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Measuring and Reducing Chemical Spills by Students: A Randomized Controlled Trial of Providing Feedback
journal contribution
posted on 2019-08-19, 14:34 authored by Aimilia M. Tsokou, Alix Howells, Moray S. StarkThe ability to handle chemicals safely
is a key aspect of the learning
development of students studying chemistry; however, there have been
no previously reported investigations of the quantity of chemicals
spilled by students during lab experiments. Therefore, the first part
of this article reports the assessment of the volume of chemicals
spilled by year 1 undergraduate chemistry students (n = 64) at a U.K. university during an existing chemical analysis
practical designed to develop volumetric handling skills. The experiment
was carried out on paper liners, allowing the areas of students’
spills to be visible and quantified using calibrated spill volumes
of liquid to determine the resultant spill area. The volume spilled
by the student group was ca. 1.2% of that handled; however, the amount
spilled by individual students ranged widely, from ca. 0.02% to ca.
10% of the volume handled. A feedback tool has been developed to allow
laboratory demonstrators to rapidly quantify chemical spillage by
individual students. This tool also provides the demonstrators with
a framework to communicate the potential safety significance of the
volume of chemical a student has spilled. A randomized controlled
trial (RCT) was carried out to examine the effect of providing feedback
to students on their chemical spillage during a subsequent experiment.
From a cohort of 185 year 1 undergraduate students, 150 consented
to be randomized (81%), and data was collected for 144 students (96%
of those randomized). A Hodges–Lehmann estimator for the median
change in volume spilled during the second experiment due to providing
feedback on spillage during first experiment was a 50% decrease in
volume spilled (95% confidence range: 0 to 80% decrease, Mann–Whitney U test p = 0.05). The RCT was a waiting
list trial, with all student receiving feedback either during or after
the RCT, with blinded assessment by the demonstrators assessing volume
spilled for the RCT.