Minimum Risk Invariant Estimators of a Continuous Cumulative Distribution Function

The problem of nonparametric minimum risk invariant estimation has engaged a good deal of attention in the literature and minimum risk invariant estimators (MRIE's) have been constructed for some special statistical models. We present a new and simple method of obtaining the MRIE's of a continuous cumulative distribution function (cdf) under a general invariant loss function. All the MRIE's, which are known from the literature, can be constructed by the method presented in the article, in particular, under the weighted quadratic, LINEX and entropy loss functions. This method enables also to construct the MRIE's in nonparametric statistical models which have not been considered until now. In particular, considering a family of nonparametric precautionary loss functions, a new class of MRIE's of the cdf has been found. We also give some general remarks on obtaining the MRIE's and a review concerning minimaxity and admissibility of MRIE's.     

Bayes sequential estimation for a time-transformed exponential model

A problem of Bayesian sequential estimating an unknown parameter of a time-transformed exponential model is considered. It is supposed that the loss associated with the error of estimation is weighted squared or precautionary and the cost of observing the process is a function of time and the number of observations. Bayes sequential procedures for estimating the unknown parameter are presented.     

Educating for social work in Poland—challenges of the transformation period

This article discusses the changing approach to social welfare staff education against a background of political and social transformation in Poland: new social processes, growth of social problems—especially crime and unemployment, a widening poverty sphere, but at the same time new possibilities created by the development of democratic structures, requiring new qualifications. The change in professional profile of social workers and an updated curriculum were natural consequences of that demand. Both internal reforms as well as an increase in international contacts have had a great impact on the curriculum, making it modern in regard to its content and the approach to the process of education. Important virtues of the curriculum are: due consideration for the international context of the material presented and teaching goals defined in such way that they meet the transformation period requirements without introducing only provisional solutions. Professional improvement training and post-diploma courses have also been mentioned as an important factor of successful welfare sector operations. This kind of education equips welfare staff with necessary qualifications and prevents burnout syndrome. The article briefly discusses new conditions for social education development and identifies the remaining stumbling blocks.