Fig. 12
Graphical representation of attribute relations. The graph was created by a water quality specialist specifically for a junior high school lesson. During the lesson, students visited a nearby river and surveyed its bio-indicators and EC to determine the water quality. Here, “bio-indicator” is question condition while “upstream land use,” “flow volume,” and “EC” are problem attributes. “Water quality/dissolved matter” is an additional attribute related to the problem’s solution. Learners must determine these attributes independently