There are a number of ways in which individuals, the community and governments know about crime, and there are a number of different sources of statistics on crime. Users may ask which of the various statistics available are the 'right' ones. However, it is not a simple process to reduce such a complex social issue to a single set of numbers.
Statistics need to be well understood in order for them to be useful in making informed decisions. Part of this understanding comes from a knowledge of the process by which particular events are recorded and eventually reported back to users. The Australian Bureau of Statistics (ABS) maintains national collections on crime victimisation sourced from two different areas: administrative records obtained from state and territory police agencies and victimisation data obtained through surveys of individuals in the Australian community. In some instances the results may provide a different picture of crime in the community, with administrative data indicating a trend in one direction and personal experience indicating the opposite.
The expectation that different sources of crime victimisation statistics should produce similar figures forms the basis that one source or the other is wrong. Such expectations arise out of the false belief that different data sources are always measuring the same thing, and are utilising the same methodologies. The reality is that the different data sources often use different methods and are producing different sets of crime victimisation indicators.
The full extent of crime is unlikely to ever be captured, and it is for this reason that we often hear of the 'dark figure' of crime (Coleman & Moynihan, 1996). The 'dark figure' refers to the volume of crime that is not officially recorded. For example, one person's interpretation of an action as a crime may not be the interpretation of another, or someone may be a victim of a crime but never notify anyone of their experience of the crime. Therefore, it is difficult to quantify all differences, but qualitative assessments can aid in understanding differences between sources of crime victimisation data.
The main aim of this paper is to increase community understanding of the nature of crime measurement in Australia and why the findings from different data sources may differ:
- section 2 outlines national crime victimisation statistics available from several different sources in the Australian context
- section 3 draws comparisons between the statistics from these sources
- section 4 describes methodological differences between survey sources
- section 5 describes the possible impacts of the methodological differences between the survey vehicles.
Through sections 3, 4 and 5 the scope and definitions of the data from various collections is progressively adjusted to assist in comparisons.
The paper concludes with a summary of the main points raised throughout.