Recent progress in the plastic methods of structural analysis

The techniques described in Part I of this paper for the calculation of plastic failure loads under proportional loading are further exemplified by indicating solutions for a rectangular building frame, a Vierendeel girder, and a shed-type portal frame. A method for estimating deflections of a frame just as the collapse load is attained is then described, with some indications as to its reliability. More general conditions of loading than proportional loading are next discussed, and generalized load and failure concepts are defined. The theorems and techniques for determining critical shakedown loads under variable, repeated loading are then described and illustrated. The relation of the elastic-plastic shakedown analysis to the much simpler analysis for failure under single load applications is discussed.     

Formative Assessment: A Meta‐Analysis and a Call for Research

An effect size of about .70 (or .40–.70) is often claimed for the efficacy of formative assessment, but is not supported by the existing research base. More than 300 studies that appeared to address the efficacy of formative assessment in grades K‐12 were reviewed. Many of the studies had severely flawed research designs yielding uninterpretable results. Only 13 of the studies provided sufficient information to calculate relevant effect sizes. A total of 42 independent effect sizes were available. The median observed effect size was .25. Using a random effects model, a weighted mean effect size of .20 was calculated. Moderator analyses suggested that formative assessment might be more effective in English language arts (ELA) than in mathematics or science, with estimated effect sizes of .32, .17, and .09, respectively. Two types of implementation of formative assessment, one based on professional development and the other on the use of computer‐based formative systems, appeared to be more effective than other approaches, yielding mean effect size of .30 and .28, respectively. Given the wide use and potential efficacy of good formative assessment practices, the paucity of the current research base is problematic. A call for more high‐quality studies is issued.     

Infant joint attention, temperament, and social competence in preschool children

Infant joint attention has been observed to be related to social-emotional outcomes in at-risk children. To address whether this relation is also evident in typically developing children, 52 children were tested at 12, 15, 24, and 30 months to examine associations between infant joint attention and social outcomes. Twelve-month initiating and responding to joint attention were related to 30-month social competence and externalizing behavior, even when accounting for 15-month temperament ratings, 24-month cognition and language, and demographic variables. These results suggest that, in addition to associations with language and cognition, infant joint attention reflects robust aspects of development that are related to individual differences in the emergence of social and behavioral competence in childhood.     

How Do Academic Achievement and Gender Affect the Earnings of STEM Majors? A Propensity Score Matching Approach

The United States government recently enacted a number of policies designed to increase the number of American born students graduating with degrees in science, technology, engineering and mathematics (STEM), especially among women and racial and ethnic minorities. This study examines how the earnings benefits of choosing a STEM major vary both by gender and across the distribution of academic achievement. I account for the selection into college major using propensity score matching. Measures of individual educational preferences based on Holland’s theory of career and educational choice provide a unique way to control for college major selection. Findings indicate that the earnings benefit to STEM major choice ranges from 5 to 28 % depending both on academic achievement and on gender and that high-achieving students benefit more from STEM major choice. Further, high achieving men benefit more from STEM majors than high-achieving women. Earnings differences in major choice may play an important role in explaining the underrepresentation of women in STEM major fields, especially among high achieving students.