The role of proctoring in personalized instruction

The effect of amount of student-proctor interaction was investigated within the framework of Keller's (1968) method of personalized instruction. College students enrolled in introductory psychology were randomly assigned to five groups: 0%, 25%, 50%, 75%, and 100%, reflecting the percentage of units on which each student was proctored. The results indicated that (a) the proctored students were superior to the non-proctored students as measured by final examination performance, (b) for the proctored groups, the amount of proctoring did not differentially affect final examination performance, and (c) the major effect of increased proctoring was an acceleration of the rate of progress through the course.     

Effects of a DRL contingency added to a fixed-interval reinforcement schedule

Following 30 days of reinforcement for the bar press response of two white rats on 30-sec fixed-interval (FI), a DRL component was added so that a minimal interresponse time (IRT) for the reinforced response, in addition to the FI variable, was necessary for reinforcement. Marked control over response rate by the superimposed DRL requirement was demonstrated by an inverse hyperbolic function as the DRL component was increased from 1 to 24 sec within the constant 30-sec FI interval. Interresponse time and post-reinforcement (post-S^R) “break” distributions taken at one experimental point (DRL = 24 sec) suggested that a more precise temporal discrimination was initiated by an S^R than by a response, since the relative frequency of a sequence of two reinforced responses appeared greater than that of a sequence of a non-reinforced response followed by a reinforced one. This latter finding was confirmed with new animals in a follow-up experiment employing a conventional 24-sec DRL schedule.     

Some parameters of behavioral contrast and allocation of interim behavior in rats

Two experiments examined the effects of baseline reinforcement rate and component duration on behavioral contrast and on re-allocation of interim behavior in rats. Positive behavioral contrast occurred during multiple variable-interval 10-second extinction (VI 10 EXT) after a multiple VI 10 VI 10 baseline condition, but not during multiple VI 60 EXT following multiple VI 60 VI 60 baseline. Component duration had no significant effect on contrast. These results differed from those found in studies of pigeons' key pecking. Contrast was accompanied by an increased rate of drinking in the changed component, but drinking in the constant component did not decrease. These results are not consistent with the competition theory of contrast, but are consistent with the predictions based on the matching law. However, no current theory seems to account for all instances of behavioral contrast.     

Horses (<Emphasis Type="Italic">Equus caballus</Emphasis>) use human local enhancement cues and adjust to human attention

This study evaluates the horse (Equus caballus) use of human local enhancement cues and reaction to human attention when making feeding decisions. The superior performance of dogs in observing human states of attention suggests this ability evolved with domestication. However, some species show an improved ability to read human cues through socialization and training. We observed 60 horses approach a bucket with feed in a three-way object-choice task when confronted with (a) an unfamiliar or (b) a familiar person in 4 different situations: (1) squatting behind the bucket, facing the horse (2) standing behind the bucket, facing the horse (3) standing behind the bucket in a back-turned position, gazing away from the horse and (4) standing a few meters from the bucket in a distant, back-turned position, again gazing away from the horse. Additionally, postures 1 and 2 were tested both with the person looking permanently at the horse and with the person alternating their gaze between the horse and the bucket. When the person remained behind the correct bucket, it was chosen significantly above chance. However, when the test person was turned and distant from the buckets, the horses’ performance deteriorated. In the turned person situations, the horses approached a familiar person and walked towards their focus of attention significantly more often than with an unfamiliar person. Additionally, in the squatting and standing person situations, some horses approached the person before approaching the correct bucket. This happened more with a familiar person. We therefore conclude that horses can use humans as a local enhancement cue independently of their body posture or gaze consistency when the persons remain close to the food source and that horses seem to orientate on the attention of familiar more than of unfamiliar persons. We suggest that socialization and training improve the ability of horses to read human cues.     

Mental Health and Other Service Use by Youth in Therapeutic Foster Care and Group Homes

Little is known about what additional services youth receive while they reside in out-of-home treatment settings. However, such information may be crucial for explaining effectiveness and variation in outcomes for youth in such settings. Our research examines patterns of multi-sector service use for youth in two settings—Therapeutic Foster Care and group homes. Data come from in-person interviews with Treatment Foster Parents and Group Home Staff for a NC state-wide sample of youth with psychiatric disorders and aggressive behavior. Findings indicated high rates of service use by youth in both settings. Analyses indicated significant differences in service types used by youth in each setting, yet similar volume of service use between settings. Clinical and demographic factors did not significantly influence types of services received. Differences in service patterns between the two groups indicated that youth in TFC were more likely to receive community-based, individualized services while youth in group homes were more likely to receive more restrictive services.     

