Many worthwhile mathematical activities can be generated by an overgeneralization. Some conjectures and their verification are described, with some exploration of historical procedures. (MNS)

A set of brief reflections about different aspects of mathematical errors and their roles in education is given. The nature and variety of errors and their positive use in learning mathematics are highlighted. (MNS)

A new potential for using microcomputers to help secondary school students learn mathematics through self-diagnosis and self-remediation is contrasted with current uses of computers for diagnosis and remediation. Research findings and software are cited in the discussion. (MNS)

Using computers to provide diagnosis and remediation in mathematics is emphasized. Some essential features of technology-supported learning environments are discussed, as well as features that facilitate their use. Illustrated is a computer environment for learning algebra. (MNS)

Four different conceptions of error-making from a pedagogical perspective are developed. Using errors as springboards for learning is advocated, so that better understanding of content and of the nature of mathematics results. (MNS)

This is a report of an application of the interpretation of errors and springboards in a real-life situation. If and why we need to reduce fractions is considered. (MNS)

A common mistake in adding fractions involves the confusion betwen the concepts of fraction and ratio. A coherent system to operate with ratios is developed. (MNS)

Several intuitive proofs for evaluating specific infinite expressions are given. Observations on intuition and errors in mathematics are included. (MNS)

How computers have affected diagnosis in mathematics is discussed. A distinction is made between errors and mistakes, followed by consideration of computers as a diagnostic tool. The development of algorithms to diagnose errors and of models of student performance is described. (MNS)

Analysis of errors children make is modeled both with and without computers. Patterns of thinking are traced for a fifth grader, with the discussion focused on getting clues for remedial instruction by analyzing the dialog. (MNS)

Illustrated first is the case in which a wrong procedure (with fractions) leads to a correct result. Trying to justify why it works in this case and looking for similar patterns involved interesting algebraic considerations as well as use of computers. (MNS)

A series of common misconceptions with regard to infinite sets is considered. Several notions of infinite numbers proposed by different mathematicians are compared. It is argued that so-called errors should rather be called alternative conceptions. (MNS)

Research on structural learning theory is reviewed as a base for designing computer-assisted instruction programs. An intelligent "Rule Tutor" emphasizing diagnosis and remediation for whole number concepts is described. (MNS)

Discusses the nature and importance of iconic learning (image-related) and a medium to facilitate assessment at the iconic level of knowing. The medium consists of a series of self-inking rubber stamps made with iconic representations of numeration blocks and sticks in denominations of 1, 10, and 100. (JN)