Abstract. Living in groups should promote the cultural transmission of a novel behaviour because opportunities for observing knowledgeable individuals are likely to be more numerous in this condition. However, in this study pigeons who shared the food discoveries of others (scroungers) did not learn the food-finding technique used by the discoverers (producers). Individually-caged pigeons prevented from scrounging easily learned the technique from a conspecific tutor. When caged pigeons obtained food from the tutor's performance, most nai've observers failed to learn. In a flock, scroungers selectively followed producers. In individual cages, scrounging during the tutor's demonstration was equivalent to getting no demonstration at all. This effect of scrounging did not interfere with subsequent acquisition of the foodfinding behaviour when scrounging was no longer possible. Many animals are known to adopt a novel behaviour as a result of observing others performing it (see Galef 1976; Bonner 1980; Mainardi 1981 for reviews). This type of learning has been variously labelled cultural transmission, social learning, imitation, observational learning, etc. One consequence

Abstract One-tailed statistical tests are often used in ecology, animal behaviour and in most other fields in the biological and social sciences. Here we review the frequency of their use in the 1989 and 2005 volumes of two journals (Animal Behaviour and Oecologia), their advantages and disadvantages, the extensive erroneous advice on them in both older and modern statistics texts and their utility in certain narrow areas of applied research. Of those articles with data sets susceptible to one-tailed tests, at least 24 % in Animal Behaviour and at least 13 % in Oecologia used one-tailed tests at least once.They were used 35 % more frequently with nonparametric methods than with parametric ones and about twice as often in 1989 as in 2005. Debate in the psychological literature of the 1950s established the logical criterion that one-tailed tests should be restricted to situations where there is interest only in results in one direction. ‘Interest ’ should be defined; however, in terms of collective or societal interest and not by the individual investigator. By this ‘collective interest ’ criterion, all uses of one-tailed tests in the journals surveyed seem invalid. In his book Nonparametric Statistics, S. Siegel unrelentingly suggested the use of one-tailed tests whenever the investigator predicts the direction of a result.That work has been a major proximate source of confusion on this issue, but so are most recent statistics textbooks. The utility of one-tailed tests in research aimed at obtaining regulatory approval of new drugs and new pesticides is briefly described, to exemplify the narrow range of research situations where such tests can be appropriate.These situations are characterized by null hypotheses stating that the difference

This study empirically investigated the validity and utility of the stratified adaptive computerized testing model Istradaptive]deeloped by Weiss (1973). The model presents a tailored testing strategy based on Binet IQ measurement theory and Lord's (1972) modern test theory. Nationally normed School and Coilege Ability Test Verbal analogy items (SCAT-01) were used to construct an item pool. Item difficulty and discrimination indices were resealed to normal ogive parameters on 249 items. Freshmen volunteers at Florida State University were randomly assigned to stradaptive or conventional test groups. Both groups were tested via cathode-ray-tube (CRT) terminals coupled to a Control Data Ctoration 6500 computer. The conventional tibjects took a SCAT-N to t, while the stradaptive group took.individually,tAilored tests drawn from the sate item, pool. Results showed significantly. higher

Thirty experienced music listeners tried to set an optimum 'wetto -dry signal ratio' of the resulting mixed sound by adjusting the soft knob of the Lexicon 300 digital audio processor for eight different factory-installed room simulation effects. A preprocessed two-channel stereo studio recording of classical music was used as the input 'dry' signal. Results showed that experiment participants could be divided into two diverse groups, one of which preferred markedly greater values of the 'wet' signal than the other. The group of 'wet' sound advocates was composed largely of sound engineers, while the 'dry' sound preference came from acousticians and musicians. An approximately linear dependence of the optimal level difference of the input 'dry' signal and the processed 'wet' signal on the simulated reverberation time was found. This finding is in agreement with the conclusions of the psychoacoustical experiment carried out by Schmidt in three-dimensional synthetic sound field [9].

Based on Coroners ' verdicts, fatigue of car or truck drivers was a contributing factor in 9.1 % of fatal accidents involving trucks. Based on the presence of factors such as extended driving hours, falling asleep at the wheel, comments about tiredness, driving right of centre and night-time driving, the authors estimated fatigue contributed to 19.9 % of the accidents. There were approximately equal numbers of fatigued car drivers and truck drivers. An analysis of casualty and fatal truck accidents by time of day (adjusted for exposure) showed that accident risks were highest during the night on all five Victorian highways studied. Driver fatigue is one of the possible factors underlying this pattern of elevated risk. The report section described in-vehicle fatigue counter-measures. The distinction between fatigue monitors and alerting devices was made and it was recommended that eye closure and head nodding monitors and an alerting device be tested in the next stage of this project. Key Words: Fatigue (human), accident rate, fatality,

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The Botswana Examination Council (BEC) uses forecast grades obtained from secondary school Agriculture teachers to review component 2 of Agriculture final examination. Moderation of component 2 could help to improve candidate’s final grade. This descriptive-correlational study purports to determine which of the component 1, component 2, and component 3 of the BGCSE Agriculture could be used to predict students ’ forecast grades. Examination scores spanning seven years (2001 – 2007), were obtained from BEC records. Two senior secondary schools were randomly selected from each of the five Educational Regions in Botswana, and then a systematic random sample of candidates with their respective scores was obtained from each of the selected schools. A multiple regression analysis was conducted using a backward procedure and it revealed that all the components 1, 2 and 3 significantly predicted forecast grades. Components 2 shared the largest (31.6%) variability with forecast scores. It was recommended that teachers should use composite scores from different school-based assessments to determine forecast grades.

Abstract not found

If two stimuli are presented to an octopus simultaneously, but at different distances from the animal, the nearer of the two is usually attacked. This preference was used to test the ability of octopuses to discriminate distance. White discs, 37 mm in diameter, were used as stimuli, and two parameters were varied: the distance of the farther stimulus from the animal (D), and the difference between the distances of the farther and nearer stimulus (d). Animals chose the nearer stimulus on 70 % of occasions under the most difficult conditions used, where D was 370 mm and d was 50 mm. This percentage increased as D decreased or d increased. Further tests showed that varying the size of the discs, or using white vertical or horizontal rectangles instead of discs as stimuli, did not affect performance. The most likely cue being used by the animals to discriminate distances is accommodation. If this is the case octopuses can detect blurring of points on the retinal image comparable in size to a single retinal receptor, and lens displace-ments of around