Previous research has shown that organic chemistry students struggle with the electron-pushing formalism used by practicing organic chemists and taught in undergraduate and graduate courses. Recent research has indentified a list of concepts that faculty consider important to master before focusing upon learning the electron-pushing formalism. These concepts include, but are not limited to, electronegativity, bond polarity, Lewis acid-base theory, and identification of nucleophilic and electrophilic sites within organic molecules. Each of these concepts plays an important role in understanding reactivity. Through semi-structured interviews, we explored organic chemistry students’ ideas about nucleophiles and electrophiles: definitions/defining characteristics, examples, and how they approach identifying these types of species in reactions commonly seen throughout the introductory organic chemistry sequence.  Manuscripts were published in Chemistry Education Research and Practice reporting the importance to students of charges and mechanisms and a concept map analysis of students' understanding of the structure and function of both nucleophiles and electrophiles.