Taking a test has been shown to produce enhanced retention of the retrieved information. On tests, however, students often encounter questions the answers for which they are unsure. Should they guess anyway, even if they are likely to answer incorrectly? Or are errors engrained, impairing subsequent learning of the correct answer? We sought to answer this question in 3 experiments. In Experimen...

Incorrect knowledge can be a problem for any intelligent system. Soar is a proposal for the underlying architecture that supports intelligence. It has a single representation of long-term memory and a single learning mechanism called chunking. This paper investigates the problem of recovery from incorrect knowledge in Soar. Recovery is problematic in Soar because of the simplicity of chunking: ...

Summery : This paper presents e system (PHENARETE) which understands and improves incompletely defined LISP programs, such as those written by students beginning t,o program in LISP. This system takes, as input, the program without any additional information. In order to understand the program, the system mete-evaluates it, using a library of praqmatic rules, describing the construction and cor...

example, are not represented in theDiagnostic and Statistical Manual of Mental Disorders (DSM) criteria.3 In evaluating the desirability of screening for depression in primary care, it is tempting, but in our view amistake, to reify theDSM criteria. This line of reasoning risks losing sight of a deeper reality: the criteria formajor depression arenot the thing itself, but rather an imperfect in...

Distributed systems have to deal with the following scenarios in practice: bugs in components; incorrect specifications of components and, therefore, incorrect use of components; unanticipated faults due to complex interactions or to not containing the effects of faults in lower-level components; and evolution of components. Extant fault tolerance models deal with such scenarios in only a limit...

We derive tight bounds for the maximum number of k-faces, 0 ≤ k ≤ d − 1, of the Minkowski sum, P1 ⊕ P2, of two ddimensional convex polytopes P1 and P2, as a function of the number of vertices of the polytopes. For even dimensions d ≥ 2, the maximum values are attained when P1 and P2 are cyclic d-polytopes with disjoint vertex sets. For odd dimensions d ≥ 3, the maximum values are attained when ...

Let P and Q be finite sets of points in the plane. In this note we consider the largest cardinality of a subset of the Minkowski sum S ⊆ P ⊕ Q which consist of convexly independent points. We show that, if |P | = m and |Q| = n then |S| = O(m2/3n2/3 + m + n).

A lattice (d, k)-polytope is the convex hull of a set of points in dimension d whose coordinates are integers between 0 and k. Let δ(d, k) be the largest diameter over all lattice (d, k)-polytopes. We develop a computational framework to determine δ(d, k) for small instances. We show that δ(3, 4) = 7 and δ(3, 5) = 9; that is, we verify for (d, k) = (3, 4) and (3, 5) the conjecture whereby δ(d, ...