in order to become an instance of the concept. On the other hand, natural concepts or categories are usually ill-defined. Numerous features are found in the instances of a natural category. Such concepts include biological objects, real world products, and human artefacts such as tools, clothes, houses, etc.
Let us take the example of the concept of a square. It is a well-defined concept. It must have four attributes, i.e. closed figure, four sides, each side of equal length, and equal angles.
Thus a square consists of four features connected by a conjunctive rule . In order to understand various rules for creating well- defined concepts let us look at Figure . . Take the following words and write them on separate cards, and ask the participants to read them aloud one by one.
After completion of two readings, ask them to write down the words in any order : book, law, bread, shirt, coat, paper, pencil, biscuit, pen, life, history, rice, curd, shoes, sociology, sweet, pond, potato, ice-cream, muffler, and prose. After the presentation, ask them to write down the words they read, without bothering about the order of presentation. Analyse your data to see whether recalled words show any organisation.