We revisit the empirically observed positive correlation between DIF and difficulty studied by Freedle and commonly seen in tests of verbal proficiency when comparing populations of different mean latent proficiency levels. It is shown that a positive correlation between DIF and difficulty estimates is actually an expected result (absent any true…

Cognitive load theory was introduced in the 1980s as an instructional design theory based on several uncontroversial aspects of human cognitive architecture. Our knowledge of many of the characteristics of working memory, long-term memory and the relations between them had been well-established for many decades prior to the introduction of the…

The choice of anchor tests is crucial in applications of the nonequivalent groups with anchor test design of equating. Sinharay and Holland (2006, 2007) suggested "miditests," which are anchor tests that are content-representative and have the same mean item difficulty as the total test but have a smaller spread of item difficulties.…

Enzyme kinetics is the study of enzymatic catalytic rates in biochemical reactions. This topic is commonly taught to life science students in introductory biochemistry courses during their undergraduate education. Unlike most other biochemistry topics, which focus on visual structures of biomolecules and their processes, enzyme kinetics is…

I propose an integrative theoretical framework for reading and writing acquisition, called the interactive dynamic literacy model, after reviewing theoretical models of reading and writing, and recent efforts in integrating theoretical models within reading and writing, respectively. The central idea of the interactive dynamic literacy model is…

In this short article I try to present a taxonomy of sources of difficulty, in particular complexity. I emphasize how these factors interact with each other and with individual differences and treatments, before illustrating some of these interactions and the methodological issues involved in studying them with examples from the empirical studies…

Student academic burden exists to varying degrees throughout the world. To reach a comprehensive and unbiased understanding of the roles of academic burden, this paper explores academic burden from different viewpoints and summarizes existing assessment indexes for it. Factors correlated with student academic burden are examined and detailed…

In this paper a sequence of nine, easy to manufacture optical black-box experiments with increasing levels of difficulty, and supportive frameworks for physics classes are introduced. They have been evaluated in a lower-secondary school at the end of optics lessons. A black-box is a kind of experimental task where the inner structure is not…

The greatest difficulty in reading Arabic script for nonnatives has long been considered as the absence of short vowels, however there is more to be dealt with. While the correlation of 28 Arabic consonants pose no great difficulty in deciphering the script, the six vowel phonemes voiced only by three letters even with help of some relevant…

A directly applicable latent variable modeling procedure for classical item analysis is outlined. The method allows one to point and interval estimate item difficulty, item correlations, and item-total correlations for composites consisting of categorical items. The approach is readily employed in empirical research and as a by-product permits…

The ranking of Wechsler subtests in terms of their "g" loadings is equivalent to ranking them in terms of the cognitive complexity of the tasks measured. Lower performing groups do not always fall behind higher performing groups the more complex the task. But that is the general rule, no matter whether the cause of the lower performance…

There is a long-standing debate about the principles constraining the combinatorial properties of suffixes. Hay 2002 and Hay & Plag 2004 proposed a model in which suffixes can be ordered along a hierarchy of processing complexity. We show that this model generalizes to a larger set of suffixes, and we provide independent evidence supporting the…

Mediation and moderation are two theories for refining and understanding a causal relationship. Empirical investigation of mediators and moderators requires an integrated research design rather than the data analyses driven approach often seen in the literature. This paper described the conceptual foundation, research design, data analysis, as…

A wide range of developments in science in recent years has altered our views of our world and ourselves in significant ways. These views challenge the direction of applied science and technology in many fields, including those associated with learning and performance in organizations. At the same time, they open up opportunities and…

This paper presents a bidding strategy that may be incorporated into case-intensive courses. The purpose of the bidding process is to equitably distribute credit when students are assigned cases of differing degrees of difficulty. The paper also collects data to help answer a basic research question regarding this device: Is there evidence of…