The National Spanish Exam 2018

Reliability

NSE recognizes that test reliability is defined as the degree to which the test gives consistent results each time it is given.

In other words, reliability answers the following questions:

  1. Can I depend on the test to measure the same outcomes consistently?
  2. Given all the other variables being the same, will the test produce the same results again?

NSE uses the Kuder-Richardson 21 formula to calculate reliability coefficients:

r (reliability) = (K)(SD2)-M(K-M)⁄(SD2)(K-1)

K = the number of items in the list
SD = the standard deviation of the scores
M = the mean of the scores

The scores of reliability are judged against a perfect score of 1.00. The closer the reliability coefficient is to 1.00, the better it is. Most standardized tests usually have a reliability coefficient of .90 or above.1

Reliability Coefficients

for the 2018 National Spanish Exam

Level Pre 01 Vocabulary Grammar Achievement Reading Listening Performance Total
Classroom Experience (N=630)
  Mean Raw Score 77.2 0.0 157.1 39.6 40.4 0.0 157.1
  Standard Deviation 15.7 0.0 28.9 9.9 9.0 0.0 28.9
  Reliability coefficient 0.938 ? 0.965 0.762 0.712 ? 0.888
Outside Experience (N=198)
  Mean Raw Score 82.3 0.0 166.5 41.5 42.7 0.0 166.5
  Standard Deviation 12.8 0.0 23.8 9.1 7.5 0.0 23.8
  Reliability coefficient 0.920 ? 0.955 0.714 0.571 ? 0.830
Bilingual (N=55)
  Mean Raw Score 87.1 0.0 170.1 41.7 41.3 0.0 170.1
  Standard Deviation 19.1 0.0 34.5 8.7 11.2 0.0 34.5
  Reliability coefficient 0.979 ? 0.984 0.688 0.814 ? 0.920
Level 01 Vocabulary Grammar Achievement Reading Listening Performance Total
Classroom Experience (N=6508)
  Mean Raw Score 75.4 60.0 135.4 73.5 81.9 155.5 290.8
  Standard Deviation 20.2 19.6 37.2 19.4 19.6 36.1 68.1
  Reliability coefficient 0.964 0.947 0.973 0.958 0.971 0.978 0.985
Outside Experience (N=1448)
  Mean Raw Score 83.9 67.0 150.9 79.2 87.6 166.9 317.8
  Standard Deviation 17.5 18.6 33.8 18.6 17.4 33.3 61.6
  Reliability coefficient 0.965 0.945 0.972 0.962 0.974 0.980 0.985
Bilingual (N=391)
  Mean Raw Score 89.7 68.6 158.4 83.0 88.3 171.3 329.7
  Standard Deviation 17.3 20.2 35.3 19.5 20.4 37.5 65.3
  Reliability coefficient 0.979 0.957 0.978 0.973 0.985 0.987 0.989
Level 1 Vocabulary Grammar Achievement Reading Listening Performance Total
Classroom Experience (N=33399)
  Mean Raw Score 74.5 53.3 127.8 67.1 70.4 137.6 265.4
  Standard Deviation 20.8 19.3 37.5 20.8 22.5 39.9 72.3
  Reliability coefficient 0.966 0.942 0.972 0.959 0.968 0.978 0.985
Outside Experience (N=5214)
  Mean Raw Score 85.2 61.4 146.6 73.7 80.7 154.4 301.0
  Standard Deviation 17.5 18.8 33.7 19.3 20.5 36.8 65.5
  Reliability coefficient 0.968 0.942 0.970 0.958 0.973 0.979 0.985
Bilingual (N=2187)
  Mean Raw Score 91.8 66.6 158.4 74.8 85.3 160.1 318.4
  Standard Deviation 14.8 17.9 29.9 20.4 21.5 39.4 62.4
  Reliability coefficient 0.976 0.940 0.968 0.964 0.983 0.984 0.986
Level 2 Vocabulary Grammar Achievement Reading Listening Performance Total
Classroom Experience (N=34592)
