If an error within a task occurs because of a fundamental misconception of a
mathematical idea or the relationship between ideas, then directing the student’s attention to a procedure-based correction within the task may be insufficient. Such an attempt to fix the error may appear successful for a specific type of task, but when students face a new, unfamiliar situation, the misconception will often reassert itself on student reasoning (Hiebert & Grouws, 2007). The same situation can occur when the misunderstandings are a combination of meaning and procedures (e.g., Fisher, 1988;Phillippe, 1992). Instead, interventions that are effective in the long term will address the lack of understanding about the meaning of the important mathematical ideas