COVARIANCES FOR FIXED INTERVAL SMOOTHED KALMAN FILTER PARAMETER ESTIMATES

Given time series data for fixed interval t= 1,2,…, M with non-autocorrelated innovations, the regression formulae for the best linear unbiased parameter estimates at each time t are given by the Kalman filter fixed interval smoothing equations. Formulae for the variance of such parameter estimates are well documented. However, formulae for covariance between these fixed interval best linear parameter estimates have previously been derived only for lag one. In this paper more general formulae for covariance between fixed interval best linear unbiased estimates at times t and t - l are derived for t= 1,2,…, M and l= 0,1,…, t - 1. Under Gaussian assumptions, these formulae are also those for the corresponding conditional covariances between the fixed interval best linear unbiased parameter estimates given the data to time M. They have application, for example, in determination via the expectation-maximisation (EM) algorithm of exact maximum likelihood parameter estimates for ARMA processes expressed in statespace form when multiple observations are available at each time point.     

Deviation from Organizational Norms Concerning the Relationship Between Status and Power: Equity vs. Self-Interest Theory

In past research on status and power, the two variables have often been confounded. Within an experimentally induced organization, status and power were separated and their effects on a series of dependent variables were examined. A three-factor design using high and low levels of power and status and norms prescribing defernce to high status or to high power was created. Differing predictions for deviation from the prescribed norms of self-interest theory and equity theory were contrasted. The data indicate that a low power, high status individual who is in an organization which rewards high power will deviate from the prescribed norms in order to increase his rewards. Status affected subjects' self-perceptions and interacted with power to affect conformity to prescribed norms and perception of partner.     

Pre- and post-planned evaluation: Which is preferable?

This paper compares the advantages and disadvantages of the “pre-planned” and “post-planned” approaches to evaluating program effectiveness. These evaluative approaches are compared along a number of dimensions which include: (a) Reliability of data and the cost of collecting it; (b) Internal validity; (c) External validity; (d) Evaluation obtrusiveness and threat; and (e) Program goal displacement and program direction. A model designed to help program managers decide when and under what conditions either of these two evaluative approaches should be employed is presented. One major theme throughout this discussion is that despite the growing interest in and use of pre-planned evaluation, the post-planned method has many advantages which often go unnoticed. This paper will help program administrators, planners and evaluators in selecting and implementing these two methods in light of their respective strengths and limitations.