The Psychometric Method on the Study of Child Psychology
Matching colours, fitting pegs into holes, boxes into a nest, and shapes into their insets or matching pictures and completing jigsaws-all these performance tests have been tried out and carefully standardized as being particularly suitable for a certain age level.
The child’s score is based on the time taken and the correctness of the solution. The type of performance required is similar to that enjoyed by a normal child in a nursery school, and usually the child enters into the test with zest and enthusiasm.
Of course it is not wise to assume that an assessment of intelligence, especially at this age level, is entirely reliable. At best it is a measure of his effective level of intelligence, and not necessarily his optimum. Emotional attitude, social responsiveness, general anxiety, for instance, may prejudice his performance.
But an estimate of mental age or developmental level on such a scale as the Merrill-Palmer, as this is called, gives a useful indication of intellectual ability.
The Term an-Merrill Scale (38) is probably the best known and the most widely used in Child Guidance Clinics and by School Medical Officers. These tests are a revision and an improvement on the original Benet tests.
They include many simple performance tests suitable for very young children, are very well standardized, and are especially reliable for school children. They are standardized for children of eighteen months of age to superior adult level.
The following are the test items, which a six-year-old of normal intelligence is expected to be able to pass:
1. Knows the meaning of five words such as orange, envelope, straw, puddle, tap, eyelash, roar, scorch.
2. Can reproduce a bead chain from memory which consists of square and round beads alternatively.
3. Can detect four out of five missing features from incomplete pictures, e.g. a barrow without a wheel, a rabbit without an ear, a boot without a lace, a teapot without a handle, and a glove without a finger.
4. Can count out three, nine, five, seven, etc. bricks on request. (Three correct out of five).
5. Can distinguish differences from likeness when presented pictorially, e.g. around shape from square shapes, a black circle from white circles, when asked to show the one that is not the same as the others.
6. Can show the shortest way for a boy to go to school on a simple maze form. (Two out of three correct).
Such tests are easy to administer and a good response can readily be elicited from most children.
Recently Valentine has undertaken a useful piece of work in devising an intelligence scale suitable for children between the ages of eighteen months and eleven years based on a combination of the most satisfactory and reliable tests devised by Gesell, Porteous, Burt, Terman, and from the Merrill-Palmer Scale.
He claims that by including a large number and great variety of tests the scale is intrinsically interesting to the child and more reliable.
He purposefully makes the instructions as simple and as brief as possible, and the scale involves the use of very simple apparatus and material which is easily obtainable in order that teachers can make full use of the tests themselves.
He assumes that intelligence testing of this simple type can readily be undertaken by the teacher and claims that these tests “are primarily meant to afford a preliminary estimate of the general stage of development.”
He considers the results for children of four years and over to be the most reliable, as the tests were given to a greater number of children than in the case of those suitable for children under four.
The Scale is especially useful in the infant and junior departments and is suitable for placing the pupils “in a fairly reliable order of merit, to select those of superior and those of dull intelligence, and to give a preliminary selection of possible mental defectives.”
Although there is little that is original in this scale, the combination of well-tried tests in one battery is a valuable and a novel one.
It is outside the scope of this book to give a full account of the tremendous amount of work that has been done in recent years in mental testing. The references at the end will introduce the reader to other literature that explains the different measures of intelligence in details.