This paper presents a detailed ethnographic study of the design problems of a major national IT

system in UK child protection and welfare services. The implementation of the Integrated Children’s

System (ICS) has disrupted social work practice and engendered growing professional resistance,

prompting a fundamental review of its design. Marshall McLuhan’s concept of chiasmus is a central

feature of the analysis presented here of the tribulations of the ICS. Chiasmus refers to the tendency of

any system, when pushed too far, to produce unintended contradictory effects, and is an intrinsic

feature of the behaviour of complex, socio-technical systems. The dysfunctions of the ICS provide a

pertinent, large-scale example. The ICS constitutes an attempt, via technological means, to reorganize child welfare services in the UK. Whilst aimed at improving child safety, the ICS has had the

opposite effect of increasing the potential for error. This chiasmus has been exposed through the

multi-site ethnography reported here, which shows how rigidly designed processes, enforced by IT

systems, force social work professionals into unsafe investigative and recording practices which put

children at greater risk. The paper ends by proposing an alternative approach to design, based on

proven socio-technical precepts, emphasizing the principles of minimum critical specification, usercenteredness and local autonomy.