Knowledge level learning and the power law: A soar model of skill acquisition in scheduling

Zusammenfassung. Das hier vorgestellte Modell lernt graduell, Planungsaufgaben aus der Klasse der Maschinenbelegungsprobleme (job-shop-scheduling problems) zu lösen. Mit Hilfe des Chunking-Mechanismus von Soar wird episodisches Wissen über die Belegungsreihenfolge von Aufträgen auf Maschinen memoriert. Bei der Entwicklung des Modells wurden zahlreiche qualitative (z. B. Transfereffekte) und quantitative Befunde (z. B. Bearbeitungszeiten) aus einer früheren empirischen Untersuchung berücksichtigt. In einer Validierungsstudie wurden dieselben Aufgaben von 14 Probanden und dem Modell bearbeitet. Die Passung von Simulationsdaten und empirischen Ergebnissen fiel insgesamt gut aus. Allerdings löst das Modell die Aufgaben schneller und zeigt auch einen etwas besseren Lernverlauf als die Probanden. Das Modell liefert eine Erklärung für das Rauschen, das typischerweise bei Bearbeitungszeiten zu beobachten ist: es handelt sich um erworbenes Wissen, das mehr oder weniger gut und auch unterschiedlich häufig auf neue Situationen übertragen wird. Der Lernverlauf der Probanden entspricht nur für aggregierte Daten einer Potenzfunktion (power law). Der vorgestellte Mechanismus zeigt, wie ein symbolisches Modell der Informationsverarbeitung graduelle Verhaltensänderungen generiert und wie der offensichtliche Erwerb allgemeiner Prozeduren ohne explizites Lernen von deklarativen Regeln erfolgen kann. Es wird nahegelegt, daß es sich hier um die Modellierung einer Form impliziten Lernens handelt. Summary. The model presented here gradually learns how to perform a job-shop scheduling task. It uses Soar's chunking mechanism to acquire episodic memories about the order to schedule jobs. The model was based on many qualitative (e.g., transfer effects) and quantitative (e.g., solution time) regularities found in previously collected data. The model was tested with new data where scheduling tasks were given to the model and to 14 subjects. The model generally fit these data with the restrictions that the model performs the task (in simulated time) faster than the subjects, and its performance improves somewhat more quickly than the subjects' performance. The model provides an explanation of the noise typically found in problem solving times - it is the result of learning actual pieces of knowledge that transfer more or less to new situations but rarely by an average amount. Only when the data are averaged (i.e., over subjects) does the smooth power law appear. This mechanism demonstrates how symbolic models can exhibit a gradual change in behavior and how the apparent acquisition of general procedures can be performed without resorting to explicit declarative rule generation. We suggest that this may represent a type of implicit learning.     

The puzzle of language evolution

Linguistics must again concentrate on the evolutionary nature of language, so that language models are more realistic with respect to human natural languages and have a greater explanatory force. Multi-agent systems are proposed as a possible route to develop such evolutionary models and an example is given of a concrete experiment in the origins and evolution of word-meaning based on a multi-agent approach.     

The Development of Person–Vocation Fit: A Longitudinal Study Among Young Employees

This two-phase panel study examines the development of the congruence between vocational interests and perceived skill requirements. Participants were 492 Dutch men and women between 18 and 26 years old, with a paid job in both phases. Three hypotheses inspired by the theory of work adjustment (Dawis and Lofquist 1984) and congruence theory (Holland 1992) were tested, using a composite index of fit proposed by Cronbach and Gleser (1953). The first hypothesis proposing that participants experiencing incongruence between their vocational interests and their perceived skill requirements are dissatisfied with their job was supported. The hypothesis that incongruence has a positive relationship with job change and a negative relationship with tenure was not confirmed. The expectation that the congruence between vocational interests and perceived skill requirements increases over time was confirmed. Furthermore, exploring determinants of change in vocational interests and perceived skill requirements, it was found that change in these domains was predicted by different variables, educational level being the only common factor. It is concluded that this study supports the longitudinal propositions of prevailing work-related person-environment fit theories.     

The Burden of Dementia: A Medical and Research Perspective

Alzheimer's disease remains the most common form of dementia. Dementia symptoms vary depending on individual personality, life experience, and social and cultural influences. As dementia progresses, involvement of multi-disciplinary health care professionals is needed to manage the disease. Alzheimer research is progressing rapidly. While 5% of all Alzheimer's disease may be genetically determined, the majority is not. Susceptibility genes can reveal the risk of contracting Alzheimer's disease. Early life risk factors such as education, nutrition, and vascular disease may increase the likelihood of dementia in later life. In the United States, two acetylcholinesterase inhibitors have been approved as cognitive enhancers. Possible prevention and symptomatic treatment interventions have focused on estrogen replacement therapy, antioxidants, and anti-inflammatory medications. Research advances have improved the clinical management of dementia. Ethical implications to the patient, family, and society are multiple and remain challenging.     

Authority,Psychotherapy and the Authority of the Therapist in the Religious Haredi Community

This article considers the meaning and significance of authority, and its relevance to the transference process, within the framework of psychotherapy in the orthodox Jewish (Haredi) community in Israel. In this community, deeply-rooted habits of obedience to the commandments of the Torah and the authority of the Rabbi are integral to maintaining an orthodox way of life. Clinical vignettes with Haredi patients are presented to illustrate the complexities that arise when both patient and therapist belong to the orthodox community, and highlight the authority-related issues that are central to the therapy. This combination of factors requires a sensitive and finely-tuned approach which will enable the therapist to maintain the treatment framework while still accommodating the orthodox way of life.