Teaching Bayesian reasoning in less than two hours.

The authors present and test a new method of teaching Bayesian reasoning, something about which previous teaching studies reported little success. Based on G. Gigerenzer and U. Hoffrage's (1995) ecological framework, the authors wrote a computerized tutorial program to train people to construct frequency representations (representation training) rather than to insert probabilities into Bayes's rule (rule training). Bayesian computations are simpler to perform with natural frequencies than with probabilities, and there are evolutionary masons for assuming that cognitive algorithms have been developed to deal with natural frequencies. In 2 studies, the authors compared representation training with rule training; the criteria were an immediate learning effect, transfer to new problems, and long-term temporal stability. Rule training was as good in transfer as representation training, but representation training had a higher immediate learning effect and greater temporal stability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What makes us like music? Determinants of music preference.

What are the determinants of music preference, and how strong is their relative influence? This article investigates the parameters that may influence music preference, focusing on the cognitive, emotional, and cultural functions of music, physiological arousal, and familiarity. Data were collected in a lab study and in an online survey (total N = 263). Participants listened to six pieces of distinct musical styles (and to their own favorite music in the lab study). They had to indicate how much they liked the music and how much they agreed with a list of statements concerning the parameters mentioned above for each piece. Multiple regressions revealed that all parameters (except cultural functions) accounted significantly for the strength of music preference. The cognitive functions of music (i.e., music as a means for communication and self-reflection), as well as physiological arousal elicited by the music, were the most important determinants of music preference. The results are discussed in the light of several assumptions about the evolutionary foundation of music listening. In addition, the present findings may serve as a basis for the construction of an empirically derived theory of music preference. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Are judgments of the positional frequencies of letters systematically biased due to availability?

How do people estimate whether a particular letter is more frequent in the 1st versus in a later position? The authors tested 2 precise versions of the availability hypothesis, a hypothesis that assumes that frequency processing occurs on the level of the phonological classes of vowels and consonants, and the regressed-frequencies hypothesis, which assumes monitoring of individual letters. Across 3 studies, it was found that (a) judgments of whether a letter is more frequent in the 1st or the 2nd position generally followed the actual proportions and (b) the estimated relative frequencies in the 1st versus the 2nd position closely agreed with the actual rank ordering, except for an overestimation of low and underestimation of high values. These results favor the regressed-frequencies hypothesis and challenge the conclusions about frequency judgments in the heuristics and biases literature. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Do studies of statistical power have an effect on the power of studies?

The long-term impact of studies of statistical power is investigated using J. Cohen's (1962) pioneering work as an example. We argue that the impact is nil; the power of studies in the same journal that Cohen reviewed (now the Journal of Abnormal Psychology) has not increased over the past 24 years. In 1960 the median power (i.e., the probability that a significant result will be obtained if there is a true effect) was .46 for a medium size effect, whereas in 1984 it was only .37. The decline of power is a result of alpha-adjusted procedures. Low power seems to go unnoticed: only 2 out of 64 experiments mentioned power, and it was never estimated. Nonsignificance was generally interpreted as confirmation of the null hypothesis (if this was the research hypothesis), although the median power was as low as .25 in these cases. We discuss reasons for the ongoing neglect of power. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Zur Funktionalit?t der photometrischen Skatolbestimmung bei Schlachtschweinen

Zusammenfassung Bei Schlachttiergruppen von 264 Ebern, Kryptorchiden und Zwittern wurden mit Hilfe einer in Dänemark entwickelten photometrischen Skatolbestimmung für Speckproben im Durchschnitt 0.14 ppm und für Flomenproben durchschnittlich 0.18 ppm Skatoläquivalente gemessen. Über dem für Ebergeruch festgelegten Grenzwert von 0.25 ppm lagen dabei 10.6% der Speck- und 16.3% der Flomenproben. — Da die photometrische Bestimmung von Skatol im Fett von Schweinen auf einer relativ unspezifischen Farbreaktion (nach Ehrlich) basiert, werden auch andere Indolderivate — vor allem die des Tryptophanabbaues — miterfaßt. Deshalb müssen die Ergebnisse als Skatoläquivalente (SE) angegeben werden. Im Vergleich zur HPLC-Methode wurden bei der photometrischen Skatolbestimmung in beiden Probenkollektiven zu hohe Werte gefunden, das Indol war mit einem beträchtlichen Anteil stets als Skatolbegleiter beteiligt, die übrigen Skatoläquivalente scheinen jedoch eine untergeordnete Rolle zu spielen.

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On the efficiency of photometric determination of skatole in slaughtered pigs

In a group of 264 boars, including both cryptorchides and hermaphrodites, skatole was measured using a photometric method developed in Denmark. It resulted in a concentration of skatole equivalents (SE) in the fat of 0.14 ppm in belly tissue and 0.18 ppm in flomen tissue on average, respectively. 10.6% of belly and 16.3% of flomen tissue exceeded the limiting value of 0.25 ppm skatole for boar taint. The photometric determination of skatole is based on a relatively unspecific reaction according to Ehrlich. Therefore, other derivates of indole concerning the decomposition of tryptophan are recorded, and the results must be declared as SE. In comparison with HPLC, the photometric method yields values that are too high, indole is always found with skatole in a considerable amount, and the other skatole equivalents seem to play a subordinate part.

     

The Hazards of Underspecified Models: The Case of Symmetry in Everyday Predictions.

[Correction Notice: An erratum for this article was reported in Vol 115(1) of Psychological Review (see record 2008-00265-009). On p. 772 (Real Data section), some numbers were listed incorrectly. The correct numbers are as follows: For soccer world championships (1930-1978), number of games in which a given team both won and led at halftime = 151, number of games in which a team won the game = 243, number of games in which a team led at halftime = 196, P(WinMid|WinEnd) = .62, and P(WinEnd|WinMid) = .77. For the German Bundesliga (1994-1995), number of games in which a given team both won and led at halftime = 132, number of games in which a team won the game = 223, number of games in which a team led at halftime = 174, P(WinMid|WinEnd) = .59, and P(WinEnd|WinMid) = .76. The conditional probabilities are referred to again on p. 778. There, it should read "These quotients correspond to P(WinMid|WinEnd)/P(WinEnd|WinMid), the empirical values of which were found to be .81 and .78 (.62/.77 and .59/.76, see above)."] Should one be more confident when predicting the whole (or an event based on a larger sample) from the part (or an event based on a smaller sample) than when predicting the reverse? The relevant literature on judgment under uncertainty argues that such predictions are symmetrical but that, as an empirical matter, people often fail to appreciate this symmetry. The authors show that symmetry in prediction does not necessarily hold. In addition to an empirical study involving predictions about soccer games, they develop a theoretical model showing that, at least for the ranges of numerical values usually found in everyday judgment problems, symmetry in predictions is uncommon when 2 different sample sizes are involved. The complexity of the theoretical model used in this analysis raises questions about model specification in judgmental research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

FPGA-based parallel ASIP architecture for reactive systems

A scalable parallel ASIP architecture based on FPGAs suitable For the implementation of reactive systems is described. The specification language used is extended statecharts. An industrial example requiring the real-time control of several stepper motors illustrates the benefits of the approach     

Scalable processor architecture for Java with explicit threadsupport

A scalable processor architecture for multi-threaded Java^TM applications is presented. The proposed architecture consists of multiple application-specific processing elements, each able to execute a single thread at one time. The architecture is evaluated by implementing a portable and scalable Java machine on an FPGA board for demonstration