Shand, Kristen. "The Interplay of Graph and Text in the Aquisition of Historical Constructs." Theory and Research in Social Education 37(3) (2009): 300-324.
Graphs are often conjoined with text passages in history textbooks to help students comprehend complex constructs. Four linkages connect text and graphs: appropriate elements, fitting patterns, suitable labels and causal markers. Graphs in current textbooks contain few such linkages and seldom mirror the construct under study. An experiment conducted with seventh grade students investigated the effect on construct comprehension of loosely and tightly linked graphs. The experiment (n=118), employed a mixed-model design with reading ability as a between -subjects factor and graph treatments as a within-subjects factor. An analysis of variance with planned Helmert contrasts showed that proficient and advanced readers scored significantly higher on construct comprehension with a tight graph supporting a text passage as opposed to a loose graph.