Error Patterns in the Prediction of Fertility Behavior1

Two separate three-wave, 2-year, longitudinal studies investigated error patterns in two decision models' predictions of couples' birth-planning decisions. One study tested the subjective expected utility model with a sample of married couples from the state of Washington and the other study tested the Fishbein model using a sample of married women from Illinois. Consistent with the proposal that predictions of deviation from the status quo result in a higher proportion of prediction errors than predictions of nondeviation from the status quo, both studies demonstrated that when couples were predicted to decide not to become pregnant, predictive accuracy was very high, but when couples were predicted to decide to become pregnant, predictive accuracy was significantly lower. Two hypothesized explanations for the biased error pattern were considered and received some support. The first, resembling the concept of inertia, is that a stronger motivational force is required to compel a person to elect a change from the status quo than is required to maintain the status quo. The second focuses on changes in decisions as a function of time and events. The heuristic value of directly examining prediction errors, in contrast to the more prevalent practice of reporting only one summary index of goodness of fit, was discussed.     

Percentage points of Wilks'L mvc andL vc criteria

Likelihood ratio tests have been proposed by Wilks for testing the hypothesis of equal means, variances, and covariances (H _mvc) and the hypothesis of equal variances and covariances (H _vc) in ap-variate normal distribution. Using exact distributions of the appropriate likelihood ratio statistics, tables of the .05 and .01 points of these distributions are constructed forp = 4, 5, 6, 7 and sample sizen = 25 (5) 60 (10) 100. A correction factor is recommended for largern. Two numerical examples illustrate use of the tables. A nonparametric test is proposed forH _mvc when the multivariate parent population is known to be non-normal.This research was supported partly by the Office of Naval Research under Contract No. Nonr-855(06) and partly by the United States Air Force through the Air Force Office of Scientific Research of the Air Research and Development Command, under Contract No. 18(600)-83. Reproduction in whole or in part for any purpose of the United States Government is permitted.     

Projector slide changing and focusing as operant reinforcers

Uninstructed subjects choose to view, in sharp focus where possible, projected visual images in preference to various simpler auditory and visual stimuli (e.g., buzzers of flashing lights). The rate of responding on the lever rapidly increased above the operant level (projector inoperative) even though the stimuli were nonsense syllables. When focusing also was made contingent on responses, the subjects promptly started sharpening the focus of legible but blurred nonsense syllables. When the visual material was colored landscape scenes, the rates of slide-changing generally decreased, because of increased viewing time relative to the nonsense syllables, at the same time that the latencies of focusing decreased. Both the sharpness of focus and the total time spent with the image in sharp focus increased greatly with the colored slides, establishing that the subjects were under control of the stimulus events. Extinction of both responses occurred very rapidly when the controls became inoperative.     

Object relocation: a program for setting up, running, and analyzing experiments on memory for object locations

Object Relocation is a computer program for Windows 95, with which experiments on spatial memory for object locations can be designed, run, and analyzed. Because of its clear graphical user interface, no long and complex command syntax is needed. Basically, a stimulus consists of a frame that contains a chosen number of locations (i.e., the actual spatial layout) to which objects can be assigned. When the experiment is run, these stimuli are presented to the subject for a variable period of time. Subsequently (either with or without a delay), the objects are presented in a row above the frame and have to be relocated to the correct positions. Finally, the raw data can be analyzed efficiently, using various error scores, and an SPSS-ready output file can be produced. Object Relocation is a very flexible program: New objects and positions can easily be added, and various options for presentation and relocation are present.     

Students' perceptions of male sexually aggressive behavior as a function of educational level and gender

Two hundred and four students (108 college freshmen, sophomores, juniors, and seniors; 96 high school juniors and seniors) participated in this study. The socioeconomic status of the participants (high school = 93% Caucasian, 7% African-American; college = 96% Caucasian, 4% African-American) was primarily in the lower middle-class range. The purposes of this investigation were (1) to test whether or not differences exist between high school and college students' perceptions of one form of male sexually aggressive behavior against women, (2) to determine if differences exist between male and female students' perceptions of such behavior against women, and (3) to explore the sex role socialization theory by providing empirical observation of its basic tenets. Findings suggested that boys may experience slower maturation and development of sensitivity toward sexual aggression than girls, but that this gap may lessen with advancing age for college males.     

A translation-based generation effect in bilingual recall and recognition

Two experiments were performed with incidental study procedures in which generation effects were observed for relatively balanced French-English bilingual subjects on measures of both free recall and recognition. Experiment 1 used a within-subject design, and Experiment 2 used a between-subject design. In both experiments, reading translations and reading same-language repetitions generally resulted in similar amounts of retention. Experiment 2 and Experiment 3 also showed that the generation effect was abolished under intentional study procedures because of an enhancement of reading-based retention. The results suggested that previous failures to obtain a translation-based generation effect may have been due to the use of intentional study procedures. The pattern of effects was explained in terms of a single-code model of bilingual linguistic representation and an individual-item processing intetpretation of the generation effect.