Are figure legends sufficient? Evaluating the contribution of associated text to biomedical figure comprehension

Table 1 Sample data for rhetorical unit evaluation.

Figure + Associated text	Subject-Generated Text Structured by Rhetorical Units
	Purpose	Methods	Results	Conclusions	Other Criteria
Fig+L	Effect of pH...	Enzyme kinetics	Hard to say, need detailed fitting data	Don't know	Full text
Fig+L+T+A	The goal of...	X-ray crystallography...	Hydrogen bonds...	RNA binding of protein...	Methods are still lacking
F+Legend+T+A	To show that...	A is just a chart of...	Affinity of TF...	A model for the formation...	How was the final model arrived at (part c)?

Space limitations prevent us from including all the text descriptions for the four rhetorical units. Legend (L), title (T), and abstract (A). The original data are available at http://www.bioex.us.com/evaluation_data/JudgeEvaluation.xml.