll where user data are not captured by the system (Cannon, 2008). Calibration of cross over error rate creates a balance between speed and efficiency of the system in use in any organization.