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Eleven nulliparous women manually self-stimulated to orgasm, each on three separate occasions. Pelvic contraction pressure was measured by an anal probe and a vaginal probe simultaneously. Near the perceived start of orgasm, a series of regular contractions began in nine of the women. Anal and vaginal contraction waveforms were synchronized with each other, and the same number of orgasmic contractions occurred in each lumen. Anal pressure had a higher resting baseline and greater amplitude contractions than vaginal pressure. The perceived start of orgasm did not correspond precisely with the onset of regular contractions. Mean intercontraction intervals increased linearly at an increment of about 0.1 second through the series of regular contractions. Amplitudes of contraction pressure waveforms, representing pelvic muscular force, were initially low, increased through the first half of the regular series, and then decreased. Area and net area of the pressure waveforms, reflecting pelvic muscular exertion (force x time), increased during the regular orgasmic contractions. Three of the women's orgasms consistently included only a series of regular contractions (orgasm type I). For six other women, orgasms consistently continued beyond the regular series with additional irregular contractions (orgasm type II). Types I and II had been identified previously in men. Two women had no regular contractions during reported orgasms. This pattern, type IV, had not been recorded in men. Women of different types showed marked differences in orgasm duration and number of contractions. Identification of these types in subjects is important for meaningful comparison of contraction parameters in different studies.

In spite of a stereotype of male preference for competition and female ipreference for cooperation, many studies of sex differences in cooperative! and competitive behavior and attitudes at different age levels and in different artificial settings have produced inconsistent findings. In this study, attitudinal data from a survey of over 2,400 students in Grades 2-12 were used to depict sex differences in cooperativeness and competitiveness in a natural school setting. Females showed consistently more positive attitudes toward cooperation in school, and males showed consistently more positive attitudes toward competition, with the greatest differences appearing in Grades 8-10. Differences ranged from about .2 to about .9 standard deviation.There is evidence of a sex role stereotype in which males are more competitive and less cooperative than females (Broverman,

Assessment influences every level of the education system and is one of the most crucial catalysts for reform in science curriculum and instruction. Teachers, administrators, and others who choose, assemble, or develop assessments face the difficulty of judging whether tasks are truly aligned with national or state standards and whether they are effective in revealing what students actually know. Project 2061 of the American Association for the Advancement of Science has developed and field-tested a procedure for analyzing curriculum materials, including their assessments, in terms of how well they are likely to contribute to the attainment of benchmarks and standards. With respect to assessment in curriculum materials, this procedure evaluates whether this assessment has the potential to reveal whether students have attained specific ideas in benchmarks and standards and whether information gained from students' responses can be used to inform subsequent instruction. Using this procedure, Project 2061 had produced a database of analytical reports on nine widely used science middle school curriculum materials. The analysis of assessments included in these materials shows that whereas currently available materials devote significant sections in their instruction to ideas included in national standards documents, students are typically not assessed on these ideas. The analysis results described in the report point to strengths and limitations of these widely used assessments and identify a range of good and poor assessment tasks that can shed light on important characteristics of good assessment. ß 2002 John Wiley & Sons, Inc. J Res Sci Teach 39: 889-910, 2002 Assessment of student performance exerts extraordinary influence on the lives of children and their families and on every level of the education system. If used properly, good assessment can be a powerful catalyst for improving both curriculum and instruction. Poor assessment practices, on the other hand, can impoverish our expectations for learning science, focusing teachers' and students' efforts on less important concepts and skills or on test taking as an end in itself.