Remarks on the development of computability

The purpose of this article is to examine aspects of the development of the concept and theory of computability through the theory of recursive functions. Following a brief introduction, Section 2 is devoted to the presuppositions of computability. It focuses on certain concepts, beliefs and theorems necessary for a general property of computability to be formulated and developed into a mathematical theory. The following two sections concern situations in which the presuppositions were realized and the theory of computability was developed. It is suggested in Section 3 that a central item was the problem of generalizing Gödel's incompleteness theorem. It is shown that this involved both the characterization of recursiveness and the attempt to clarify and formulate the notion of an effective process as it relates to the syntax of deductive systems. Section 4 concerns the decision problems which grew from the Hilbert program. Section 5 is devoted to the development of an informal' technique in the theory of computability often called ‘argument by Church's thesis’.     

A Debate About Anderson's Logic

This article is about the history of logic in Australia. Douglas Gasking (1911–1994) undertook to translate the logical terminology of John Anderson (1893–1962) into that of Ludwig Wittgenstein's (1921) Tractatus. At the time Gilbert Ryle (1900–1976), and more recently David Armstrong, recommended the result to students; but it is reasonable to have misgivings about Gasking as a guide to either Anderson or Wittgenstein. The historical interest of the debate Gasking initiated is that it yielded surprisingly little information about Anderson's traditional (syllogistic or Aristotelian) logic and its relation to classical (first-order predicate or Russellian) logic, the ostensible topic; but the materials now exist to interpret Anderson's logic in classical logic, possibly as an algebra of classes. This would be of little interest to contemporary logicians, but it might shed some light on Anderson's philosophy.     

Valedictory

Contingentism, generally contrasted with law necessitarianism, is the view that the laws of nature are contingent. It is often coupled with the claim that their contingency is knowable a priori. This paper considers Bird's [2001 Bird, Alexander 2001. Necessarily, Salt Dissolves In Water, Analysis 61/4: 267–74.[Crossref], [Web of Science ®] , [Google Scholar], 2002 Bird, Alexander 2002. On Whether Some Laws Are Necessary, Analysis 62/3: 257–70.[Crossref], [Web of Science ®] , [Google Scholar], 2005 Bird, Alexander 2005. Unexpected A Posteriori Necessary Laws of Nature, Australasian Journal of Philosophy 83/4: 533–48.[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar], 2007 Bird, Alexander 2007. Nature's Metaphysics: Laws and Properties, Oxford: Clarendon Press.[Crossref] , [Google Scholar]] arguments for the thesis that, necessarily, salt dissolves in water; and it defends his view against Beebee's [2001] and Psillos's [2002 Psillos, Stathis 2002. Salt Does Dissolve In Water, But Not Necessarily, Analysis 62/3: 255–7.[Crossref], [Web of Science ®] , [Google Scholar]] contingentist objections. A new contingentist objection is offered and several reasons for scepticism about its success are raised. It is concluded that certain higher-level laws describing the behaviours of molecular compounds may be necessary due to their dependence on underlying physical laws, and that the modal status of laws of nature cannot be determined a priori, as the structural features of the substances and properties they govern must first be investigated.     

Personal goals as predictors of intended classroom goals: Comparing elementary and secondary school pre‐service teachers

Background and Aims. The literature documents fewer classroom mastery goal structures in secondary school compared to elementary. However, little is known about how personal achievement goals may influence classroom goal structures. This is especially true at the level of pre‐service teachers. Our objective was to investigate if pre‐service teachers’ personal goals predicted their intended classroom goal structures. Sample. Participants were 125 elementary and 175 secondary school pre‐service teachers from two Western Canadian universities. Method. Structural equation modelling was used to examine if the structural relationships and latent means of personal and intended classroom goal structures differed for elementary and secondary school pre‐service teachers. Results. The results revealed that personal goals predicted the goal structures that pre‐service teachers intended to establish; however, the relationships and means differed between elementary and secondary school pre‐service teachers. Specifically, personal mastery‐approach goals positively predicted classroom mastery goals much more strongly at the elementary than the secondary level. Furthermore, elementary pre‐service teachers had significantly higher latent mean scores on personal mastery‐approach goals than their secondary counterparts. Conclusions. It seems possible that the currently documented differences between classroom goal structures noted for elementary compared to secondary school may be based on the personal goals endorsed as pre‐service teachers. The results are further discussed in terms of alignment with research on practising teachers’ personal and classroom goals and implications for teacher education.     

Cue competition effects in the planarian

The learning abilities of planarian worms (Dugesia tigrina) were assessed by using a number of Pavlovian conditioning paradigms. Experiment 1 showed that planaria were susceptible to basic conditioning in that they readily developed a conditioned response to a change in ambient luminance when it was consistently paired with an electric shock over a number of trials. In Experiment 2, the change in luminance was presented in a compound with a vibration stimulus during conditioning. Subsequent tests revealed poor conditioning of the elements compared with control groups in which the animals were conditioned in the presence of the elements alone, an instance of overshadowing. In Experiment 3, pre-training of one of the elements before compound conditioning resulted in blocking of learning about the other element. These results add to other studies that have reported cue competition effects in animal species belonging to different phyla (chordate, mollusk, arthropod), suggesting that learning in these phyla could be ruled by similar principles. The results are discussed adopting an evolutionary-comparative approach.     

