The consistency of the constraint with the evolution equations for spatially inhomogeneous and irrotational silent (SIIS) models of Petrov type I, demands that the former are preserved along the timelike congruence represented by the velocity of the dust fluid, leading to new non-trivial constraints. This fact has been used to conjecture that the resulting models correspond to the spatially hom...

At one time, the Jainas in India and Greeks abroad held that unity was not a number. This paper provides an insight for first time into thoughts offered by as to why number them.

Decades of research in causal and contingency learning show that people's estimations of the degree of contingency between two events are easily biased by the relative probabilities of those two events. If two events co-occur frequently, then people tend to overestimate the strength of the contingency between them. Traditionally, these biases have been explained in terms of relatively simple si...

Motivation plays a key role in learning and teaching, in particular in technology enhanced learning environments. According to motivational theories, proper contingency design is an important prerequisite to motivate learners. In this paper, we demonstrate how confidence levels in an adaptive educational system can be raised using a contingency design technique. Learners that saw parts of a com...

Subjects made judgments concerning the strength and direction of the contingency between two dichotomous variables in a situation in which no contingency actually existed. The judgments exhibited a significant primacy effect. The effects of warning and not warning the subjects that they would be required to recall the frequencies of observed event co-occurrences implied that this primacy effect...