In a 1984 essay, Benjamin Bloom, an educational psychologist at the University of Chicago, asserted that tutoring offered "the best learning conditions we can devise" and that tutors could raise student achievement by two full standard deviations--or, in statistical parlance, two "sigmas." The influence of Bloom's two-sigma…

Recent years have seen a dramatic increase in our understanding of the social behaviour of microbes. Here, we take advantage of these developments to present an undergraduate laboratory exercise that uses the cooperative flocculating behaviour of yeast ("Saccharomyces sp.") to introduce the concept of inclusive fitness and teach the…

This paper reviews the use of multiple trials, defined as multiple sites or multiple arms in a single evaluation and replications, in evaluating social programs. After defining key terms, the paper discusses the rationales for conducting multiple trials, which include increasing sample size to increase statistical power; identifying the most…

Improving the interest of high-school students towards chemistry (and science in general) is one of the goals of the Italian Ministry of Education. To this aim, we designed a context-based activity that actively involved students in six different laboratory experiences interconnected by a case study of the murder of Miss Scarlet, from the famous…

We use analogies to provide introductory laboratory students intuition into measurement uncertainties. Using a battery-resistor circuit we discuss uncertainty concepts and derive expressions for uncertainty of the mean and sums of uncertainties. Finally, we draw attention to the fact that the interpretation of standard deviation as uncertainty…

With a view to enhancing the entrepreneurial activity of universities, the authors explore the concepts and features of the "experimental lab", presenting it as an effective means of supporting entrepreneurial training programmes and helping students to turn ideas into actual start-ups. In this context, the term experimental lab refers…

Field experiments in education frequently assign entire groups such as schools to treatment or control conditions. These experiments incorporate sometimes a longitudinal component where for example students are followed over time to assess differences in the average rate of linear change, or rate of acceleration. In this study, we provide methods…

The purpose of this paper is to review and critique a groundbreaking research report. The research article under review in this paper is: "A Big Apple for Educators: New York City's Experiment with Schoolwide Performance Bonuses: Final Evaluation Report" (see ED521920). In 2007-08, a program called the Schoolwide Performance Bonus…

Thermodynamic spontaneity-equilibrium criteria require that in a single-reaction system, reactions in either the forward or reverse direction at equilibrium be nonspontaneous. Conversely, the concept of dynamic equilibrium holds that forward and reverse reactions both occur at equal rates at equilibrium to the extent allowed by kinetic…

This meta-analysis provides an extensive and organized summary of intervention studies in education that are grounded in motivation theory. We identified 74 published and unpublished papers that experimentally manipulated an independent variable and measured an authentic educational outcome within an ecologically valid educational context. Our…

The main result of an experiment is typically an estimate of the average treatment effect (ATE) and its standard error. In most experiments, the number of covariates that may be moderators is large. One way this issue is typically skirted is by interpreting the ATE as the average effect for "some" population. Cornfield and Tukey (1956)…

Experimental evaluations that involve the educational system usually involve a hierarchical structure (students are nested within classrooms that are nested within schools, etc.). Concerns about contamination, where research subjects receive certain features of an intervention intended for subjects in a different experimental group, have often led…

How effective is training frogs to jump? This is perhaps the most frequent question in biology that is subjected to statistical analysis: does a treatment make a difference? One can examine whether there is indeed a training effect, by first assuming the opposite. That is, the authors assume that training has no effect on the mean distance jumped.…

Cognitive control enables flexible interaction with a dynamic environment. In 2 experiments, the authors investigated control adjustments in the stop-signal paradigm, a procedure that requires balancing speed (going) and caution (stopping) in a dual-task environment. Focusing on the slowing of go reaction times after stop signals, the authors…

Any set of confidence interval inferences on J - 1 linearly independent contrasts on J means, such as the two comparisons [mu][subscript 1] - [mu][subscript 2] and [mu][subscript 2] - [mu][subscript 3] on 3 means, provides a basis for the deduction of interval inferences on all other contrasts, such as the redundant comparison [mu][subscript 1] -…