Partial monotonicity and a new version of the Ramsey test

We introduce two new belief revision axioms: partial monotonicity and consequence correctness. We show that partial monotonicity is consistent with but independent of the full set of axioms for a Gärdenfors belief revision sytem. In contrast to the Gärdenfors inconsistency results for certain monotonicity principles, we use partial monotonicity to inform a consistent formalization of the Ramsey test within a belief revision system extended by a conditional operator. We take this to be a technical dissolution of the well-known Gärdenfors dilemma.In addition, we present the consequential correctness axiom as a new measure of minimal revision in terms of the deductive core of a proposition whose support we wish to excise. We survey several syntactic and semantic belief revision systems and evaluate them according to both the Gärdenfors axioms and our new axioms. Furthermore, our algebraic characterization of semantic revision systems provides a useful technical device for analysis and comparison, which we illustrate with several new proofs.Finally, we have a new inconsistency result, which is dual to the Gärdenfors inconsistency results. Any elementary belief revision system that is consequentially correct must violate the Gärdenfors axiom of strong boundedness (K^*8), which we characterize as yet another monotonicity condition.This work was supported by the McDonnell Douglas Independent Research and Development program.     

Relevance and digressions in argumentative discussion: A pragmatic approach

Digressions in argumentative discussion are a kind of failure of relevance. Examination of what actual cases look like reveals several properties of argumentative relevance: (1) The informational relevance of propositions to the truth value of a conclusion should be distinguished from the pragmatic relevance of argumentative acts to the task of resolving a disagreement. (2) Pragmatic irrelevance is a collaborative phenomenon. It does not just short-circuit reasoning; it encourages a failure to take up the demands of an argumentative task. (3) Pragmatic irrelevance can occur not simply by the absence of a connection between what is said and some standpoint in dispute, but also by the presence of a connection between what is said and a competing use of the information. (4) Pragmatic relevance must be accomplished through communicative action.     

Idiothetic inquiry and the toil of Sisyphus

In response to the article by Lamiell and Trierweiler (this issue), we examine the stated epistemological origins of idiothetic proposals for theory and research in personality We argue that the justification for those proposals as advanced by Lamiell and his colleagues is wholely insufficient in view of prior research on the consistency of behavior This assertion together with our identification of problems in scaling personality and personality consistencies lead us to conclude that the pursuit of the idiothetic method is both unwarranted and ineffectual     

Lifespan normative data (18–89 years) for Raven's Advanced Progressive Matrices Set I

Raven's Advanced Progressive Matrices (APM) Set I is a validated and brief test of fluid intelligence, ideal for use in busy clinical settings. However, there is a dearth of normative data allowing an accurate interpretation of APM scores. To address this, we present normative data from across the adult lifespan (18–89 years) for the APM Set I. Data are presented in five age cohorts (total N = 352), including two older adult cohorts (65–79 years and 80–89 years), which allows age-standardized assessment. We also present data from a validated measure of premorbid intellectual ability, which was absent from previous standardizations of longer forms of the APM. In line with previous findings, a striking age-related decline was noted, beginning relatively early in adulthood and most marked amongst lower-scoring individuals. Older adults did not demonstrate difficulty with specific test items or make an increased proportion of specific errors. Sex was not a significant predictor of performance. The data set is of particular use in the neuropsychological assessment of older adults, given the known susceptibility of fluid intelligence to both the effects of normal ageing and acquired brain injury in older age. The results are discussed in light of theories of neurological ageing.