Hands-on science. It's what I want for my students. The science curriculum at the classical elementary school where I teach integrates a hands-on experiment into every lesson. I appreciate it, but had noticed the difficulties middle-school-aged students had when I asked them to read and follow the numbered directions more independently. At the time, I had various ideas about reasons why it was happening and a possible adjustment or two to make for a smoother process the next time. Two articles in the November 2019 issue of the Journal of Chemical Education brought new insights: Design and Evaluation of Integrated Instructions in Secondary-Level Chemistry Practical Work by David J. Paterson and Teaching Laboratories at a Slower Pace: Introduction of Photocomics as Easy-to-Use Laboratory Instruction by Michaela Zeiner, Petra Viehauser, and Christina Steiner-Friedmann (both available to JCE subscribers, or ACS or AACT members)*.
In his introduction, Paterson makes the case for a change in how to present laboratory instructions to students:
"There are several reasons practical work can be ineffective. Johnstone and Wham identified the high probability of students' working memories becoming overloaded. Students must pay attention to many factors, including dealing with apparatus, following written and verbal instructions, recalling and using skills and theory, and attending to the data from the experiment."
"Many of the factors identified by Johnstone and others that lead to information overload can be categorized as extraneous load (i.e., information that students must attend to that do not help with their developing understanding). How practical instructions are presented affects a student's extraneous load."
"The ability of students to effectively visualize what they need to do from a set of written instructions may additionally be hindered by levels of cognitive development. Many students, even at age 16, have not progressed to the Piagetian formal operational stage, where they can deal with more abstract concepts. The use of diagrams integrating pictorial representations of experimental apparatus and simple written instructions may help these students by providing a more concrete basis to work from."
Yes. All those factors were in my classroom.
Both articles present possible options for redesigning laboratory instructions to help reduce the overload. Zeiner et al. use photocomics that combine text with digital photographs. The teachers took digital photographs while performing the lab themselves, then placed them into PowerPoint slide presentation software. They used text boxes on each slide to add relevant text. Students could then either see the instructions on their phones or on printed posters in the lab. Paterson used diagrams (rather than photographs) with text, plus other features such as numbered instructions, arrows to show where to go next, and check-boxes so students could mark completed steps. An instructor might find a particular experiment lends itself more to one of the options, such as if the physical set up would be difficult to diagram rather than photograph. Even the addition of a few photographs to my curriculum would go a long way—the articles made me realize that my school's curriculum uses very few diagrams or photographs in connection with the labs.
Both articles mention benefits of students being able to work more independently, with less waste of both time and materials. Paterson also shares that "an additional benefit may be gained by those with weaker literacy skills or those studying in a non-native language." The time it takes for the redesign of instructions for at least some of the labs could pay off, particularly for labs that have trickier setups or other stumbling blocks for students.
More from the November 2019 Issue
Mary Saecker's JCE 96.11 November 2019 Issue Highlights took me down a chemistry rabbit hole. I always want to see what she's dug up from the JCE resources. This month, in the "From the Archive," I recognized a graphic of infrared images from an article that I wrote about a while ago. Similar images have cropped up lately on social media. I dug a bit myself and reread Summer Camps, an Especially for High School Teachers column that Laura Slocum and I penned over eight years ago. I wrote, "Xie's article 'Visualizing Chemistry with Infrared Imaging' describes the use of infrared (IR) cameras for inquiry-based experiments. The cost is still somewhat prohibitive (~$1,500–2,500), but Xie states that the price continues to drop." The price has definitely dropped since that time. That looped me back around to an article from the October 2019 issue, Exploring Thermal Effects and Behaviors of Chemical Substances Using an Infrared Camera and its graphic. Hunting on Twitter was next. I remembered seeing thermal imaging graphics recently. A search turned up an article about a surprising benefit of a thermal imaging camera at a tourist attraction. As I said, a rabbit hole.
Planning and carrying out investigations in 9-12 builds on K-8 experiences and progresses to include investigations that provide evidence for and test conceptual, mathematical, physical, and empirical models.
Planning and carrying out investigations in 9-12 builds on K-8 experiences and progresses to include investigations that provide evidence for and test conceptual, mathematical, physical, and empirical models. Plan and conduct an investigation individually and collaboratively to produce data to serve as the basis for evidence, and in the design: decide on types, how much, and accuracy of data needed to produce reliable measurements and consider limitations on the precision of the data (e.g., number of trials, cost, risk, time), and refine the design accordingly.