Assignment 6 NA3C0005-Belle SPSS exercises 1a. Valid N TOEFL 1: LISTENING TOEFL 2: STRUCT & TOEFL 3: VOCAB & STANDARD SCORE WRITING STANDARD READING STANDARD (Tlcstd) SCORE (Tswstd) SCORE (Tvrstd) 1448 1448 1448 40 40 40 49.62 51.12 51.49 .175 .181 .176 50.00 51.00 52.00 51 54 54 6.665 6.900 6.696 44.428 47.604 44.839 -.074 -.241 -.503 .064 .064 .064 -.293 -.041 .080 .129 .129 .129 Range 39 43 38 Minimum 29 25 28 Maximum 68 68 66 71848 74019 74556 25 45.00 46.00 47.00 50 50.00 51.00 52.00 75 54.00 56.00 56.00 Missing N Mean Std. Error of Mean Median Mode Std. Deviation Variance Skewness Std. Error of Skewness Kurtosis Std. Error of Kurtosis Sum Percentiles 1b. Tlcstd: The value of Skewness is -.074 which refers to negative skewness. The graph skews to the left. Most scores are distributed over the mean. High score participants are more than low score ones. The value of Kurtosis is -.293 which means platykurtic. The Kurtosis of Tlcstd is flatter than normal kurtosis. Participants in the peak are fewer than normal distribution. Participants on the both ends are also fewer than normal distribution. Participants between peak and both ends are more than normal distribution. In terms of central tendency, when Mean, Median and Mode are equal as well as in the middle of the figures, it would be the ideal normal distribution. In this case, Mean is 49.62, Median is 50, Mode is 51. It approaches normal distribution. Another method to check the degree of normality is to compare the standard deviation (SD) and the value that the interquartile range divides 1.35 (IQR/1.35). When SD is higher than IQR/1.35, it would be heavier-than-normal tail. As SD is lower than IQR/1.35, it would be lighter-than-normal tail. While SD is equal to IQR/1.35, it would become normal distribution. In this case, SD is 6.665 and IQR/1.35 is 6.667. It approaches normal distribution. Tswstd: The value of Skewness is -.241 which refers to negative skewness. The graph skews to the left. Most scores are distributed over the mean. High score participants are more than low score ones. High score participants are more than low score ones. The value of Kurtosis is -.041 means platykurtic. The Kurtosis of Tswstd is flatter than normal kurtosis. Participants in the peak are fewer than normal distribution. Participants on the both ends are also fewer than normal distribution. Participants between peak and both ends are more than normal distribution. In terms of central tendency, Mean is 51.12, Median is 51, Mode is 54. It is hard to decide its degree of normality. Based on interquartile range, SD is 6.9 and IQR/1.35 is 7.407. Tswstd doesn’t approach normal distribution so closely. Tvrstd: The value of Skewness is -.503 which refers to negative skewness. The graph skews to the left. Most scores are distributed over the mean. High score participants are more than low score ones. High score participants are more than low score ones. The value of Kurtosis is .080 means leptokurtic. The Kurtosis of Tvrstd is sharper than normal kurtosis. Participants in the peak and on the both ends are more than normal distribution. Participants between peak and both ends are fewer than normal distribution. In terms of central tendency, Mean is 51.49, Median is 52, Mode is 54. It is hard to decide its degree of normality. Based on interquartile range, SD is 6.696 and IQR/1.35 is 6.667. Tvrstd approaches normal distribution more closely than Tswstd. 2a. SPEAK: TOEFL STANDARD SCORE TOTAL (Tstdtot) Valid N SPEAK: GRAMMAR RATING (Spgram) PRONUNCIATION RATING (Sppron) 1448 1304 1314 40 184 174 Mean 507.43 1.93 2.13 Median 510.00 1.90 2.20 497a 2 2 58.863 .454 .380 3464.867 .206 .145 -.280 .010 -.919 .064 .068 .067 -.233 -.115 1.731 Std. Error of Kurtosis .129 .135 .135 Range 337 3 3 Minimum 310 0 0 Maximum 647 3 3 734755 2521 2804 25 470.00 1.60 1.90 50 510.00 1.90 2.20 75 550.00 2.20 2.40 Missing N Mode Std. Deviation Variance Skewness Std. Error of Skewness Kurtosis Sum Percentiles 2b. Tstdtot: The value of Skewness is -.280 which refers to negative skewness. The graph skews to the left. Most scores are distributed over the mean. High score participants are more than low score ones. High score participants are more than low score ones. The value of Kurtosis is -.233 means platykurtic. The Kurtosis of Tstdtot is flatter than normal kurtosis. Participants in the peak are fewer than normal distribution. Participants on the both ends are also fewer than normal distribution. Participants between peak and both ends are more than normal distribution. In terms of central tendency, Mean is 507.43, Median is 510.00, Mode is 497. It is hard to decide its degree of normality. Based on interquartile range, SD is 58.863 and IQR/1.35 is 59.259. Tstdtot doesn’t approach normal distribution so closely. Spgram: The value of Skewness is .010 which refers to positive skewness. The graph skews to the right. Most scores are distributed lower the mean. Low score participants are more than High score ones. The value of Kurtosis is -.115 means platykurtic. The Kurtosis of Spgram is flatter than normal