Productive failure as an instructional approach to promote future learning

Productive failure is an instructional approach that requires learners to struggle as they attempt to generate solutions to problems before, rather than after, receiving direct instruction on a targeted concept. Studies demonstrate that productive failure prepares students for later learning of new, related knowledge. Our study explored the effectiveness of productive failure as an instructional intervention in health professions education with respect to (a) acquisition and application of a novel concept, and (b) learners’ preparation for future learning of new, related content. Forty year-one students enrolled in the Doctor of Pharmacy program at the University of Toronto were randomly assigned to a productive failure (i.e. attempt to generate solutions before receiving instruction) or direct instruction only learning condition. After a practice phase, participants completed a series of tests designed to measure knowledge acquisition, knowledge application, and preparation for future learning (new learning is required for successful problem solving). As expected, no difference in performance was seen between participants on the acquisition and application tests. However, participants in the productive failure condition outperformed those in the direct instruction condition on the preparation for future learning test. These results emphasize the role of struggle in learning and support the theory that engaging students in solving problems that are beyond their abilities can be a productive exercise in failure. The results suggest that productive failure assists learners in acquiring the conceptual knowledge needed to facilitate learning in the future

Assessment of the capacity of vehicle cabin air inlet filters to reduce diesel exhaust-induced symptoms in human volunteers

BACKGROUND: Exposure to particulate matter (PM) air pollution especially derived from traffic is associated with increases in cardiorespiratory morbidity and mortality. In this study, we evaluated the ability of novel vehicle cabin air inlet filters to reduce diesel exhaust (DE)-induced symptoms and markers of inflammation in human subjects. METHODS: Thirty healthy subjects participated in a randomized double-blind controlled crossover study where they were exposed to filtered air, unfiltered DE and DE filtered through two selected particle filters, one with and one without active charcoal. Exposures lasted for one hour. Symptoms were assessed before and during exposures and lung function was measured before and after each exposure, with inflammation assessed in peripheral blood five hours after exposures. In parallel, PM were collected from unfiltered and filtered DE and assessed for their capacity to drive damaging oxidation reactions in a cell-free model, or promote inflammation in A549 cells. RESULTS: The standard particle filter employed in this study reduced PM10 mass concentrations within the exposure chamber by 46%, further reduced to 74% by the inclusion of an active charcoal component. In addition use of the active charcoal filter was associated by a 75% and 50% reduction in NO2 and hydrocarbon concentrations, respectively. As expected, subjects reported more subjective symptoms after exposure to unfiltered DE compared to filtered air, which was significantly reduced by the filter with an active charcoal component. There were no significant changes in lung function after exposures. Similarly diesel exhaust did not elicit significant increases in any of the inflammatory markers examined in the peripheral blood samples 5 hour post-exposure. Whilst the filters reduced chamber particle concentrations, the oxidative activity of the particles themselves, did not change following filtration with either filter. In contrast, diesel exhaust PM passed through the active charcoal combination filter appeared less inflammatory to A549 cells. CONCLUSIONS: A cabin air inlet particle filter including an active charcoal component was highly effective in reducing both DE particulate and gaseous components, with reduced exhaust-induced symptoms in healthy volunteers. These data demonstrate the effectiveness of cabin filters to protect subjects travelling in vehicles from diesel exhaust emissions