The paper presents a first approximation for a model of student performance in solving linear equations. General characteristics of a model are related to the extant research on equation solving. Terminology is denned and used to reconceptualize published research results. The model is presented and is followed by an examination, in terms of the model, of one student's attempts to solve a particular equation. Finally, questions for future research are posed which might lead to the elucidation of the model. The model relates levels of control (i.e., task, method, strategy, process, operation, tactic) to the features (i.e., remote and near) of equations. The control levels are viewed from an information processing perspective; a hierarchal organization is proposed with higher levels influencing activities at lower levels. The model is created to capture the school mathematics approach to solving linear equations, though it is expected that it will generalize to other contexts. † Revision of paper presented ...