Representation and explanation in psychometric modeling

This chapter presents a commentary on representation and explanation in psychometric modelling, as discussed in the previous chapter. It explores Turkheimer’s arguments that standard psychometric techniques involve assumptions, conventions, and definitions that introduce an arbitrary component into the models used.

A Generic Tool Path Generation Methodology for Incremental Forming

This paper presents a generic methodology for tool path generation for an arbitrary component that can be formed by single point incremental forming (SPIF) to obtain required geometrical accuracy. Adaptive slicing concepts used in layered manufacturing have been modified and used for generating tool path for SPIF. Experiments and FEA have been carried out to study the effectiveness of the proposed methodology. Results indicate that the proposed methodology enhances the accuracy achievable in SPIF.

New possibilities of applications of the Barker quasi-lattice theory. Prediction of gE and hE of binary systems whose one component is formed by n-alkanes

For binary systems of the type an arbitrary component + n-alkane we derived relations, on the basis of the Barker theory and on the basis of the group contribution concept, for predicting gE and hE from one system to another when the n-alkane length is changed. To carry out the prediction it is not necessary to evaluate any adjustable parameters. The developed method was tested using a large number of different systems covering alcohols, amines, ketones, esters, chlorinated derivatives of hydrocarbons, aromatic hydrocarbons and n-alkanes from n-pentane to n-hexadecane. The results of predictions are in very good agreement with experimental data in the cases, when the n-alkanes involved are not longer than n-decane. Systematic regular deviations in hE in the cases, when at least one of n-alkanes involved is longer, can be explained by the presence of orientation effects in the pure longer n-alkanes. The correction suggested by us for these effects improves considerably results obtained. The developed method appears to be suitable for the systematic prediction of excess quantities of systems of the given type and represents an effective test of the Barker theory.

Homing in: on arguing for remote representations

Linguistic analysis possesses both an ‘arbitrary’ and a ‘natural’ component – on the one hand, methodological principles and various means of organizing and handling data; on the other, empirical studies aimed at exposing linguistic universals through the detailed analysis of specific languages, cross-linguistic comparison, phonetic studies, psycholinguistic experiments, observation of language acquisition, and other sources of pertinent data. In practice, the arbitrary and natural components are intertwined, and each makes use of methods and results from outside linguistics in a narrow sense: the arbitrary component contains many principles and methods which are not peculiar to linguistics at all, but are rather the common property of scientific investigation, while the natural component refers ultimately to aspects of mental and social organization and physical properties of the vocal tract, many of which are independent of speci-fically linguistic behaviours and abilities.

The Temporal Pattern of Behaviour in Isolated Male Zebra Finches : Transition Analysis

A transition analysis has been carried out on the behaviour of single male zebra finches, isolated as far as possible from all varying environmental stimuli. As wide a variety of behaviour patterns as feasible was included and grouping of these was kept to a minimum. The dangers of grouping acts on functional rather than causal grounds are stressed. The method of analysis differs from most of those used previously in the following ways: 1. Data from different individuals are not massed for statistical treatment. This avoids a source of bias which makes it difficult to reach conclusions about the population as a whole. 2. Transitions between one act and itself are not considered. It is argued that models including such transitions have a strong arbitrary component and are predisposed to demonstrate merely that certain acts occur in bouts. A method is employed for calculating the expected frequencies of transitions which does not appear to have been used before in this field. It is based on a random model which excludes from consideration homogeneous transitions and any others which cannot occur because of environmental constraints. The analysis suggests that zebra finches show cycles of behaviour having active and inactive phases, with ingestion occurring mainly in the former and grooming in the latter. Song appears to be transitional between the two and to occur during periods when other tendencies are low, while stereotypes often follow such periods. Certain pairs of behaviours which occur frequently in sequence are discussed. In some cases one probably generates the peripheral state appropriate to the other and in others the pairing appears to have central causation. Triplet analysis on the massed data from all birds suggests that for most behaviours triplets of the form A-B-A are commoner than would be expected from the frequencies of the pairs A-B and B-A. It is suggested that factor analysis is not a very useful method for dealing with transition data. Detailed closer study of particular interactions, and of the temporal pattern of individual behaviours, are likely to prove more fruitful.