Exploring Risk in Early Adolescent African American Youth

Two studies were conducted to explore the degree to which single- and multiple-risk profiles were evident in samples of African American early adolescents in low-income inner-city, rural, and suburban schools. Study 1 examined early adolescent risk status (i.e., single, multiple) in relation to later adjustment in a representative sample (70% European American, 30% African American). Youth who experienced a single risk in early adolescence had moderately increased levels of school dropout and criminal arrests, whereas youth with multiple risks (i.e., combination of 2 or more risks) had significantly increased levels of school dropout, criminal arrests, and teen parenthood. Study 2 examined the extent to which single- and multiple-risk profiles were evident in cross-sectional samples of African American youth from low-income inner-city and rural areas. About one fourth of both the inner-city and rural samples of African American youth were composed of youth in the single-risk category. A significantly greater proportion of boys in the inner-city sample (20%) than boys in the rural sample (13%) experienced multiple risks. Girls across the rural and inner-city samples did not differ in terms of risk. Overall, more than 60% of African American youth in these two low-income samples did not evidence risk for later adjustment problems. Implications for research and intervention are discussed.     

Rejected bullies or popular leaders? The social relations of aggressive subtypes of rural african american early adolescents

Teacher assessments of interpersonal characteristics were used to identify subtypes of rural African American early adolescents (161 boys and 258 girls). Teacher ratings of interpersonal characteristics were used to identify popular and unpopular aggressive subtypes for both boys and girls. Unpopular aggressive youths did not have elevated levels of rejected sociometric status but were more likely to have lower levels of peer-perceived social prominence and social skills. Conversely, popular aggressive youths were more likely to be disliked by peers even though they were perceived by peers as socially prominent and socially skilled and were identified by teachers as highly involved in extracurricular activities. Both popular and unpopular aggressive youths tended to associate with others who had similar levels of peer-perceived popularity.     

The development and psychometric evaluation of a new measure of dissociative activities

The psychometric properties of a new measure of dissociative behaviors, the Scale of Dissociative Activities (SODAS), were evaluated. Undergraduates (n = 533) completed the SODAS, 2 other established self-report measures of dissociative behaviors, and a measure of socially desirable responding. A randomly selected subset of participants (n = 100) also participated in an additional reliability and validity follow-up study. The SODAS was found to be internally consistent (a =.95) and temporally stable (r =.77) over an average 38-day interval. The validity of the SODAS was established by a moderately low negative correlation with social desirability, high correlations with other self-report measures of dissociation, and moderate to high correlations with samples of dissociative activities assessed in naturalistic environments with experience sampling methodology. Overall, the SODAS compared favorably to other existing self-report measures of dissociative behaviors. Directions for future research on the SODAS are discussed.     

Cognitive deficits related to major organ failure: The potential role of neuropsychological testing

Until recently, little attention has been paid to the possibility of cognitive deficits in patients with disease or failure of major organs such as the liver, kidney, or heart. However, there is a growing awareness that major organ failure often has neuropsychological sequelae. These sequelae may at times be quite subtle and not detectable under gross. examination. Nevertheless, even subtle deficits may have a major impact on adherence to medical regimens, psychosocial adjustment, and quality of life of patients. Neuropsychological assessment has a potentially valuable role to play both in research and in clinical work. It can be useful in adding to our knowledge of the cognitive effects of various types, severity and duration of major organ disease, as well as sequelae associated with treatment. It also is a potentially valuable clinical tool for identifying cognitive deficits that will affect the quality of life and probability of survival for organ failure patients.     

A Set Theory with Support for Partial Functions

Partial functions can be easily represented in set theory as certain sets of ordered pairs. However, classical set theory provides no special machinery for reasoning about partial functions. For instance, there is no direct way of handling the application of a function to an argument outside its domain as in partial logic. There is also no utilization of lambda-notation and sorts or types as in type theory. This paper introduces a version of von-Neumann-Bernays-Gödel set theory for reasoning about sets, proper classes, and partial functions represented as classes of ordered pairs. The underlying logic of the system is a partial first-order logic, so class-valued terms may be nondenoting. Functions can be specified using lambda-notation, and reasoning about the application of functions to arguments is facilitated using sorts similar to those employed in the logic of the IMPS Interactive Mathematical Proof System. The set theory is intended to serve as a foundation for mechanized mathematics systems.