Note on two generalizations of coefficient alpha

An important relationship is given for two generalizations of coefficient alpha, Rajaratnam, Cronbach and Gleser's generalizability formula for stratified-parallel tests and Raju's coefficient beta.The author gratefully acknowledges the generous assistance given by reviewers and the editor.     

On kristof's test for a linear relation between true scores of two measures

The hypothesis that two variables have a perfect disattenuated correlation and hence measure the same trait, except for errors of measurement, is discussed. Equivalently, the underlying variables, the true scores, are related linearly. We show that several previously proposed ad hoc tests are in fact likelihood ratio tests. The cases when the linear relation is specified and when it is unspecified are both discussed.This work was done while the author was at Purdue University Under Air Force Grant AFOSR-72-2350B.     

Discriminated response and incentive processes in operant conditioning: a two-factor model of stimulus control

Understanding stimulus control generated in instrumental learning requires the direct investigation of discriminated response and reinforcer (incentive) processes acquired exclusively through the response-reinforcer contingencies operating on complex (multicomponent) baselines. Two series of stimulus-compounding studies accomplished this direct investigation. In one series, the independent variable was the relative reinforcement between schedule components; in the second series, it was relative response rate between components. Stimulus-compounding tests revealed that response and incentive processes enhanced each other when in agreement, counteracted each other when in opposition, and produced intermediate results when only one factor was operating. This pattern of results led to the conclusion that these factors were algebraically combining and to the development of a response/incentive matrix reflecting these dynamics. This two-factor analysis was extended to the peak-shift effect in stimulus generalization experiments and to the generation of inhibitory control. Two decades of stimulus compounding and peak-shift research were organized within this two-factor framework, extending this traditional approach to learning to active research areas heretofore not systematically considered in these terms.     

The role of physical identity of the sample and correct comparison stimulus in matching-to-sample paradigms

Pigeons were trained in a higher-order conditional discrimination paradigm to assess the role of physical identity in a within-subjects design. A line orientation which was super-imposed on all response keys signalled whether a response to the matching color or a response to the nonmatching color was correct. Following training under this paradigm, stimulus control gradients were obtained by varying the angularity of the lines. Orderly gradients of stimulus control were obtained and no bias toward or away from the physically identical comparison stimulus was observed. The data were interpreted as indicating that the pigeons acquired a discrimination for each specific stimulus configuration or a set of specific stimulus-response chains based on compound stimuli in which physical identity played no special role.     

Training generalized improvisation of tools by preschool children

The development of new, "creative" behaviors was examined in a problem-solving context. One form of problem solving, improvisation, was defined as finding a substitute to replace the specifically designated, but currently unavailable, tool ordinarily used to solve the problem. The study examined whether preschool children spontaneously displayed generalized improvisation skills, and if not, whether they could be trained to do so within different classes of tools. Generalization across different tool classes was monitored but not specifically trained. Five preschool children participated in individual sessions that first probed their skill at improvising tools, and later trained and probed generalized improvisation in one or more of three tool classes (Hammers, Containers, and Shoelaces), using a multiple-baseline design. All five children were trained with Hammers, two were trained in two classes, and two were trained in all three tool classes. Four of the five children improvised little in Baseline. During Training, all five showed increased generalized improvisation within the trained class, but none across classes. Tools fabricated by item combinations were rare in Baseline, but common in Training. Followup probes showed that the training effects were durable.     

