stimuli are used, i. e., the words pronounced as the pupils look at them.
There is another cause of difference and also of inaccuracy. In the auditory test unfamiliar words are often mistaken for familiar ones having a similar sound, e. g., barque for bark, baron for barren, and in the visual test similarity of appearance plays a similar part. A striking case of this form of error was made by a third grade boy who marked the word amaranth as known. I said to him, 'You don't know that word, do you?' He said, 'Yes,' in a tone that implied surprise that I should question it. I then said, 'What is the word?' He replied, 'Arithmetic' Another boy for similar reasons, partly visual and partly auditory, marked 'eschar' as known and when questioned called it 'sister.'
On the other hand, young children often do not mark words that are perfectly familiar to them, because the sounds and forms without any other stimuli of suggesting words or circumstances are not sufficient to immediately arouse the sense of familiarity. One second grade boy who marked only eighteen words in the test, when questioned, showed by synonyms or definitions, or illustrations, that he knew the meaning of thirty of the words.
Individual habits of thinking or judging is probably the largest factor in tending to make the marking of words an unreliable index of the actual mental furniture of the subject of the test. Some mark as known every word that arouses the feeling of familiarity, while others mark as known only those for which they are confident they can give a correct definition. The differences in this respect are, however, most shown in the doubtful marks while the plus mark usually means the arousal of a specific idea by the word form. This idea may be vague or distinct, narrow or broad, general or detailed, correct or incorrect, but it is the idea usually aroused by the word.
Upon defining a list of words to a class of normal students after they had marked them, it was found that the errors in marking words as known and unknown usually cancelled each other, so that the number finally reported as known and unknown was for most members of the class about the same as when they were first marked.
Instruction as to what shall be the standard for deciding whether a word is known, such as "Count as known all words that you would not, as to their meaning, need to look up in a dictionary if you saw them in a sentence," helps to render the marking more uniform. Another and more accurate method of bringing about uniformity of standard is to ask the pupils to define or put in sentences some of the words, then to mark the rest according as they think themselves able or unable to indicate their meaning.
If students are asked to define a certain proportion of the words