In the early stages of design and choice of methods it is particularly important to consider anti-discriminatory practice issues and assess whether minority groups will be appropriately and sensitively considered in the evaluation. This will require consideration of the targeting and inclusion of groups within the programme, the relevance of aspects of the work to a range of groups and differential outcomes between these groups. It will also affect decisions about the sampling design within the evaluation.
The instruments to be used should be validated for all the types of respondent in the evaluation. If they are not, questions will arise about the validity of any conclusions drawn from their use. For instance, if an instrument has been validated for use with adults, how appropriate is it to use it for young offenders? There may be no alternative to using an instrument that has not been validated on the appropriate group, but where this happens the design of the evaluation should take account of this and look for differences between groups that may arise from the inappropriateness of the measure rather than different outcomes of the programme.
Many professional organisations such as the British Society of Criminology, the British Sociological Association and the European Evaluation Society have Codes of Practice to guide members undertaking research and evaluation in the field. Codes of practice for a wide range of countries are available on the web page of the European Society of Evaluation
There are four generally accepted ethical principles (Beauchamp & Childress 1994).