Effects of varying trial distribution,intra- and extramaze cues,and amount of reward on proactive interference in the radial maze

Rats are typically less accurate in their arm selections in the radial maze over successive trials in a session (Roberts & Dale, 1981). In the present study, rats’ choice accuracy declined when such trials were separated by 2-min (massed) but not by 2-h (spaced) intertriai intervals. Changing intramaze visual/tactile arm stimuli (Experiments 1 and 3) or extramaze landmark stimuli (Experiment 4) between trials weakened the massed-trials effect, but changing the number of food pellets per arm, either alone or in conjunction with changes in intramaze cues (Experiments 2 and 3), did not. The rats also tended to avoid the spatial locations of their last four choices on a previous trial during their first four choices on a current trial, and more so with massed than with spaced trials. These findings indicate that intertriai proactive interference (PI) occurred only with massed trials and was weakened by changing intra- and extramaze cues between such trials.     

Effects of Linking Methods on Detection of DIF

Studies of differential item functioning under item response theory require that item parameter estimates be placed on the same metric before comparisons can be made. The present study compared the effects of three methods for linking metrics: a weighted mean and sigma method (WMS); the test characteristic curve method (TCC); and the minimum chi-square method (MCS), on detection of differential item functioning. Both iterative and noniterative linking procedures were compared for each method. Results indicated that detection of differentially functioning items following linking via the test characteristic curve method gave the most accurate results when the sample size was small. When the sample size was large, results for the three linking methods were essentially the same. Iterative linking provided an improvement in detection of differentially functioning items over noniterative linking particularly with the .05 alpha level. The weighted mean and sigma method showed greater improvement with iterative linking than either the test characteristic curve or minimum chi-square method.     

A worldwide intercultural network: exploring electronic messaging for instruction

A worldwide international computer network has been developed to provide students from different cultures with opportunities to work cooperatively. Prototype activities have been developed and tested which facilitate and contextualize interactions among secondary and college students. Joint projects in language, science and social studies are carried out using an overnight electronic network to coordinate parallel surveys and to exchange findings of joint research. The instructional utility of these activities and the technical and organizational aspects of the network are discussed. Receiving-end translation as a method for achieving understanding across languages is reported.     

Assessment for Effective Intervention: Enrichment Science Academic Program

Israel suffers from a growing problem of socio-economic gaps between those who live in the center of the country and residents of outlying areas. As a result, there is a low level of accessibility to higher education among the peripheral population. The goal of the Sidney Warren Science Education Center for Youth at Tel-Hai College is to strengthen the potential of middle and high school students and encourage them to pursue higher education, with an emphasis on majoring in science and technology. This study investigated the implementation and evaluation of the enrichment science academic program, as an example of informal learning environment, with an emphasis on physics studies. About 500 students conducted feedback survey after participating in science activities in four domains: biology, chemistry, physics, and computer science. Results indicated high level of satisfaction among the students. No differences were found with respect to gender excluding in physics with a positive attitudes advantage among boys. In order to get a deeper understanding of this finding, about 70 additional students conducted special questionnaires, both 1 week before the physics enrichment day and at the end of that day. Questionnaires were intended to assess both their attitudes toward physics and their knowledge and conceptions of the physical concept “pressure.” We found that the activity moderately improved boys’ attitudes toward physics, but that girls displayed decreased interest in and lower self-efficacy toward physics. Research results were used to the improvement of the instructional design of the physics activity demonstrating internal evaluation process for effective intervention.     

Organization of attack and other behaviors of White King pigeons exposed to intermittent water presentations

Six water-deprived pigeons were exposed to a fixed-time 90-sec water schedule with and without a conspecific target available. Target contacts and the pigeon’s location in the test chamber during the interreinforcement interval were recorded, and the results were compared with those previously obtained with food reinforcement. Prior to target introduction, water-reinforced birds spent more total time in the front near the reinforcer dispenser and less in the rear than food-reinforced birds and, unlike food-reinforced birds, exhibited postreinforcement drinking-like behaviors near the reinforcer dispenser before moving away from that area. With the target available, the level, topography, and duration of target-directed biting pecks were comparable for food- and water-reinforced pigeons. In contrast, the temporal organization of target pecks reflected the different temporal and spatial organizations of behavior prior to target introduction. For both food- and water-reinforced birds, the time between reinforcers at which a bird was spatially situated halfway between the front and rear of the chamber prior to target presentation was positively correlated with the time at which maximum target contact subsequently occurred.     

Assessing early arithmetic abilities: Effects of verbal and nonverbal response types on the calculation performance of middle-and low-income children

In two studies, we compared young children's performance on three variations of a nonverbally presented calculation task. The experimental tasks used the same nonverbal mode of presentation but were varied according to response type: (1) putting out disks (nonverbal production); (2) choosing the correct number of disks from a multiple-choice array (nonverbal recognition); and (3) giving a number word (verbal production). The verbal production task required children to map numerosities onto the conventional number system while the nonverbal production and nonverbal recognition tasks did not. Study 1 showed that the performance of 3-, 4- and 5-year-old middle-income children (N = 72) did not vary with the type of response required. Children's answers to nonverbally presented addition and subtraction problems were available in both verbal and nonverbal forms. In contrast. Study 2 showed that low-income children (3- and 4-year-olds; N = 48) performed significantly better on both nonverbal response type tasks than on the verbal response type task. Analysis of individual data indicated that a number of the low-income children were successful on the completely nonverbal calculation tasks, even though they had difficulty with verbal counting (i.e., set enumeration and cardinality). The findings suggest that the ability to calculate does not depend on mastery of conventional symbols of arithmetic.