Do young children think of television images as pictures or real objects?

Three studies investigated whether 3‐ and 4‐year‐olds interpret television images as mere pictorial representations of objects or as real, physically‐present objects. Four‐year‐olds gave clear evidence of making the former interpretation whereas 3‐year‐olds seemed to make the latter one. However, the data suggest that the younger children's errors reflect a failure to differentiate conceptually between television images and their referent objects rather than a conviction that real objects populate television sets.     

崭新的婚礼

“如果那是幸运,那也不是我希望艾琳得到的那种幸运。”老实说,当我们的艾琳告诉我她准备结婚时,我的心情并不好。唉,我知道他是个翩翩少年或是诸如此类的人,但我还是极力表现出些许热情,使得她不会问我他怎么了,也不会继续缠着我,说她不算年轻,可以嫁人了。这些天,我感到身心非常疲倦,以至于一个孩子转身扑向我时,我被弄得筋疲力尽。不管怎样,既然我自已不到20岁就结婚了,那么我有什么资格要求她再等     

Fraction Instruction for Students with Mathematics Disabilities: Comparing Two Teaching Sequences

Abstract. This study investigated the effects of teaching middle school students with mathematics disabilities equivalent fraction concepts and procedures using the concrete‐representational‐abstract (CRA) instructional sequence or the representational‐abstract (RA) instructional sequence. Twenty‐six students formed the CRA group, and 24 students formed the RA group. The two treatment groups received carefully sequenced instruction over 10 lessons. The only difference between the two treatment groups was that the CRA group used concrete manipulative devices for the first three lessons while the RA group used representational drawings. Analyses of the data indicated that students in both treatment groups improved overall in their understanding of fraction equivalency from pretest to posttest. On all achievement measures, students in the CRA group had overall higher mean scores than did students in the RA group. Implications for classroom instruction and suggestions for further research are discussed.     

Behavioral contrast as a function of component duration and baseline rate of reinforcement

Three experiments examined changes in size of multiple-schedule behavioral contrast with changes in an independent variable. Experiment 1 found that positive contrast generally increased with increases in component duration when pigeons pressed treadles. Experiments 2 and 3 found that positive and negative contrast generally increased with increases in the baseline rates of reinforcement when pigeons pecked keys. The experiments show that positive and negative contrast vary as similar functions of the same variables. Experiment 1 also suggests that these functions are different for different responses.