Concept maps (which show the relationship among concepts) are often discussed in the field of education as elements that facilitate the learning experience. In this study, I analyzed whether the concept maps used by knowledge organization researchers employ semiotic theory. I examined the following conference proceedings in their entirety: The International Society for Knowledge Organization (ISKO) and Advances in Classification Research: proceedings of the American Society for Information Science and Technology (ASIS SIG/CR). My findings determined that Peirce’s framework was the basis for the largest number of maps, that concept maps are the most frequently used form of visual representation, and that most researchers who use concept maps in their presentation use only one. Additional analysis revealed that the majority of contributors who used concept maps following Peirce’s framework were employed in the United States as professors. I deployed content analysis as my methodology to measure the most frequently used terms.