204 Kamini Jaipal Jamani
Mrs. Lowe wanted to ―open up students‘ minds in science to new ideas and concepts and
[show students] how to approach them in a scientific way – to look for evidence, to question‖
and to see science in the context of society. She engaged students in thinking about scientific
ideas through visual, verbal, written, and action representations. Her personal beliefs about
the nature of science (epistemological aspect) were supported by her sequencing of multiple
modalities. A historical video (visual mode - A) about the changes in ideas about motion from
Aristotle to Newton communicates the evidence-based nature of science, the changing nature
of scientific beliefs over time, and the religious, social and political influences on the
construction of scientific knowledge. These epistemological aspects, particularly the nature of
scientific knowledge as changing over time and involving reasoning processes such as
abduction, are reinforced by explicit written questions such as ―Describe Galileo‘s thought
experiment that led to the idea of inertia?‖ and ―How did Newton change Galileo‘s Law of
Inertia?‖ (mode B). Besides communicating the nature of science through historical
examples, the video also provides representations of cases of inertia and introduces the
conceptual meaning of inertia. Further analysis of the organization of the questions suggests
that the sequencing of questions supports the development of the conceptual meaning of
inertia. The order of questions shows the progressive historical development of inertia.
Additionally, in the question ―What type of motion did Galileo think continued unless it was
interrupted?‖ the use of the word ―unless‖ introduces the notion of a cause-effect relationship
and signals the idea of a force. Another feature of the questions is the language used -
academic and formal terms (e.g., proposed, motion) signal science as a formal body of
knowledge that is different from everyday explanations.
Consistent with Mrs. Lowe‘s belief of looking for evidence, the use of a demonstration
and a hands-on experiment (action modalities C and D) signal the nature of science as
experiential and evidence-based and reinforce the epistemological aspect of meaning.
However, these action representations, involving the movement of a ball on a dynamics cart,
simultaneously communicate the conceptual meaning of inertia as an object at rest and in
uniform motion. In this case, concrete and visual representations of the abstract concept
̳inertia‘ reinforce and extend observations from the video. A worksheet, accompanying the
hands-on activity, serves to organize the development of the concept of ̳inertia‘ and the
derivation of Newton‘s First Law. Step-by step procedures on the worksheet - organizational
aspect of meaning - contribute to the conceptual aspect of meaning.
Once the First Law has been generalized from observation and experiment, the use of
everyday applications such as the seat belt scenarios (mode E) position scientific knowledge
within everyday phenomena and minimizes the gap between scientific knowledge and
everyday explanations (social aspect). The use of the personal pronoun ―you‖ in the scenario
questions supports the social aspect of meaning by situating the student within the
phenomena, thereby personalizing scientific knowledge. Force diagrams, the final mode (F),
signal another feature contributing to the conceptual meaning of ̳inertia‘ – the specific forces,
their direction, and how they interact with each other. The word ―draw‖ and ―show‖ indicate
the type of organizational aspects (pictures and lines of force) required to communicate the
conceptual meaning of inertia on a diagram. Drawing on students‘ personal, everyday
experience to draw a force diagram once again suggests that scientific knowledge is
represented as accessible (social meaning) and portrayed as an integral part of everyday
phenomena (epistemological meaning).