The effect of incorporating youtube videos into an intervention addressing students' misconceptions related to solutions, solubility, and saturation

Students in introductory chemistry classes often harbor or develop misconceptions about solution concepts related to solubility, saturation, and supersaturation. They bring these misconceptions into introductory materials classes and are unable to understand fundamental phase diagram concepts. As such, they are unable to appreciate the relationships between phase diagrams, heat treatments, materials' microstructures and associated materials' properties. The most common misconception about solutions and solubility for liquid and solid phases is that a supersaturated solution contains both liquid and solid phases instead of a supersaturated solution containing excess solute in concentration above equilibrium. The diagnosis of this and other misconceptions creates the possibility of devising interventions to address the misconceptions. When interventions in previous materials science courses were given, it resulted in only modest gains in students' understanding of solution and solubility concepts. In this paper we are posing the research question of, "What is the effect of incorporating YouTube videos into an intervention that addresses student misconceptions on solution and solubility concepts?" A concept pretest was given before the intervention and phase diagram instruction and a concept posttest was given after phase diagram instruction was completed. The concept test consisted of three beakers of water with varying amounts of sugar in each solution as indicated by density of dots in the beaker. The unsaturated solution showed a low density of dots. The saturated solution showed a moderate density of dots and with a small mound of saturated sugar at the bottom of the beaker. The supersaturated solution had a high density of dots that represented excess solute in solution beyond the equilibrium solubility limit. Students were told to choose the correct label (unsaturated, saturated, or supersaturated) for each beaker and give the reasoning for their choice. Four different interventions were tested between 2007 and 2013. The 2007 intervention involved explicit discussion and identification of solubility limit lines and associated single and two-phase regions of a eutectic phase diagram. It resulted in an average Hake gain of 26%. The 2011 intervention involved a student graphing activity and resulted in an average Hake gain of 26%. The 2012 intervention was an engagement activity that had visual representations of the various conditions of supersaturated, saturated, and unsaturated solutions that changed with differing conditions. The 2012 intervention had a significantly greater average Hake gain of 49%. This 2013 study used the visual student engagement activity from the 2012 intervention but supplemented it with a YouTube video demonstration of a rapid precipitation of a heavily supersaturated solution. The 2013 study resulted in an average Hake gain of 65%, with the largest average Hake gain improvement of the four studies. The results from this study show promise that student engagement activities supplemented with YouTube or other video demonstrations can an effective means of repairing students' misconceptions on solution and solubility concepts. This type of intervention has potential to be applied to other misconceptions as well. The efficacy of 2013 intervention will be tested for reproducibility in the Spring 2014 materials class and results will be presented at the conference.