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.     

Psychological Distress and Symptoms of Posttraumatic Stress Disorder in Jewish Adolescents Following a Brief Exposure to Concentration Camps

We investigated the psychological impact of an organized visit to Polish concentration camps on Jewish-American adolescents. Eighty-seven adolescents who participated in a B'nai B'rith memorial visit to concentration camps in Poland completed measures of general psychological adjustment and posttraumatic stress disorder (PTSD) at four time-points: pretest, posttest, 6-month follow-up and 12-month follow-up. Measures included the SCL-90-R, the Mississippi Scale for PTSD, and the Impact of Events Scale (IES) for PTSD. On the SCL-90-R, changes in somatization, interpersonal sensitivity, obsessive-compulsive tendencies, depression, anxiety, and phobic anxiety were observed over time, with peak symptom scores at posttest and 6-month follow-up. Scores on the Mississippi Scale for PTSD and the IES Intrusion subscale also increased at 6-months. Predictors of PTSD symptoms on the Mississippi Scale included previous psychiatric treatment and SCL-90-R symptoms of paranoia, depression, and psychosis. Elevated psychotic symptoms on the SCL-90-R predicted PTSD symptoms on the IES. Jewish adolescents with preexisting symptoms of generalized distress or psychoticism appeared at increased risk for PTSD symptoms following exposure to Holocaust stimuli. This study contributes a prospective, multi-measure assessment of trauma reactions in adolescents.     

Case Report—Loyalty, Legacy, and Ledger: Contextual Therapy in a Patient with a Family History of Ovarian Cancer

A client's emotional experiences and reactions to those experiences are influenced by his/her family of origin and direct or indirect interactions with various family members. Contextual therapists propose that a client's satisfaction with a relationship depends on the equity of his/her emotional interactions with family members. When relationships are inequitable, trust between individuals disintegrates. In order to reestablish trust in a relationship, a balance of interests must be restored. If not, imbalances may be passed down to future generations. A case of a woman with a family history of ovarian cancer is reviewed with the principles of contextual therapy in mind. In her family, several legacies have resulted in unbalanced relationships between family members that lead to difficulty in establishing trust within the genetic counseling session.     

Parsing silhouettes: The short-cut rule

Many researchers have proposed that, for the purpose of recognition, human vision parses shapes into component parts. Precisely how is not yet known. The minima rule for silhouettes (Hoffman & Richards, 1984) defines boundary points at which to parse but does not tell how to use these points to cut silhouettes and, therefore, does not tell what the parts are. In this paper, we propose the short-cut rule, which states that, other things being equal, human vision prefers to use the shortest possible cuts to parse silhouettes. We motivate this rule, and the well-known Petter’s rule for modal completion, by the principle of transversality. We present five psychophysical experiments that test the short-cut rule, show that it successfully predicts part cuts that connect boundary points given by the minima rule, and show that it can also create new boundary points.     

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.