Encourage your students to utilize hand gestures to enhance their comprehension of challenging chemistry concepts. Visuospatial thinking is recognized as a crucial cognitive aspect of problem-solving in scientific education. Spatial ability encompasses the capacity to mentally manipulate, rotate, and transform imagined images. These mental visualization skills and imagistic reasoning are essential for grasping science concepts at more advanced levels.
Studies have demonstrated that problem solvers utilize imagistic reasoning, in addition to analytical thinking, to solve complex problems. Gestures serve as a crucial representational mode in this process. Hand gestures, specifically, aid in conveying relational, spatial, and embodied concepts effectively.
Research indicates that novice students frequently employ imagistic strategies to visualize molecular structures when transitioning between 2D and 3D representations. Post-16 students typically encounter this challenge for the first time when learning about Valence Shell Electron Pair Repulsion (VSEPR) theory, which offers an algorithmic approach to predicting the 3D shape of various molecules.
Visuospatial Thinking
A study investigated the role of visuospatial thinking in aiding students in mastering molecular geometry. Researchers devised an open-ended written activity to assess various aspects of student reasoning, involving 16 participants. Over an 80-minute double period, students were tasked with describing their comprehension of the 3D shapes of molecules.
The lesson began with a 20-minute lecture on VSEPR using PowerPoint slides, followed by an eight-question written exercise. Students, working in pairs, filmed each other while predicting the molecular geometries of selected compounds. They had 30 minutes to complete the task and were familiar with the video-recording method. Notably, all 3D molecular models were kept out of their view during this process.
During the analysis of the video data, researchers identified instances of gesturing, totalling 440 gestures observed across the group. Here’s an example of how the data was interpreted:
“Imagine that the central atom is here” (left fist clenched to represent the central atom), “then the hydrogens go here” (pointing with the right hand to space around the fist), “here” (pointing to a different space around the fist), and “here” (pointing to a third location around the fist).
Interestingly, students relied more on imagistic reasoning when dealing with molecules containing fewer than five atoms and those with lone pairs.
The researchers categorized five distinct types of gestures:
Beat: Consists of repeatedly raising both hands up and down while stating “because the lone pairs repulse more.”
Deitic-beat: Involves repeatedly pointing with hands to emphasize speech delivery rather than convey imagistic information.
Deitic: Involves pointing at four imaginary points in space while stating: “you’ve got an N at the top and three Hs here, here, and here.”
Deitic-iconic: Utilizes two-handed gestures where one hand depicts an iconic representation, such as a trigonal pyramidal shape, while the other hand points to locations on the first hand to indicate atom positions.
Iconic: Utilizes one- or two-handed gestures representing a molecular shape.
In essence, the results aligned with prior research indicating that novice learners typically lean on imagistic reasoning methods when initially introduced to a subject, before gradually adopting alternative analytical approaches. Experts, on the other hand, have already internalized analytical techniques over time to guide their problem-solving. Remarkably, in this study, students possessed this scaffolding from the outset, yet a significant portion continued to rely on imagistic strategies.
