Logical consequence: A defense of Tarski

In his classic 1936 essay “On the Concept of Logical Consequence”, Alfred Tarski used the notion of satisfaction to give a semantic characterization of the logical properties. Tarski is generally credited with introducing the model-theoretic characterization of the logical properties familiar to us today. However, in his book, The Concept of Logical Consequence, Etchemendy argues that Tarski's account is inadequate for quite a number of reasons, and is actually incompatible with the standard model-theoretic account. Many of his criticisms are meant to apply to the model-theoretic account as well. In this paper, I discuss the following four critical charges that Etchemendy makes against Tarski and his account of the logical properties:

1. Tarski's account of logical consequence diverges from the standard model-theoretic account at points where the latter account gets it right.
2. Tarski's account cannot be brought into line with the model-theoretic account, because the two are fundamentally incompatible.
3. There are simple counterexamples (enumerated by Etchemendy) which show that Tarski's account is wrong.
4. Tarski committed a modal fallacy when arguing that his account captures our pre-theoretical concept of logical consequence, and so obscured an essential weakness of the account.
5. Tarski's account depends on there being a distinction between the “logical terms” and the “non-logical terms” of a language, but (according to Etchemendy) there are very simple (even first-order) languages for which no such distinction can be made. Etchemendy's critique raises historical and philosophical questions about important foundational work. However, Etchemendy is mistaken about each of these central criticisms. In the course of justifying that claim, I give a sustained explication and defense of Tarski's account. Moreover, since I will argue that Tarski's account and the model-theoretic account really do come to the same thing, my subsequent defense of Tarski's account against Etchemendy's other attacks doubles as a defense against criticisms that would apply equally to the familiar model-theoretic account of the logical properties.

     

An investigation of the validity of the SPSI and SPSI-R in differentiating high-suicidal from depressed,low-suicidal college students

The present study examined the validity of the Social Problem-Solving Inventory (SPSI) and SPSI—Revised in differentiating 65 high-suicidal from 63 depressed, low-suicidal college students. Results from multivariate analyses indicated overall differences in problem-solving between these two groups as measured by the SPSI but not by the SPSI-R. Further examination of these differences revealed the high-suicidal group was different in problem-solving orientation, rather than problem-solving skills, compared to the depressed, low-suicidal group. However, when depression was statistically controlled in hierarchical regression analyses, none of the problem-solving measures predicted group membership. The superiority of the SPSI to the SPSI-R in differentiating these two groups appears to be accounted for by the elimination of 28 items in the revised version, many of which measure orientation to problem-solving. Also explored was the possibility that objective measures of problem-solving provide a better prediction of adjustment than do self-report measures.     

The development of the Telic Dominance Scale

The development of a 42-item measure of a number of personality features derived from the theory of psychological reversals is reported. These personality features are (a) the extent to which a person is serious-minded, (b) the extent to which a person plans ahead and organizes himself in the pursuit of goals, and (c) the extent to which a person seeks to avoid arousal. These features together are seen to constitute a personality trait which is described as telic dominance. Data concerning the test-retest reliability, criterion-related and construct validity of the Telic Dominance Scale are presented, together with the scale and scoring key.     

Time-series analysis of long-term cardiovascular response

The purpose of this study was to illustrate the use of time-series analysis with long-term cardiovascular responding. Analyses of two successive 1000-minute mean blood pressure and heart-rate series in five chronically instrumented dogs showed that the autocorrelation function of the original series appeared highly nonstationary and that differencing the data produced a simple autocorrelation pattern which could be successfully modeled with stepwise autoregression. Evidence for reliable individual differences as well as change over sessions is presented and discussed.     

Race and climate as influences on anxiety

Lynn (1971) argues that Nordic race and cool climates independently predispose people to low levels of chronic anxiety. He also associates high economic growth and high anxiety. Random population samples of the cities of Sydney (Australia), Munich (W. Germany) and Bombay (India) received the short form of Eysenck's MPI N scale and the means obtained were compared with one another and with the scale's English norms. Two studies of the Parsee communities in Bombay and Sydney were also carried out. Except for the Bombay Parsees, all translations of the scale (into Gujurati, Hindi, Marathi and German) appeared to have been successful as evidenced by satisfactory levels of α. There were no significant differences between the Indian, Australian, English and German means—thus upsetting Lynn's theories. Sydney Parsees were however significantly less anxious than Bombay Parsees—thus suggesting that Parsee immigration to Australia is a viable solution to the threatened position in which Parsees find themselves in India.     

Control of CRT intensity via Apple II software

An inexpensive, easy-to-build device for the Apple II microprocessor is described. The modification permits software control of four levels of relative screen intensity (contrast) settings for any video monitor. The relationship of the technology to choice reaction time and perception research is briefly indicated. Principles governing operation of the modification are also discussed. Finally, a set of step-by-step instructions for building the device is provided.     

Integration of information from multiple element displays

This experiment examined the processing of information from multiple element visual displays, using techniques derived from the theory of signal detectability. The method allows one to specify how observers integrate information from individual elements of a display. The experiment tested numerical and graphical displays having different display sizes, durations, and arrangements of elements. Observer performance increased with the number, m, of display elements, but at less than the ideal √m rate. Observer performance was consistent with a model of information integration constrained by internal noise. Linear arrays of elements resulted in better performance than did square arrays. Graphically coded elements resulted in better performance than did numerical elements. Observer decision weighting of element information from graphical displays was approximately uniform across spatial position, but the weighting of information from numerical displays was concentrated on elements near the fixation point.     

The cognitive interview: Its origins,empirical support,evaluation and practical implications

This paper provides a background to current research on the cognitive interview (CI), which is a set of cognitive retrieval techniques designed to facilitate memory search (for example, via reinstatement of contextual cues). One of the principal aims of this research is to identify and develop techniques which police investigators can themselves use. A series of studies were conducted at the University of California, Los Angeles, using police officers as interviewers and students, non-students and children as witnesses to realistic crimes. In all studies the CI elicited significantly more correct information with no apparent increase in errors or confabulations. The CI has been tested in a field study involving police officers in Florida. This paper will critically review this research, as well as more recent unpublished work including CI studies conducted in Germany and the UK. Some important modifications of the original CI procedure are described, and there is a theoretical discussion and explanation of the various components of the CI procedure. Finally, we will consider applications of the CI in clinical and organizational settings.     

Teaching minority high school students to recruit helpers to attain personal and educational goals

Recruiting help from mentors and other potential helpers is a promising strategy for helping disadvantaged and minority youths meet their personal and educational goals. Three African-American high school seniors participated in a project designed to evaluate the effectiveness of training procedures that would allow them to ask for help in attaining educational and other personal goals. A behavioral training procedure that included instructional materials, role-play practice, praise, and feedback was used. Targeted skills included goal setting and 30 responses involved in the process of meeting with a potential helper. Role-play situations were used to evaluate participants' help-recruiting skills before and after training. Participants increased their help-recruiting skills from an average of 38% during baseline, to an average of 75% after training. Self-reported measures of goal attainment suggested that the students benefited from the training. Implications for mentoring programs designed to increase minority students' opportunities to reach educational goals were discussed.