Measuring Knowledge of Precise Word Meaning

One of the significant problems of educational measurement is the need for improved vocabulary tests. A knowledge of technical vocabulary is prerequisite to comprehension of textbooks and discussions, and is often the key to basic ideas in the subject. The teacher who seeks to build concepts in the pupil's mind is constantly confronted with the problem of determining how well the pupil understands each term, yet vocabulary tests in the past have rarely been diagnostic. Furthermore, they have generally assumed that a word is either known or unknown, so that a simple test can determine the percentage of the class knowing each word. More careful analysis of the problem of word knowledge has suggested that a student may know a word more or less well, and that testing should determine the degree to which his understanding is complete rather than to say that he "knows" or "does not know" the word. In other words, it is important to determine how precise a concept he has acquired.1