A set of slides used in a presentation to the Forth National Justice Modelling Workshop at Griffith University, Brisbane Australia by David Harpham (Department of Corrections, NZ) in July 2008.
Abstract
New Zealand Corrections’ data has been reduced to a set of simplified longitudinal offender histories for all NZ Corrections managed offenders since 1980. The specification and utility of this data is explored with some examples giving new insights into the evolving NZ offender population.
A simple graphical timeline/sparkline method for describing longitudinal offender histories is provided and some examples of colourful offender histories explored. Included are typical collections of timelines of offenders dealt with by Corrections and graphical exploration of offender typologies.
The use of a rich graphical description of offenders is discussed in relation to understanding intervention evaluation and complementing and communicating statistical results.
The concept of a national offender pool is introduced and a graphical representation of the pool of New Zealand offenders explored.
Conclusions reached include:
· that the NZ offender population is aging
· that the offender net is being thrown more widely
· that the offender net is being thrown faster
· that the overall number of active offenders is dropping per head of population, but the proportion under current management increasing
· that the rate of creation of new chronically antisocial offenders is relatively constant
· that the use of timelines enables improved comprehension of the criminal justice arena