A Content Analysis of Figure Captions in Academic Journals from Four Disciplines

Background: Captions do important communicative work, but little research has investigated their content quantitatively. Literature review: Captions help facilitate learning and make retrieving information from databases easier. Yet, few studies have explored the rhetorical moves found in figure captions to better understand their communicative function. Research questions: 1. How do captions found in psychology, linguistics, biology, and technical and professional communication (TPC) journals differ in terms of length? 2. What are the rhetorical structures of figure captions in psychology, linguistics, biology, and TPC journals? 3. How do the rhetorical structures of captions in journals from these four disciplines differ? 4. To what extent does visual type interact with caption length and rhetorical structure? Research methodology: Using quantitative content analysis, I compared the frequencies of moves in captions across disciplines, determined whether the moves were conventional or optional, and identified patterns in the progression of moves in the captions that I analyzed. A supplementary analysis of the types of visuals that accompanied the captions offered insights into the findings of the caption-content analysis. Results: Results suggest a high degree of variation in the rhetorical structure of captions in academic journals. Biology captions were, on average, the longest and contained the most moves. TPC captions were the shortest and contained the fewest moves. Psychology and linguistics captions fell between the biology and TPC captions. Conclusions: Understanding variation in caption content can encourage a more rhetorical approach to caption writing. Researchers in disciplines where shorter captions are standard might consider writing elaborated captions.