THE EFFECTIVENESS OF VERBAL INSTRUCTION ON TEACHING BEHAVIOR-MODIFICATION SKILLS TO NONPROFESSIONALS1

The effectiveness of a mastery criterion, lecture-based training program for teaching behavior modification to sheltered workshop personnel was evaluated. Staff performance was assessed in terms of: (1) verbal proficiency, as determined from a pre- and posttraining written exam, and (2) application proficiency, as measured by the frequency and appropriateness of staff responses to client behaviors. A direct count was made of the number of positive, negative, and neutral statements following client appropriate and inappropriate behaviors, and the number and type of client behaviors ignored. Thus, it was possible to determine the extent of generalization from classroom to applied settings, as well as the appropriateness of lectures for training specific performance skills. Lecture units introduced stimulus control procedures, shaping-chaining, and contingency management. Characteristic features of the training program were frequent testing, study objectives, immediate remediation, and contingent reinforcement. Verbal instruction was shown to be effective in improving subjects' verbal skills concerning behavior-modification principles, while only partially effective in improving application skills. There was an increase in the total number of staff-client interactions observed for all subjects, but only two of the response classes emphasized in the training program (reinforcing desirable client behavior and ignoring undesirable behavior) showed considerable improvement over pretraining levels. Despite this partial improvement, verbal instruction alone was shown to be insufficient for teaching the full range of behavior-modification skills required to function effectively in applied settings.     

中学生创造性思维能力自评测验的编制

创造性思维有多种构成,其能力表现也有多种,即创造性思维能力是多维结构的.常用的最佳表现测验形式,无法良好测量其多维结构.一些研究者认为创造性思维能力是个体内在稳定的智力品质,并尝试使用典型表现测验来测量.本研究沿用此思路,尝试开发一套中学生创造性思维能力自评测验,即测查个体在日常生活中是否具有一些典型的习惯或行为方式.采用理论的探讨与实证分析相结合的方法,取得如下结果:(1)确定创造性思维能力的10维测评结构;(2)经过两轮测试检验,形成正式测验,信效度良好.     

Relationship of temporal lobe volumes to neuropsychological test performance in healthy children

Ecological validity of neuropsychological assessment includes the ability of tests to predict real-world functioning and/or covary with brain structures. Studies have examined the relationship between adaptive skills and test performance, with less focus on the association between regional brain volumes and neurobehavioral function in healthy children. The present study examined the relationship between temporal lobe gray matter volumes and performance on two neuropsychological tests hypothesized to measure temporal lobe functioning (visual perception-VP; peabody picture vocabulary test, third edition-PPVT-III) in 48 healthy children ages 5-18 years. After controlling for age and gender, left and right temporal and left occipital volumes were significant predictors of VP. Left and right frontal and temporal volumes were significant predictors of PPVT-III. Temporal volume emerged as the strongest lobar correlate with both tests. These results provide convergent and discriminant validity supporting VP as a measure of the "what" system; but suggest the PPVT-III as a complex measure of receptive vocabulary, potentially involving executive function demands.     

视知觉学习的认知与神经机制研究

知觉学习是指由于训练或经验而引起的长期稳定的知觉变化,是一种内隐性的学习。近20年来,视知觉学习的大量研究结果提示大脑皮层的各个区域,甚至包括初级感觉皮层,在成熟之后仍然具有一定的可塑性。该文根据近年来的研究进展,对视知觉学习在大脑的什么地方,什么时候,以何种方式发生等热点问题进行了探讨。研究提示,视知觉学习涉及了包括初级视皮层在内的多个大脑皮层,并且存在一种自上而下的调控机制;视知觉学习可以在不同的时间尺度上发生,快速学习之后将伴随着慢速学习;通过视知觉学习,人们对于复杂物体的表征将从高级皮层区域移向低级皮层区域,任务执行也将趋于自动化     

EQUIVALENCE CLASS FORMATION: A METHOD FOR TEACHING STATISTICAL INTERACTIONS

Many students struggle with statistical concepts such as interaction. In an experimental group, participants took a paper‐and‐pencil test and then were given training to establish equivalent classes containing four different statistical interactions. All participants formed the equivalence classes and showed maintenance when probes contained novel negative exemplars. Thereafter, participants took a second paper‐and‐pencil test. Participants in the control group received two versions of the paper‐and‐pencil test without equivalence‐based instruction. All participants in the experimental group showed increased paper‐and‐pencil test scores after forming the interaction‐indicative equivalence classes. Class‐indicative responding also generalized to novel exemplars and the novel question format used in the paper‐and‐pencil test. Test scores did not change with repetition for control group participants. Implications for behavioral diagnostics and teaching technology are discussed.