SCORING-RULE FEEDFORWARD AND THE ELICITATION OF SUBJECTIVE-PROBABILITY DISTRIBUTIONS

In the context of assessing subjective probability distributions, scoring rules can be used for elicitation, evaluation, and training purposes. The emphasis in the present study is on elicitation purposes and the main objective is to study the use of scoring rules for generating graphical feedforward about the consequences of a probability assessment. This notion of providing graphical feedforward about possible scores was carried through in the computerized interactive ELIcitation technique, ELI (Van Lenthe, 1993b). The effectiveness of scoring-rule feedforward was investigated in experiment A, in which 192 subjects participated. Scoring-rule feedforward, provided during the assessment process, appeared to result in a better calibration and a higher accuracy of the probability assessments. Differential effects of scoring rules were studied in experiment B, in which 304 subjects took part. Feedforward generated with different proper scoring rules (logarithmic, quadratic, spherical) yielded similar calibration and accuracy scores. A fourth condition with feedforward according an improper linear scoring rule, however, produced significantly lower scores. Finally, possible effects of the orientation (positive, negative, or both) of feedforward scores were explored, but no differences were found between conditions with mixed-score feedforward and conditions with positive-score feedforward. The ELI procedure of providing graphical scoring-rule feedforward during the elicitation process seems to be a promising method for improving the quality of probability assessments. The ELI procedure appears to be robust with respect to different types of proper scoring rules and with respect to different ranges of feedforward scores. (C) 1994 Academic Press, Inc

A blueprint of ELI: A new method for eliciting subjective probability distributions

A blueprint of a new method for eliciting uncertain knowledge about continuous quantities is presented. The direct realization of a proper scoring rule in a graphically oriented interactive computer program is one of the central features of the new elicitation methodology. Uncertain knowledge is internally represented through subjective probability distributions. However, in its interaction with assessors, the elicitation method uses a score representation. A proper scoring rule is applied to transform probability density functions into score functions. In order to study its merits, central ideas for the new method were implemented in an experimental version of the elicitation technique ELI. The results were promising and encouraged further development of the technique

Carbon-Silicon Bond Activation by [Pd(ItBu)(2)] - the Molecular Structures of [Pd(Me3Si)(ItBu)(mu-I)](2) and [Pd(CH(2)ItBu)I-2]

The reaction of Me3SiCH2I with [Pd(ItBu)(2)] (ItBu = 1,3-di-tert-butyl-imidazol-2-ylidene) results, not in simple oxidative addition, but in carbon-silicon bond activation and formation of [Pd(Me3Si)(ItBu)(mu-I)](2) (2) and [Pd(CH(2)ItBu)I-2] (3). The zwitterionic nature of the latter has been confirmed by DFT studies, and a possible mechanism for the formation of these two unexpected products is presented. Complex 2 has also been synthesised independently by the direct oxidative addition of Me3SiI to [Pd(ItBu)(2)]