When modeling student learning, tutors that use the Knowledge Tracing framework often assume that all students have the same set of model parameters. We find that when fitting parameters to individual students, there is significant variation among the individual’s parameters. We examine if this variation is important in terms of instructional decisions by computing the difference in the expecte...

The joint asymptotic distributions of the marginal quantiles and quantile functions in samples from a p-variate population are derived. Of particular interest is the joint asymptotic distribution of the marginal sample medians, on the basis of which tests of significance for population medians are developed. Methods of estimating unknown nuisance parameters are discussed. The approach is comple...

The m-testing of model specification pioneered by Newey (1985) and Tauchen (1985) and extended by White (1987) offers a general framework that unifies many specification tests in the literature. Within the m-testing framework, we consider how to test the hypothesis that a model is correctly specified in each of many groups in the population under study, where each of the groups offers only a fe...

the life history of an acarid mite, tyrophagus putrescentiae (schrank), on fusarium graminearum clade was investigated at 25 â± 1â°c, 60 â± 5% rh and a photoperiod of 16: 8 (l: d) h. incubation period for egg hatch, larval and nymphal periods and adult longevity were 2.22 â± 0.06, 3.46 â± 0.12, 4.84 â± 0.16 and 10.05 â± 0.9 days, respectively. the average life span of males and females were 22....

long term monitoring programme on brine shrimp ( artemia sp.) is being carried out by the environment agency, abu dhabi, united arab emirates (ead) with the prime purpose of understanding the population dynamics, ecology and habitat requirements of artemia at al wathba lake, situated within al wathba wetland reserve, which is an artificial wetland near abu dhabi city. the present study, being a...

during this study from december 2009 to november 2011, 363deep flounder fish were caught and their weight and length were measured. the caught fish included 18 males, 200 females and 155 immature fishes. the mean, maximum and minimum total lengths were 264 ± 57 (mean ± sd), 415 mm and 115 mm respectively. the mean, maximum, and minimum total weights for this species were 238 ± 150 g, 827 g and ...

the life table parameters of schizaphis graminum (rondani) (hemiptera: aphididae) on four commercial cultivars of wheat (kohdasht, pastor, tajan and zagros) were determined in laboratory conditions. fertility life table were constructed using age-specific survivorship (lx) and age-specific fecundity (mx) and subsequently analyzed using jackknife method and anova. there were significant differen...

The expected numbers of different categories of polymorphic sites are derived for two related models of population history the isolation model, in which an ancestral population splits into two descendents, and the size-change model, in which a single population undergoes an instantaneous change in size. For the isolation model, the observed numbers of shared, fixed, and exclusive polymorphic si...