Affording Design, Affording Redesign - Principia Designae: Pre-Design, Design, and Post-Design - page 90

7.2.4 More Than Nodes and Links
Nodes and links do not exhaust what sketches do and can do. As noted, sketches add
language, where depictions won't do. Sketches add icons for objects, buildings, and
the like. Sketches add a range of schematic graphical forms, lines are one, but that
group also includes arrows, boxes, blobs, brackets, boxes, and more. These espe-
cially have meanings that are readily interpreted in context from their geometric or
gestalt properties (Tversky et al. 2000 ). Lines connect, indicating relations; arrows
are asymmetric lines, indicating asymmetric relations. Boxes contain and separate.
Blobs are vague shapes, indicating 2- or 3-D objects that make take more definite
shape. Because these schematic forms readily take on meanings that vary with
context, they are useful and used across a broad range of sketches and diagrams.
7.2.5 Sketches Consolidate Learning
As noted, sketching provides a natural way to represent a set of organized thoughts
and relations among thoughts. This is a fortiori the case for thoughts and relations
that have physical counterparts, like instructions to operate or assemble something
or explanations of how something is structured or behaves. Although teaching of
these myriad sets of ideas is often accompanied by diagrams and sketches, learning
is typically assessed verbally. The correspondence of meaning to words and
sentences is purely symbolic. There are many benefits to using sketches and dia-
grams in teaching; there should be comparable benefits to students in learning. We
set out to see if that is true (Bobek and Tversky 2014 ) . In two studies in actual
classrooms, junior high students were taught a STEM system, in one case, a bicycle
pump from interaction with a pump, and in the other case, chemical bonding from a
multi-modal video. After learning, students in the chemical bonding lesson were
tested, though students in the bicycle pump condition were not. Then students were
divided into two groups. Half were asked to provide traditional verbal explanations
of the phenomena and half were asked to provide visual explanations. The expla-
nations were coded for the information expressed, especially information about
structure and behavior, process, causality. In general, more of that information
appeared in the visual explanations, some of that in the words and symbols that
accompanied the visual explanations. After completing the explanations, students
were again tested. Note that no additional learning took place after the original
lesson. For the bicycle pump, students of low spatial ability who produced visual
explanations outperformed those who produced verbal ones. This is a simple
device, so it is not surprising that there were no differences in the students of
high spatial ability. In the more complex case of chemical bonding, all students
performed better after creating explanations then immediately after learning, so the
simple act of explaining without new study or information augments learning.
And students of all ability levels performed better after creating visual explanations
than after creating verbal ones. Their sketched diagrams differed widely, some even