Truncated Sequential Change-point Detection based on Renewal Counting Processes

The typical approach in change-point theory is to perform the statistical analysis based on a sample of fixed size. Alternatively, one observes some random phenomenon sequentially and takes action as soon as one observes some statistically significant deviation from the "normal" behaviour. Based on the, perhaps, more realistic situation that the process can only be partially observed, we consider the counting process related to the original process observed at equidistant time points, after which action is taken or not depending on the number of observations between those time points. In order for the procedure to stop also when everything is in order, we introduce a fixed time horizon n at which we stop declaring "no change" if the observed data did not suggest any action until then. We propose some stopping rules and consider their asymptotics under the null hypothesis as well as under alternatives. The main basis for the proofs are strong invariance principles for renewal processes and extreme value asymptotics for Gaussian processes.     

Social Work Teachers and Social Work Practice

Summary A survey was undertaken to discover the extent to which thosesocial work teachers who teach social work methods, continueto practise after they become educators. The results suggestthat not more than 25% do so, and many of these on only a tokenbasis. Most respondents however regarded such practice as animportant aide to the teaching of social work methods, althoughsome consider consultancy roles to be equally relevant. In nocases was such practice linked with research, and only exceptionallydid employers allow time explicitly for it. We outline fourdifferent bases on which teachers might practise, all of whichwere suggested by respondents, many of whom added personal notesto the questionnaire, indicating the extent to which this subjectis a matter of wide interest and concern