Our paper is an analytical review of the design, development and reporting of learning progressions and teaching sequences. Research questions are: (1) what criteria are being used to propose a "hypothetical learning progression/trajectory" and (2) what measurements/evidence are being used to empirically define and refine a "hypothetical learning…

Cost-effective, easily replicated program is a win-win situation for high schoolers who teach science and for their elementary students. The thank-you letter from Leslie, a grade-schooler in San Diego County's Ramona Unified School District, speaks volumes about the excitement generated by "Celebrate Science"--an innovative,…

A hands-on, minds-on inquiry chemistry experiment was developed for use in K-12 schools that enables students to combine the chemicals of their choice and observe the results. The chemistry involved is water based and builds upon acid-base, double displacement, and iodometric detection of starch reactions. Chemicals readily available in the…

The dominant PDS models described in research literature are all based upon the pairing of traditional, college-based teacher education programs with traditional public schools. Though these PDS models have proven very successful in such contexts, there is significant question as to whether they can be successful when comprised of nontraditional…

The Measures of Effective Teaching project has collected performance data using multiple indicators from over three thousand teachers across six urban districts. In the second year of the study, classes of students were randomly assigned to teachers in order to assess the impact of assignment bias on performance judgments. This article discusses…

One of the main tenets of the mental model theory is that when individuals reason, they think about possibilities. According to this theory, reasoning on what is possible from the truth of a sentence would be psychologically basic, whereas reasoning the other way round, on the truth or falsity of a sentence from a given state of affairs, would…

Intelligent tutoring systems (ITS) support students in learning a complex problem-solving skill. One feature that makes an ITS architecturally complex, and hard to build, is support for strategy freedom, that is, the ability to let students pursue multiple solution strategies within a given problem. But does greater freedom mean that students…

To conceive the infinity of integers, one has to realize: (a) the unending possibility of increasing/decreasing numbers (potential infinity), (b) that the cardinality of the set of numbers is greater than that of any finite set (actual infinity), and (c) that the leap from a finite to an infinite set is itself infinite (immeasurable gap). Three…

One of the major story lines of the growth of civilization is the advance of the experiment. From the food we eat to the diseases we conquer to our understanding of how we think and behave, we have profited enormously from an approach that marries our models of the world with tests of their validity through systematic variation to determine cause…

Biological evolution still lacks representation in school, especially below high school level. In order to find new implications that could help achieve significant improvement in teaching evolution, twelve expert interviews with both renowned researchers and experienced science teachers were conducted. Results of the comparison between the…

The uneven distribution of knowledge within modern societies requires a reliance on sources (e.g., reference books, teachers, the Internet) in addition to own experience. Most scientific issues are far too complex to be understood in any depth by laypersons. Successful knowledge acquisition comprises the ability to vary the amount of sources used…

According to Klahr's (2000, 2005; Klahr & Dunbar, 1988) Scientific Discovery as Dual Search model, inquiry processes require three cognitive components: hypothesis generation, experimentation, and evidence evaluation. The aim of the present study was to investigate (a) when the ability to evaluate perfect covariation, imperfect covariation,…

Purpose: This article provides a comprehensive narrative review of intervention studies for children with speech sound disorders (SSD). Its companion paper (Baker & McLeod, 2011) provides a tutorial and clinical example of how speech-language pathologists (SLPs) can engage in evidence-based practice (EBP) for this clinical population. Method:…

Two experiments aim at describing the impact of friendship during a synchronous collaborative information retrieval (SCIR) with young pupils (recruited in Grade 3). In the first study, 68 pupils were asked to look for 13 answers in one of the three following conditions: on an individual basis (condition "Single"), as part of a designed duo with…

The purpose of the study was to update previous meta-analytic findings on the effectiveness of using similarities and differences as an instructional strategy. The strategy includes facilitating student comparison, classification, use of analogies, and use of metaphors. Previously, Marzano, Pickering, and Pollock reported a mean effect size of…