Defining a "misconception" as an error of translation (transformation, correspondence, interpolation, interpretation) between two different kinds of information which causes students to have incorrect expectations, a Taxonomy of Errors has been developed to examine student misconceptions in an introductory biology course for science majors. Two forms of the Taxonomy are included. Major categories in the long form include: (1) primary encoding errors-missing and incorrect/faulty knowledge; (2) errors of relationship-missing and incorrect/faulty relationships; (3) errors of processing encoded information-algorithms missing, incorrect, or correct with an error; (4) errors of management, including failure to recognize or resolve conflicts or contradictions in knowledge, to generate effective "runnable" models, to develop effective and efficient metastrategies, and failure of confidence in using knowledge. Specific examples are presented to illustrate student misconceptions in terms of the Taxonomy. For example, when asked if a single base deletion in mRNA, tRNA, sense strand of DNA, nonsense strand of DNA, or both strands of DNA (both strands of DNA is the correct answer), 39 out of 72 students answered it incorrectly, suggesting missing knowledge. Examples of research studies are cited and potential inadequacies of the Taxonomy are discussed. (Author/JN)