Research

Glossary

Control group - the control group is the group of participants who do not receive the experimental stimulus, in this case the ignition interlock, but rather receive the standard stimulus, e.g., a licence suspension, against which the experimental observations are evaluated and compared.

False Positive - a false positive occurs when the alcohol concentration in the body of the person delivering the breath sample is truly below the pre-set limit, but the device erroneously records it as if the person was above the pre-set limit. This can happen, for example, due to mouth alcohol, when the person delivering the breath sample recently drank alcohol or used mouth wash containing alcohol and did not rinse before blowing into the device.

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 - randomization is a process in which individuals are assigned by chance to either the experimental group (i.e., the offenders with an interlock) or the control group (i.e., the offenders without the interlock), thus giving each participant an equal chance of being assigned to either group and reducing the likelihood of bias, e.g., self-selection bias when offenders can choose themselves to which group they will belong (in such a self-selection scenario it is very likely that offenders who are a priori against the use of an interlock will choose to belong to the control group, while offenders who are a priori in favor of the use of an interlock will choose to belong to the experimental group and differences found between both groups can then be explained by other reasons than the influence of the experimental stimulus; this makes it more difficult to draw conclusions about the influence of the interlocks on offenders).

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

Experimental group - the experimental group is the group of participants who receive an experimental stimulus, in this case the ignition interlock, and are usually compared to a control group of participants who do not receive the experimental stimulus but rather receive the standard stimulus, e.g., a licence suspension, or no stimulus.

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^1. Source: Simpson, H.M., Beirness, D.J., Robertson, R.D., Hedlund, J.H. (2004). Hard core drinking drivers. Traffic Injury Prevention 5(3), pp. 261-269. Return to text