The survey design is one with which we are all familiar. Surveys aim to obtain information in a standard form from large samples. There are several large government surveys which are regularly conducted, for instance the Census and the British Crime Survey. Analysis of this data assesses trends, looks for patterns and makes comparisons between subgroups within the survey. An important feature of surveys is the aim for representativeness of coverage, and therefore the sampling procedures chosen are critical. Data is frequently collected by questionnaire, is usually quantitative and is pre-coded and amenable to analysis by computer.
The large survey as such is relatively rare in probation evaluation, although section 6.4 describes a Home Office survey of offenders.
The systematic recording of ordinary practice can be a useful evaluation method. An example is assessment, a task routinely undertaken by probation officers in their day-to-day work. If a standard procedure is used across a number of cases this data can be summarised and sub-groups compared to provide more knowledge about the characteristics of those being assessed. If detail about the result of that assessment is also collected in a standard way, whether as a supervision plan, or as a proposal for a certain type of disposal, or acceptance on to a drug programme, this can provide information about the assessment features of those with different results.
This can be a very simple and powerful way of identifying potential discriminatory practice. For instance, results that showed that black drink drive offenders were referred proportionately less than white offenders for a drink driver programme would suggest possible discriminatory practice that required further investigation. It would not prove there was discrimination, but it would indicate something worthy of further investigation.