1. Orange. “An orange is to eat.” “It is yellow and grows on a tree.” (Both full credit.)
  2. Bonfire. “You burn it outdoors.” “You burn some leaves or things.” “It’s a big fire.” (All full credit.)
  3. Roar. “A lion roars.” “You holler loud.” (Full credit.)
  4. Gown. “To sleep in.” “It’s a nightie.” “It’s a nice gown that ladies wear.” (All full credit.)
  5. Puddle. “You splash in it.” “It’s just a puddle of water.” (Both full credit.)
  6. Straw. “It grows in the field.” “It means wheat-straw.” “The horses eat it.” (All full credit.)
  7. Rule. “The teacher makes rules.” “It means you can’t do something.” “You make marks with it,” i.e., a ruler, often called a rule by school children. (All full credit.)
  8. Afloat. “To float on the water.” “A ship floats.” (Both full credit.)
  9. Eyelash. If the child says, “It’s over the eye,” tell him to point to it, as often the word is confused with eyebrow.
  10. Copper. “It’s a penny.” “It means some copper wire.” (Both full credit.)
  11. Health. “It means good health or bad health.” “It means strong.” (Both full credit.)
  12. Guitar. “You play on it.” (Full credit.)
  13. Mellow. If the child says, “It means a mellow apple,” ask what kind of apple that would be. For full credit the answer must be “soft,” “mushy,” etc.
  14. Pork. If the answer is “meat,” ask what animal it comes from. Half credit if wrong animal is named.
  15. Plumbing. “You fix pipes.” (Full credit.)
  16. Southern. If the answer is “Southern States,” or “Southern California,” say: “Yes; but what does ‘southern’ mean?” Do not credit unless explanation is forthcoming.
  17. Noticeable. “You notice a thing.” (Full credit.)
  18. Civil. “Civil War.” (Failure unless explained.) “It means to be nice.” (Full credit.)
  19. Treasury. Give half credit for definitions like “Valuables,” “Lots of money,” etc.; i.e., if the word is confused with treasure.
  20. Ramble. “To go about fast.” (Half credit.)
  21. Nerve. Half credit if the slang use is defined, “You’ve got nerve,” etc.
  22. Majesty. “What you say to a king.” (Full credit.)
  23. Sportive. “To like sports.” (Half credit.) “Playful” or “happy.” (Full credit.)
  24. Hysterics. “You laugh and cry at the same time.” “A kind of sickness.” “A kind of fit.” (All full credit.)
  25. Repose. “You pose again.” (Failure.)
  26. Coinage. “A place where they make money.” (Half credit.)
  27. Dilapidated. “Something that’s very old.” (Half credit.)
  28. Conscientious. “You’re careful how you do your work.” (Full credit.)
  29. Artless. “No art.” (Failure unless correctly explained.)
  30. Priceless. “It has no price.” (Failure.)
  31. Promontory. “Something prominent.” (Failure unless child can explain what it refers to.)
  32. Milksop. “You sop up milk.” (Failure.)
  33. Harpy. “A kind of bird.” (Full credit.)
  34. Exaltation. “You feel good.” (Full credit.)
  35. Retroactive. “Acting backward.” (Full credit.)
  36. Theosophy. “A religion.” (Full credit.)

It is seen from the above examples that a very liberal standard has been used. Leniency in judging definitions is necessary because the child’s power of expression lags farther behind his understanding than is true of adults, and also because for the young subject the word has a relatively less unitary existence.

Remarks. Our vocabulary test was derived by selecting the last word of every sixth column in a dictionary containing approximately 18,000 words, presumably the 18,000 most common words in the language. The test is based on the assumption that 100 words selected according to some arbitrary rule will be a large enough sampling to afford a fairly reliable index of a subject’s entire vocabulary. Rather extensive experimentation with this list and others chosen in a similar manner has proved that the assumption is justified. Tests of the same 75 individuals with five different vocabulary tests of this type showed that the average difference between two tests of the same person was less than 5 per cent. This means that any one of the five tests used is reliable enough for all practical purposes. It is of no special importance that a given child’s vocabulary is 8000 rather than 7600; the significance lies in the fact that it is approximately 8000 and not 4000, 12,000, or some other widely different number.

It may seem to the reader almost incredible that so small a sampling of words would give a reliable index of an individual’s vocabulary. That it does so is due to the operation of the ordinary laws of chance. It is analogous to predicting the results of an election when only a small proportion of the ballots have been counted. It is known that a ballot box contains 600 votes, and if when only 30 have been counted it is found that they are divided between two candidates in the proportion of 20 and 10, it is safe to predict that a complete count will give the two candidates approximately 400 and 200 respectively.[61] In 1914 about 1,000,000 votes were cast for governor in California, and when only 10,000 votes had been counted, or a hundredth of all, it was announced and conceded that Governor Johnson had been reëlected by the 150,000 plurality. The completed count gave him 188,505 plurality. The error was less than 4 per cent of the total vote.

The vocabulary test has a far higher value than any other single test of the scale. Used with children of English-speaking parents (with children whose home language is not English it is of course unreliable), it probably has a higher value than any three other tests in the scale. Our statistics show that in a large majority of cases the vocabulary test alone will give us an intelligence quotient within 10 per cent of that secured by the entire scale. Out of hundreds of English-speaking children we have not found one testing significantly above age who had a significantly low vocabulary; and correspondingly, those who test much below age never have a high vocabulary.

Occasionally, however, a subject tests somewhat higher or lower in vocabulary than the mental age would lead us to expect. This is often the case with dull children in cultured homes and with very intelligent children whose home environment has not stimulated language development. But even in these cases we are not seriously misled, for the dull child of fortunate home surroundings shows his dullness in the quality of his definitions if not in their quantity; while the bright child of illiterate parents shows his intelligence in the aptness and accuracy of his definitions.

We have not worked out a satisfactory method of scoring the quality of definitions in our vocabulary test, but these differences will be readily observed by the trained examiner. Definitions in terms of use and definitions which are slightly inaccurate or hazy are quite characteristic of the lower mental ages. Children of the lower mental age have also a tendency to venture wild guesses at words they do not know. This is especially characteristic of retarded subjects and is another example of their weakness of auto-criticism. One feeble-minded boy of 12 years, with a mental age of 8 years, glibly and confidently gave definitions for every one of the hundred words. About 70 of the definitions were pure nonsense.

This vocabulary test was arranged and partially standardized by Mr. H. G. Childs and the writer in 1911. Many experiments since then have proved its value as a test of intelligence.

VIII, Alternative test 1: naming six coins

Procedure is exactly as in [VI, 5] (naming four coins). The dollar should be shown before the half-dollar.