Is Slope/Height Confusion a Problem of Graph Interpretation?
Berg & Phillips (1994) found examples of what appeared to be SHC in student responses to questions about graphs depicting the motion of cars and the filling of water tanks. They concluded that the students were responding to keywords in the question. Questions asking the students to indicate where a quantity was “more” generally elicited responses about the height of the graph, while questions about when something was happening “faster” elicited responses involving the slope of the graph. Often, of course, this strategy works. For example, a student looking at a distance-time graph can draw correct conclusions by associating more distance with higher points, and faster movement with steeper slope. On the other hand, if the student is asked when the velocity is greatest, this may be categorized as a “more” question, leading the student to incorrectly select the highest point on the distance-time curve, rather than the point with steepest slope. This type of error may not have any connec
