An approximation of theK outN reliability of a test,and a scoring procedure for determining which items an examinee knows

Consider any scoring procedure for determining whether an examinee knows the answer to a test item. Letx _i = 1 if a correct decision is made about whether the examinee knows the ith item; otherwisex _i = 0. Thek out ofn reliability of a test isρ _k = Pr (Σx _i ≥k). That is,ρ _k is the probability of making at leastk correct decisions for a typical (randomly sampled) examinee. This paper proposes an approximation ofρ _k that can be estimated with an answer-until-correct test. The paper also suggests a scoring procedure that might be used whenρ _k is judged to be too small under a conventional scoring rule where it is decided an examinee knows if and only if the correct response is given.     

“in”, “on”, and “under” revisited

The present study presents evidence that young children's comprehension of the locatives ‘in’, ‘on’, and ‘under’ is, at least in part, contextually determined. Children aged 1;6–3;0 were given tasks with verbal instructions which were either contextually congruent or incongruent. The results were interpreted in terms of the non-linguistic as well as linguistic strategies apparently used to interpret speech. The results and interpretation are in contrast to those of earlier research.     

Intervention in the Library: The Effect of Increased Responsibility on Bystanders' Willingness To Prevent a Theft

Two field experiments tested the hypothesis that a bystander's increased responsibility to act increases the likelihood of his helping the victim of an emergency. In Experiment 1, an individual asked or did not ask the bystander to protect his property in his absence. In Experiment 2, the presence/absence of an unattentive confederate was varied orthogonally to the request/no request manipulation. The results of both experiments indicated that bystanders who received a prior request for protective assistance felt more personally responsible for protecting the individual's property and were more likely to prevent a theft of that property than were bystanders who received no request. The presence of a confederate in Experiment 2 decreased bystanders' felt responsibility and their willingness to intervene on the victim's behalf. The results were interpreted as support for the "felt responsibility" proposition of the Latané and Darley (1970) model of bystander intervention.     

“Generalized imitation” on a nonimitative task: Effects of modeling and task history

Two experiments investigated characteristic generalized imitation procedures on a nonimitative successive visual discrimination task. In Experiment I, no discriminative behavior was obtained though a number of procedures designed to enhance discrimination were employed. The introduction of a differential modeling procedure after nine or 10 sessions of nondifferential performance was ineffective in producing differential responding for three of four Ss. In the second experiment, the differential modeling procedure was introduced as an initial manipulation and was successful in establishing discriminative performance in all Ss. After several sessions of differential responding, the observation of a model performing nondifferentially was relatively ineffective in altering the pattern of responding. These results suggest (1) that modeling may be functional in altering a S's behavior depending on what point in the procedures the manipulation is introduced and (2) that certain procedural variables may define a functional response class characterized by the failure to develop discriminative responding.     

Adolescent Nonsmokers,Triers, and Regular Smokers' Estimates of Cigarette Smoking Prevalence: When Do Overestimations Occur and by Whom?1

The present study tested three assumptions often made by smoking prevention researchers and practitioners regarding the nature and causes of smoking prevalence estimates. Specifically, it is often assumed that (a) adolescent prevalence estimates of all levels of smoking are inflated, (b) youths at different stages of smoking onset all overestimate smoking prevalence, and (c) the predictors of these estimates are the same for youths at different stages of smoking onset. Measures of smoking behavior based on self-reports using a bogus pipeline procedure, estimates of cigarette smoking prevalence (trying behavior and weekly use), and reports of smoking in significant others were obtained by the same youths when they were in eighth and ninth grades. Results indicated that, taken over all youths, estimates of trying cigarettes were accurate, whereas estimates of weekly use were inflated. When responders were defined by their stage of smoking onset, either as a nonsmoker, trier, or regular smoker, analyses revealed that triers were accurate regarding prevalence estimates of trying, whereas non-smokers made gross underestimations and regular smokers made overestimations of trying. All groups of youths overestimated prevalence of weekly smoking. Analyses of variance revealed that both youths' smoking status and interpersonal smoking environment additively predicted prevalence estimates, and estimates of smoking prevalence were relatively higher in youths who began to smoke, or increased their levels of smoking, within the next year. Thus, previous assumptions were partially confirmed. Future research and prevention programming should focus more on regular smoking as the focus of normative smoking distortion effects and correction efforts.     

A mathematical approach for establishing treatment priorities among patients

Medical decision making often utilizes subjective observations to arrive at concrete judgments. The decisions frequently affect who receives scarce medical treatments and, thus, who lives or dies. In this paper, a model health status index is described. It is specific for the problem of choosing patients for hemodialysis or transplantation. Such a health status index may be designed for any medical decision involving such issues as drug treatment priorities, identification of salvageable patients, and selection of patients for scarce medical treatment. This index (1) incorporates a physician's own medical criteria and values, (2) can be modified as the data base improves, (3) assures consistency from decision to decision, and (4) can be developed and used without the help of a mathematician or computer.     

A computerized method of analyzing and playing back vibratory animal signals

In water striders or other animals that communicate with vibratory or oscillatory signals, surface wave signals can be recorded, analyzed in digital form by computer, then played back accurately by oscillating a magnet, glued to the animal, with electromagnetic fluctuations from a coil driven by the computer. Signals can be played with great flexibility through a normally behaving animal, in laboratory or field.     

Social Status and Prestige in the Selection of a Program of Study in the Community-Junior College

This study examines the relative emphasis placed upon social status and prestige in the selection of an occupation and program of study by students in the community-junior college. The following results were noted: (1) Students enrolled in college transfer programs stressed prestige in the selection of an occupation to a greater extent than did those in technical and semi-professional programs. (2) When the students in the sample were grouped according to occupational aspiration level, a positive correlation was found to exist between occupational aspiration level and prestige emphasis. (3) No significant relationship was found to exist between the social status of students and prestige emphasis in the selection of an occupation.