Models of Assessment in Social Work

Summary The provision of a social work service depends significantlyupon assessment of the social situation of clients as determinedby social workers. It is argued that the social worker's ‘understanding’of the social situation is framed within a particular way ofthinking about cause and effect. Three different models of suchthinking are used in practice. They are identified as the linearmodel, systems analysis and the management model. The originsand attributes of each model are described and related to thesocial, economic and political environments which have influencedtheir separate developments. The value base underlying eachmodel is explored. Issues relating to the present position ofsocial work are clarified.     

Sample Bias Resulting from a Requirement for Written Parental Consent

The parents of an eligible sample of 1618 students in gradesfour through twelve were contacted to obtain written permissionfor their children to complete questionnaires related to alcoholand drugs. The distributions of students across the parentalresponse categories (consent-denied, no-reply, or consent-granted)were compared on the student variables of sex, grade level,ethnic group, and reading and vocabulary test scores. The explicitconsent procedure produced a sample that was approximately halfthe size of the eligible population and overrepresented whitestudents while underrepresenting blacks and Asian Americans.There was no evidence of sample bias with respect to studentgender, and the evidence regarding bias on academically relatedmeasures was mixed.     

On the Contingent Valuation of Safety and the Safety of Contingent Valuation: Part 2 - The CV/SG "Chained" Approach

This article reports the results of a study aimed at estimating a willingness-to-pay based value of statistical life for road risks using a multi-stage approach which involves "chaining together" responses to contingent valuation and standard gamble questions.The rationale for employing a multi-stage approach is to break the wealth/risk of death trade-off down into a number of conceptually manageable steps, thereby trying to attenuate the various biases that appear to be pervasive in responses to more direct contingent valuation questions in the health and safety field.     

On the Contingent Valuation of Safety and the Safety of Contingent Valuation: Part 1-Caveat Investigator

This article reports the results of two studies aimed at testing and refining a procedure for estimating willingness-to-pay based monetary values of safety using the contingent valuation method. In spite of the fact that respondents were given the opportunity to discuss various safety issues and key concepts in focus group meetings held in advance of individual interviews, and were also given ample opportunity to revise their responses in the light of the overall pattern of these responses, the results show clear evidence of extensive and persistent insensitivity to the scale and scope of the safety improvements that were specified in the contingent valuation questions, as well as vulnerability to framing effects. This clearly casts serious doubt on the reliability and validity of willingness-to-pay based monetary values of safety estimated using conventional contingent valuation procedures.