kurtosis. Participants in the peak and on the both ends are fewer than normal distribution. Participants between peak and both ends are more than normal distribution. In terms of central tendency, Mean is 1.93, Median is 1.90, Mode is 2. It is hard to decide its degree of normality. Based on interquartile range, SD is .454 and IQR/1.35 is .444. Spgram approaches normal distribution. Sppron: The value of Skewness is -.919 which refers to negative skewness. The graph skews to the left. Most scores are distributed over the mean. High score participants are more than low score ones. The value of Kurtosis is 1.731 means leptokurtic. The Kurtosis of Sppron is sharper than normal kurtosis. Participants in the peak and on the both ends are more than normal distribution. Participants between peak and both ends are fewer than normal distribution. In terms of central tendency, Mean is 2.13, Median is 2.20, Mode is 2. It is hard to decide its degree of normality. Based on interquartile range, SD is .380 and IQR/1.35 is .370. Sppron approaches normal distribution. 3 (i) FCE Paper 1 The value of Skewness is -.474 which refers to negative skewness. The graph skews to the left. Most scores are distributed over the mean. High score participants are more than low score ones. The value of Kurtosis is .030 means leptokurtic. The Kurtosis of FCE Paper 1 is sharper than normal kurtosis. Participants in the peak and on the both ends are more than normal distribution. Participants between peak and both ends are fewer than normal distribution. In terms of central tendency, Mean is 25.94, Median is 26.90, Mode is 27. It is hard to decide its degree of normality. Based on interquartile range, SD is 4.896 and IQR/1.35 is 4.889. FCE Paper 1 approaches normal distribution. FCE PAPER 1: N CAMB. SCALED SCORE TOTAL Valid Missing 1359 129 Mean 25.94 Median 26.90 27a Mode Std. Deviation 4.896 Variance 23.976 Skewness -.474 Std. Error of Skewness .066 Kurtosis .030 Std. Error of Kurtosis .133 Range 31 Minimum 10 Maximum 40 Sum Percentiles 35259 25 22.50 50 26.90 75 29.10 (ii) FCE Paper 2 The value of Skewness is -.495 which refers to negative skewness. The graph skews to the left. Most scores are distributed over the mean. High score participants are more than low score ones. The value of Kurtosis is .998 means leptokurtic. The Kurtosis of FCE Paper 2 is sharper than normal kurtosis. Participants in the peak and on the both ends are more than normal distribution. Participants between peak and both ends are fewer than normal distribution. In terms of central tendency, Mean is 24.30, Median is 24.4, Mode is 23. It is hard to decide its degree of normality. Based on interquartile range, SD is 6.043 and IQR/1.35 is 5.778. FCE Paper 2 doesn’t approach normal distribution so closely. Statistics FCE PAPER 2: N CAMB. SCALED SCORE TOTAL Valid Missing 1357 131 Mean 24.30 Median 24.40 Mode 23 Std. Deviation 6.043 Variance 36.518 Skewness -.495 Std. Error of Skewness .066 Kurtosis .998 Std. Error of Kurtosis .133 Range 40 Minimum 0 Maximum 40 Sum Percentiles 32979 25 20.70 50 24.40 75 28.50 (iii) FCE Paper 4: Grade The value of Skewness is .561 which refers to positive skewness. The graph skews to the right. Most scores are distributed lower the mean. Low score participants are more than High score ones. The value of Kurtosis is -.935 means platykurtic. The Kurtosis of FCE Paper 4: Grade is flatter than normal kurtosis. Participants in the peak and on the both ends are fewer than normal distribution. Participants between peak and both ends are more than normal distribution. In terms of central tendency, Mean is 1.96, Median is 2.00, Mode is 1. It is hard to decide its degree of normality. Based on interquartile range, SD is .996 and IQR/1.35 is 1.481. FCE Paper 4: Grade doesn’t approach normal distribution so closely. Statistics FCE PAPER 4: N GRADE Valid Missing 1344 144 Mean 1.96 Median 2.00 Mode 1 Std. Deviation .996 Variance .992 Skewness .561 Std. Error of Skewness .067 Kurtosis -.935 Std. Error of Kurtosis .133 Range 3 Minimum 1 Maximum 4 Sum Percentiles 2640 25 1.00 50 2.00 75 3.00 (iv) FCE Paper 5: Fluency rating The value of Skewness is -.399 which refers to negative skewness. The graph skews to the left. Most scores are distributed over the mean. High score participants are more than low score ones. The value of Kurtosis is .106 means leptokurtic. The Kurtosis of FCE Paper 2 is sharper than normal kurtosis. Participants in the peak and on the both ends are more than normal distribution. Participants between peak and both ends are fewer than normal distribution. In terms of central tendency, Mean is 3.57, Median is 4.00, Mode is 4. It is hard to decide its degree of normality. Based on interquartile range, SD is .927 and IQR/1.35 is .741. FCE Paper 5: Fluency rating doesn’t approach normal distribution so closely. Statistics N Valid Missing 1379 109 Mean 3.57 Median 4.00 Mode 4 Std. Deviation .927 Variance .860 Skewness -.399 Std. Error of Skewness .066 Kurtosis .106 Std. Error of Kurtosis .132 Range 5 Minimum 0 Maximum 5 Sum Percentiles 4927 25 3.00 50 4.00 75 4.00