WS/ZF-R. RUDOLF WEISS TEST OF WORDS AND TEST OF NUMBERS
These two tests are designed to measure verbal and numerical skills in persons aged 8-19 and are supposed to be complementary to the fluid intelligence assessement by the CFT-20R test.
Description: Verbal skills are measured by the vocabulary test (Test of Words) which assess the passive word resource. All tasks consist in finding synonyms for key words from among five words provided. Test of Words has two versions with two different difficulty levels: one for persons aged 8-12 and the other for adolescents aged 13-19. Each version includes 30 items consisting of key words (mainly substantives) and words from among which the test-taker should choose synonyms. In each case the number of the latter is always 5. The administration time of the test is limited to 12 minutes.
To measure numerical skills the tasks with sequences of numbers were used – the goal is always to fill the gap in the sequence. As in the case of vocabulary tasks the numerical tasks have closed sets of answers – the correct answer should be chosen from among five numbers. Test of Numbers includes 21 tasks each of which consists in filling the gap in a sequence of 6 numbers with a seventh one chosen from among five numbers provided. This requires finding out of the rule which governs each sequence or numerical relations between its elements. The administration time is limited to 12 minutes.
Both tests have their B-forms that can be treated as collateral.
Reliability: Test of Words – high internal coherence (split-half reliability > 0,80) of the scores of school children above 10 years of age (in the children version) and in the case of adolescents above 14 years of age (in the adolescents version). In the case of other samples reliability coefficients do not allow to use the test in individual assessment. The absolute stability was moderately high or high, lower only among children below 12 years. These results do not improve when the test is administered again after three weeks.
Test of Numbers – high internal coherence (split-half reliability > 0,80) of the scores of school children above 9 years of age. In the two “youngest” samples the coefficient values are lower – in the case of these children it is not recommended to use the test in individual assessment. Low internal stability in most of the samples, one exception being the sample of the 17-years-old where the value of the corelation coefficient proved high. These results do not improve when the test is administered after three weeks.
Validity: Positive evidence of WS/ZF-R validity is the way scores change with the test-taker's age (in accordance with the theory of crystallized intelligence); differences in scores related to the type of school; moderate correlations with the scores in fluid inteligence tests such as Cattel's (CFT-20) and Raven's (TMS-K) and quite high correlations with test-takers' school marks proved especially for grades 5-6 of the primary school, grade 1 of the middle school and grade 1-2 of the high school.
Norms: For school children aged 8-19 (national samples) developped separately for each test.
Application: WS/ZF-R are tests designed to measure crystallized skills. The comparison of theirs scores with those in the fluid intelligence tests allows to judge the degree in which the respondent used his/her intellectual capability to acquire culturally important knowledge and skills. WS/ZF-R can also help to predict how succesful children may be during their career at school. Both tests can also be recommended for use in school counselling e.g. to identify school children in need of additional help from their teachers. Thanks to collateral forms (the B-form) both tests can be administered again within a short period of time.