《英语测试》作业参考答案.docVIP

《英语测试》作业参考答案 1. Identify the scales represented by the following kinds of data: Solution: Raw scores from a listening comprehension test Ordinal scale Adjectives on a word-association test Nominal scale Percentile scores from a spelling test Ordinal scale Speed of note-taking in words per minute Ratio scale I.Q.-equivalent scores on a vocabulary test Interval scale z-scores on the TOEFL Interval scale The number of instrumentally motivated students in class Nominal scale 2.Given the following raw score distribution on a spelling test of 25 items, calculate (a) ordinal ratings, (b) percentage scores, (c) percentile ranks: 6, 8, 9, 11, 12, 12, 14, 15, 19, 19, 21, 25. Solution: Raw scores Ordinal ratings Percentage Scores Percentile Ranks 25 1st 100 95.8 21 2nd 84 87.5 19 3rd 76 75.0 19 4th 76 75.0 15 5th 60 62.5 14 6th 56 54.2 12 7th 48 41.7 12 8th 48 41.7 11 9th 44 29.2 9 10th 36 20.8 8 11th 32 12.5 6 12th 24 4.2 3.If you administered a multiple-choice test of phrasal verb usage to a class of ten students and got the following distribution of scores: 11, 13, 16, 16, 18, 20, 20, 25, 27, 29, what would be the corresponding z-scores, T-scores, and normal distribution area proportions if the standard deviation is 5.95? Solution: Raw scores z-scores T-scores Normal distribution area proportions 29 1.597 65.97 94.49 27 1.261 62.61 89.63 25 0.925 59.25 82.24 20 0.084 50.84 53.35 20 0.084 50.84 53.35 18 -0.252 47.48 40.05 16 -0.588 44.12 27.81 16 -0.588 44.12 27.81 13 -1.093 39.07 13.73 11 -1.429 35.71 7.65 4In a normal distribution, what proportion of the scores lie between plus and minus one standard deviation? Between plus and minus two standard deviations? Solution: ~ 1: 84.13% -2 ~ 1 81.58% Compute item difficulty and the proportion incorrect for each of the items in the following scoring matr