Measuring the ratio of true-positive to false-positive judgements made by child and family social workers in England: A case vignette study

Social workers routinely make judgements and decisions as part of their everyday practice. The nature and quality of these can have a significant and long-lasting impact on the children and families concerned. In this paper, we present an analysis of more than 20 000 judgements (n = 21 193) made by social workers (n = 586) in relation to case vignettes, based on a series of anonymized referrals (n = 12) to social services in England. We do so to ascertain how accurately the social workers were able to predict subsequent actions, events and outcomes, and to calculate the ratio of true positives to false positives at various decision thresholds. We find that the social workers' predictions were more accurate than chance in relation to all but one of the referrals, albeit at the cost of a high rate of false positive errors. We consider these findings in relation to what appears to be a general lowering of the threshold for child protection interventions in England in recent years and in relation to who suffers the injustice of false positive errors in child and family social work.