Chapter 7 Knowledge learning and instruction o7. 1.3 How should concepts be taught? o 3)distinguish between defining and characteristic features. Defining features are features necessary and sufficient for defining a concept. e.g. If an integer is evenly divisible by two, this feature is a necessary characteristic of an even number Being divisible by two is also enough to guarantee that integer is an even number. So, divisibility by two is sufficient for evenness of a number. Other example: a widow is a woman who has previously been married(a necessary but not sufficient feature) and whose husband has died (a necessary and sufficient feature) o A characteristic feature is a property typical ofChapter 7 Knowledge learning and instruction ⚫ 7.1.3 How should concepts be taught? ⚫ (3) distinguish between defining and characteristic features. Defining features are features necessary and sufficient for defining a concept. e.g. If an integer is evenly divisible by two, this feature is a necessary characteristic of an even number.Being divisible by two is also enough to guarantee that integer is an even number. So, divisibility by two is sufficient for evenness of a number. Other example: a widow is a woman who has previously been married(a necessary but not sufficient feature) and whose husband has died(a necessary and sufficient feature) ⚫ A characteristic feature is a property typical of