Although commercial and household wastes are compositionally similar, common UK practice is for separate collections. This paper uses vehicle routeing and scheduling software to predict the benefits of allowing household and commercial waste to be collected together by a common vehicle fleet. This was compared in a case study where collections were made from over 25,000 households on an alterna...

The asymptotic standard errors of the IRT equating coefficients given by the mean/sigma, mean/mean and mean/geometric mean methods are derived when the two-parameter logistic model holds and item parameters are obtained by the marginal maximum likelihood estimation. The case of two nonequivalent examinee-groups and the case of single group are considered. The numerical examples show that the me...

Item parameter calibration is important for tests based on item response theory, because the scoring, equating, bias analysis of the test, and item selection in adaptive tests are all based on the item parameters. As a test is continuously administered, item calibration needs to be conducted for new items at intervals to replace overexposed, obsolete, or flawed items in the item bank. Although ...

iii Brennan Equity The notion of equity in equating was introduced by Lord (1980. pp. 195ff). The basic idea is that for any true score on Form Y, the distribution of observed scores on Form Y should be the same as the distribution of converted scores on Form X (see Kolen & Brennan, 2004. pp. 10–11). If this goal is achieved, Lord argued, then it should be a matter of indifference to each and e...