This manuscript describes the relationship between students' redox understandings and confidence as measured by the Redox Concept Inventory (ROXCI) which assesses symbolic and particulate redox concepts. The ROXCI was administered to two samples of 1st- and 2nd-semester general chemistry students after the students were taught and tested on redox concepts in their classrooms. Cluster analysis was used to identify groups of students with similar response patterns, based upon both total scores and average confidence on the ROXCI. Three clusters of students were identified in both samples: students with (1) moderate total scores and high confidence, (2) low total scores and low confidence, and (3) low total scores but high confidence. Clusters were further analyzed at an individual item level using average confidence, individual item difficulties, and the Confidence Discrimination Quotient (CDQ). Findings align with the Dunning-Kruger effect, i.e. in which students demonstrated a false sense of confidence regarding their own poor performance, and therefore, exemplify meta-ignorance. Descriptions of the clusters, example misconceptions held by the students regarding oxidation numbers and electron transfer, and the implications of this research are discussed.