In the context of education, good explanation in teaching is essential for unlocking the students' understanding of the subject. It develops students' logical thinking and provides guidance by inductive judgment to generalizing. Leinhardt (1990: 3-4) distinguished between two types of teaching related to explanations: instructional and disciplinary. According to Leinhardt (1990), instructional explanations aim to explain concepts, procedures, events, ideas and classes of problems in order to help students understand, learn and use information in a flexible way. Disciplinary explanations are built around a core of conventions within each particular discipline and try to explain what constitutes evidence, what is assumed, and what the agenda for the discipline is. They provide the legitimacy of new knowledge, reinterpret old knowledge, and challenge and address existing knowledge (Leinhardt 1990). From a learning perspective, explanation holds a special place as one of the core critical thinking skills (Facione 1990). Good critical thinkers, according to Facione (1998: 5), are those who can explain what they think and how they arrived at that judgment. The Delphi Study expert panel, cited by Facione (1998: 6), defined explanation as being able "to state the results of one's reasoning; to justify that reasoning in terms of the evidential, conceptual, methodological, criteriological, and contextual considerations upon which one's results were based; and to present one's reasoning in the form of cogent arguments". Explanation that works (Lipton 2004) is one that is "sticky" (people remember it, think about it, and can repeat it, often even days or weeks later), is easily communicated (people can explain it to each other), and guides thinking in new and better directions (it leads to new kinds of reasoning, which are not only more constructive and accurate but more engaging).