Control group

  • The control group is the group of participants that do not receive the experimental treatment, but rather receive the standard treatment against which the experimental observations are evaluated and compared.

False positive

  • A false positive occurs when a clean breath sample is erroneously determined as containing alcohol.

Hardcore offender

  • The definition of a hardcore offender can be generalized to describe a specific group of resistant offenders who are also known as persistent drunk drivers, chronic drunk drivers, and repeat offenders. Hardcore offenders repeatedly drive after drinking and often drive with high blood alcohol concentrations of .15% or .20% or more. These individuals also appear relatively resistant to changing their behaviour.1

Hard suspension

  • Hard suspension means that a driver will not be permitted to drive for any purpose for a specific duration of time.


  • Randomization is a process in which individuals are assigned by chance to either the treatment group or the control group, thus giving each participant an equal chance of being assigned to either group and reducing the likelihood of bias (either scientific or personal).


  • Recidivism is the continued or habitual commission of an offence after an individual has been previously sanctioned or received treatment for committing a crime. 

Treatment group

  • The treatment group is the group of participants who receive an experimental treatment, and are usually compared to a control group.

1.Source: Beirness, D.J., Simpson, H.M., and Mayhew, D.R. (1998). Programs and policies for reducing alcohol-related motor vehicle deaths and injuries. Contemporary Drug Problems 25:553 – 578. Return to text