语言测试课件.ppt

Introduction to Language Testing 语言测试简介 Chen Youlin (陈佑林) English Department School of Foreign Languages Central China Normal University St Score Rank F CF RCF PCF 100 95 90 H/D 85 75 70 E/O/F 65 50 45 40 35 30 25 20 15 10 5 2 Table 1: Percentile Scores Score Mean dd23527864 34749 33636 33636 N = 26 32525? X = 702 3039 Mean = 702 ? 26 = 27 3039 2924?d2 = 432 2924?d2 /N = 432 ? 26 = 2700 2700 . = ??d2 /N = ? = = 2700 26 -11 26 -11 26 -11 26 -11 26 -11 25 -24 25 -24 25 -24 24 -39 23 -416 23 -416 22 -525 20 -749 19 -864 3 Table 2: Standard Deviation StXYX2Y2 XY 181064100 80 257254935 346163624 43592515 502040 668366448 713193 802040 93592515 10244168 N = 10 ? X = 32 ? Y = 52 ?X2 = 164 ?Y2 = 332 ? XY= 228 [N ?? XY – ( ? X ) ( ? Y) ] 2 [10 ?228 – 32 ? 52] 2 rxy 2 = = [N ??X2–(? X) 2 ][ N ??Y2–(? Y) 2] [10 ?164 –322 ][10 ?332 – 52 2] [2280 – 1664] 2616 2 = = = [1640 – 1024][3320 – 2704] 616 ? 616 4 Table 3: Calculation of Correlation Coefficient 5 Figure 1: Norm Distribution and Standard Score -3 -2 -1 0 +1 +2 +3 (z score) 20 30 40 50 60 70 80 (T score) 200 300 400 500 600 700 800(CEEB s.) 2% 14% 34% 34% 14% 2% Suppose there is a 10-point writing task in a test and 5 testees have taken the test. Their writing scores are as follows: S1. 5 S2. 8 S3. 7 S4. 3 S5. 7 Total Score of the testees : 30 Number of Testees : 5 Full Score of the item: 10 Apply the formula: FV= Total Score (30)/N(5)/Full Score