The data were analyzed on three levels. First, the recorded
interview parts were content-analyzed line-by-line. This categorized
student’s ideas as scientific or nonscientific. Second, these key ideas
were translated into conceptual models. These snapshots of thinking across interview parts revealed changes over time. Third, a
two-dimensional classification scheme was applied to the conceptual models. One dimension recorded understanding as nonscientific, mixed, or scientific. The other dimension recorded scientific
thinking level as low, medium, high, or advanced. This allowed
me to identify and record changes in students’ scientific thinking
about food webs within and between the interviews influenced by
the diagram. Pooling the data allowed trends in students’ thinking
about food weds to be determined.
Elementary-Level Students’ Reading of a Simple
Food Web Diagram
Excerpts from the interviews are presented using example students
(names are pseudonyms) to show the typical approaches they used
to make sense of the food web diagram. Each example is discussed
briefly to highlight the issues revealed about the diagram and/or the
elements of the students’ thinking that influenced their understanding
Example 1: Arrow Direction
RESEARCHER: What’s happening in this picture?
NORMA: The plant, no the slug, eats, ah [thinking] the slug eats the, and
it’s going [confused expression] because the arrows are pointing
that way it means they have the plants eating the slug.
RESEARCHER: So you think the arrow means, “this is eating that” Ignore
the arrows and tell me what eats what.
NORMA: The snail eats the crops and stuff, the frog eats the snail, and
the kingfisher eats it.
Starting reading from the plant, Norma faltered as she tried to make
sense of the arrows. Norma thought the arrows showed that the plant
“is eating” the slug (snail). That she thought the arrow should point
away from, not toward the slug indicates her lack of knowledge of
conventional arrow meaning in food webs (energy transfer between
Figure 2. Visual diagram replica.
Figure 3. Labeled diagram replica.