Royalties, evolving patent rights, and the value of innovation

The value of an innovation to the innovator can change over time, especially in response to changes in the legal protection (such as patent rights) afforded the innovator. A proven-valid-and-infringed patent is a more valuable economic commodity than is an untested patent. The increase in value can be estimated using the success rate of patent lawsuits. Using a database of the outcomes of U.S. patent litigation, we find that plaintiffs win patent litigation some 45% of the time at the trial court level. This has implications both for patent damages awards and for the incentives to innovate.     

Behavior of Infants with Iron-Deficiency Anemia

This study tested the hypothesis that infants with iron-deficiency anemia show behaviors, such as increased proximity to caregivers, increased wariness or hesitance, and decreased activity, that could contribute to “functional isolation.” The behavior of 52 Costa Rican 12- to 23-month-old infants with iron-deficiency anemia was contrasted with that of 139 comparison group infants with better iron status during free play and mental and motor testing and in the home. Infants with iron-deficiency anemia maintained closer contact with caregivers; showed less pleasure and delight; were more wary, hesitant, and easily tired; made fewer attempts at test items; were less attentive to instructions and demonstrations; and were less playful. Adult behavior also differed. The results indicate that iron-deficiency anemia in infancy is associated with alterations in affect and activity, suggesting that functional isolation is a useful framework for understanding poorer developmental outcome in iron-deficiency anemia, the world's most common single nutrient deficiency.     

Note on Sources of Sampling Variability in Science Performance Assessments

In 1993, we reported in Journal of Educational Measurement that task-sampling variability was the Achilles' heel of science performance assessment. To reduce measurement error, tasks needed to be stratified before sampling, sampled in large number, or possibly both. However, Cronbach, Linn, Brennan, & Haertel (1997) pointed out that a task-sampling interpretation of a large person x task variance component might be incorrect. Task and occasion sampling are confounded because tasks are typically given on only a single occasion. The person x task source of measurement error is then confounded with the pt x occasion source. If pto variability accounts for a substantial part of the commonly observed pt interaction, stratifying tasks into homogenous subsets—a cost-effective way of addressing task sampling variability—might not increase accuracy. Stratification would not address the pro source of error. Another conclusion reported in JEM was that only direct observation (DO) and notebook (NB) methods of collecting performance assessment data were exchangeable; computer simulation, short-answer, and multiple-choice methods were not. However, if Cronbach et al. were right, our exchangeability conclusion might be incorrect. After re-examining and re-analyzing data, we found support for Conbach et al. We concluded that large task-sampling variability was due to both the person x task interaction and person x task x occasion interaction. Moreover, we found that direct observation, notebook and computer simulation methods were equally exchangeable, but their exchangeability was limited by the volatility of student performances across tasks and occasions.     

Re/presenting a gender equity project: Contrasting visions and versions

This article provides three different accounts of a gender-equity project in a Grade 10 science class. The three stories, a realist one of victory over oppression, a realist story of inclusion, and a reflexive story of identity, illustrate different rhetorical forms for representing research and different assumptions about gender, pedagogy, equity, and the representation of data. Any version of a project can only be a partial account. As teachers and researchers, our commitments and investments influence our questions, understandings, and representations. The content and form of our stories imply particular relationships with an audience. Those responsible for policy tend to favor realist stories that reduce complexity and increase certainty. Others may be more interested in stories that portray complexity and highlight the need for judgments in particular contexts. No one form is appropriate for all occasions. © 1998 John Wiley & Sons, Inc. J Res Sci Teach 35: 859–876, 1998.     

Cognitive assessment of function knowledge

Two theories of assessing function knowledge were compared for intuitive physics. The choice assessment theory, derived from Piaget, presents subjects with two physical situations, each specified by the values of two physical variables; subjects choose the situation which will yield the greater value of a dependent variable. Functional measurement presents subjects with a single physical situation; subjects make a quantitative estimate of the dependent variable. Forty subjects made both choice and functional measurement responses for two situations of intuitive physics. The choice theory showed substantial frequencies of stepwise rules, implying that subjects failed to integrate the two given physical variables. Functional measurement, in contrast, showed that most subjects integrated the two variables, following exact addition or multiplication rules. It is concluded that functional measurement gives a more correct assessment of function knowledge and should be useful in science instruction. J Res Sci Teach 34: 359–376, 1997.     

IQ and neuropsychological predictors of academic achievement

Word reading and math computation scores were predicted from Wechsler Abbreviated Scale of Intelligence Full Scale IQ, 10 neuropsychological tests, and parent attention deficit hyperactivity disorder (ADHD) ratings in 214 general population elementary school children. IQ was the best single predictor of achievement. In addition, Digit Span contributed significantly to reading prediction, and the Developmental Test of Visual-Motor Integration (VMI) and Coding contributed to math prediction. The remaining neuropsychological test scores did not significantly improve achievement prediction. Exploratory factor analysis yielded a general ability factor (comprising the four IQ subtests, Digit Span, VMI, reading, and math), five factors made up solely of subtests from single measures (Wisconsin Card Sorting Test, Stroop Color and Word Test, Gordon Diagnostic System, California Verbal Learning Test, and ADHD ratings), a factor consisting of Grooved Pegboard Test and Coding, and a factor consisting of Symbol Search and Animal Naming Test.