Awareness of Genetic Counseling and Perceptions of its Purpose: A Survey of the Canadian Public

Genetic counseling can result in better outcomes when clients understand what to expect, and at least theoretically, at some point in their lifespan, anyone could be referred for or benefit from genetic counseling. Thus, in order to identify (and ultimately address) issues around awareness of genetic counseling and perceptions of its purpose, we surveyed the Canadian general population. We acquired 1,000 telephone numbers corresponding to a demographically representative sample of Canada from Survey Sampling International, and invited individuals to participate in a telephone-based survey. We administered a purpose-designed survey (in either French or English) comprising questions regarding: demographics, whether or not the individual had heard of genetic counseling, and 15 Likert scale-rated (strongly disagree—strongly agree) items about the possible purposes of genetic counseling. Responses to these 15 items were used to generate a total “knowledge score”. Of the 1,000 numbers, n?=?372 could not be reached, and the survey was successfully administered to n?=?188 individuals (response rate 30 %). Most respondents (n?=?129, 69 %) had not heard of genetic counseling, and substantial proportions thought that genetic counseling aims to prevent genetic diseases and abnormalities, help couples have children with desirable characteristics, and help people to understand their ancestry. These data could be used to inform the strategy for development of future awareness efforts, and as a baseline from which to measure their effects.     

Effects of lifestyle and stress on the employee and organization: Implications for promoting health at work

Abstract

This research was designed to determine the extent to which employee health and performance are predicted by lifestyle and stress. Data were collected from 345 employees working in a variety of organizations in southern California. Additionally, supervisors evaluated the work performance of the participating employees whom they directly supervised, and company records of employee health care costs were obtained. Hierarchical multiple regression analyses revealed (a) that physical lifestyle (i.e., exercise pattern, eating habits, and general health practices) predicted unique variance in vitality and positive well-being; (b) that psychosocial lifestyle (i.e., social relations, intellectual activity, occupational conditions, and spiritual involvement) predicted unique variance in vitality, positive well-being, anxiety, depression, lack of self-control, and somatic complaints; (c) that employee stress predicted unique variance in vitality, positive well-being, anxiety, depression, physician visits, somatic complaints, illness absences, and supervisory ratings of job performance, absenteeism and tardiness; (d) that physical lifestyle buffered the adverse consequences of stress for anxiety, depression, physician visits, and company health care costs; and (e) that there was a Physical x Psychosocial Lifestyle interaction for anxiety, depression, and lack of self-control. However, the employee lifestyle factors were not related to supervisory ratings of performance at work. The findings have direct implications for organizational health programs and policies.     

A Brief Parenting Intervention to Enhance the Parent–Child Relationship in Hong Kong: Harmony@Home

There is a dearth of high-level evidence for brief programs designed to promote positive parent–child relationships in nonwestern cultures. We present a pilot randomized controlled trial of a four-session intervention to enhance the parenting skills that promote a positive relationship with pre-adolescent children in Hong Kong. Our intervention, Harmony@Home, utilized Cunningham’s culturally appropriate coping modeling, problem-solving approach to change parental behavior. Our objective was to evaluate the feasibility, acceptability and initial evidence of benefit of the intervention. We blindly randomized 150 Hong Kong parents of children 10–13 years of age to (a) a Harmony@Home intervention group, (b) a waitlist control group, or (c) a third active intervention which shared the control group. Immediately following the intervention, we report increases in satisfaction with the parent–child relationship, one of the targeted parenting behaviors and family harmony, for the Harmony@Home group versus control group. However, only the results from satisfaction with the parent–child relationship were significant at 3-months post intervention. Most respondents reported high levels of program satisfaction. The results provide preliminary evidence that this parenting intervention is culturally acceptable for a nonwestern general population, is feasible for implementation in a community setting and shows evidence of benefit. This intervention is concordant with public health priorities because of the global importance of the parent–child relationship as a protective factor for adolescent outcomes, the need for culturally-appropriate interventions for nonwestern populations, and design characteristics that promote dissemination.     

Reliability and Validity of the Dyadic Observed Communication Scale (DOCS)

We evaluated the reliability and validity of the Dyadic Observed Communication Scale (DOCS) coding scheme, which was developed to capture a range of communication components between parents and adolescents. Adolescents and their caregivers were recruited from mental health facilities for participation in a large, multi-site family-based HIV prevention intervention study. Seventy-one dyads were randomly selected from the larger study sample and coded using the DOCS at baseline. Preliminary validity and reliability of the DOCS was examined using various methods, such as comparing results to self-report measures and examining interrater reliability. Results suggest that the DOCS is a reliable and valid measure of observed communication among parent-adolescent dyads that captures both verbal and nonverbal communication behaviors that are typical intervention targets. The DOCS is a viable coding scheme for use by researchers and clinicians examining parent-adolescent communication. Coders can be trained to reliably capture individual and dyadic components of communication for parents and adolescents and this complex information can be obtained relatively quickly.     

A REVIEW OF THE CONTRIBUTION OF PERSONAL CONSTRUCT PSYCHOLOGY TO STAMMERING THERAPY

In the wake of Fransella's (1972) seminal application of Kellyian ideas to the understanding of stammering, the impact of personal construct psychology (PCP) upon speech and language therapists working in this area has been significant. This article reviews the literature and considers the developments in the management of stammering wrought through the application of PCP. A number of key issues relating to the meshing of traditional speech therapy methods and PCP are discussed and these are illustrated further by a specific personal clinical experience.