  Mean Raw Score 55.7 41.2 96.9 73.4 75.0 148.5 245.4
  Standard Deviation 18.4 21.2 36.3 20.3 22.0 39.1 68.3
  Reliability coefficient 0.936 0.956 0.967 0.962 0.971 0.980 0.982
Outside Experience (N=1766)
  Mean Raw Score 69.4 49.5 118.9 77.1 83.7 160.8 279.7
  Standard Deviation 19.9 21.1 37.6 19.5 20.8 37.0 66.0
  Reliability coefficient 0.956 0.953 0.971 0.963 0.978 0.982 0.983
Bilingual (N=2931)
  Mean Raw Score 83.5 56.8 140.2 74.9 86.9 161.9 302.1
  Standard Deviation 18.0 19.3 34.3 20.3 20.0 36.8 61.5
  Reliability coefficient 0.967 0.944 0.969 0.964 0.981 0.982 0.983
Level 3 Vocabulary Grammar Achievement Reading Listening Performance Total
Classroom Experience (N=27392)
  Mean Raw Score 50.2 49.2 99.4 70.9 64.0 134.8 234.3
  Standard Deviation 17.7 19.7 33.9 18.7 20.5 35.3 62.2
  Reliability coefficient 0.930 0.945 0.961 0.950 0.955 0.970 0.977
Outside Experience (N=1737)
  Mean Raw Score 64.0 53.8 117.8 73.1 74.2 147.3 265.2
  Standard Deviation 22.2 19.8 38.5 19.1 21.2 36.6 66.8
  Reliability coefficient 0.963 0.946 0.972 0.956 0.967 0.976 0.982
Bilingual (N=3162)
  Mean Raw Score 82.2 65.8 147.9 74.5 79.9 154.4 302.3
  Standard Deviation 18.9 18.1 34.3 20.2 20.6 37.4 61.3
  Reliability coefficient 0.969 0.941 0.972 0.963 0.972 0.980 0.983
Level 4 Vocabulary Grammar Achievement Reading Listening Performance Total
Classroom Experience (N=16078)
  Mean Raw Score 51.3 40.2 91.5 74.4 67.5 141.8 233.4
  Standard Deviation 18.6 19.7 33.4 20.5 21.5 38.4 63.9
  Reliability coefficient 0.937 0.948 0.960 0.964 0.962 0.977 0.979
Outside Experience (N=1035)
  Mean Raw Score 65.2 42.7 107.9 77.6 73.2 150.8 258.7
  Standard Deviation 20.8 19.9 36.2 21.3 21.4 39.3 65.7
  Reliability coefficient 0.957 0.948 0.967 0.971 0.967 0.981 0.981
Bilingual (N=3186)
  Mean Raw Score 77.1 50.3 127.5 77.9 77.1 155.0 282.5
  Standard Deviation 17.9 19.2 33.3 21.8 20.7 39.4 61.6
  Reliability coefficient 0.955 0.942 0.963 0.974 0.969 0.982 0.981
Level 5 Vocabulary Grammar Achievement Reading Listening Performance Total
Classroom Experience (N=5566)
  Mean Raw Score 60.1 45.7 105.8 71.4 67.4 138.8 244.6
  Standard Deviation 19.9 19.8 35.1 20.6 22.6 39.6 68.2
  Reliability coefficient 0.949 0.946 0.964 0.961 0.967 0.978 0.982
Outside Experience (N=415)
  Mean Raw Score 67.5 45.2 112.8 73.3 71.7 144.9 257.7
  Standard Deviation 18.8 19.7 33.4 21.1 24.3 42.2 68.0
  Reliability coefficient 0.947 0.945 0.961 0.965 0.975 0.982 0.983
Bilingual (N=1275)
  Mean Raw Score 73.8 59.5 133.3 75.2 74.3 149.5 282.8
  Standard Deviation 15.3 19.8 30.7 20.3 22.0 39.0 59.3
  Reliability coefficient 0.927 0.948 0.957 0.964 0.970 0.980 0.979
Level 6 Vocabulary Grammar Achievement Reading Listening Performance Total
Classroom Experience (N=519)
  Mean Raw Score 73.2 55.5 128.7 72.7 75.9 148.5 277.2
  Standard Deviation 17.5 19.9 32.9 17.2 19.7 33.4 59.7
  Reliability coefficient 0.945 0.947 0.963 0.942 0.962 0.971 0.979
Outside Experience (N=131)
  Mean Raw Score 75.7 53.6 129.4 71.6 81.3 152.9 282.2
  Standard Deviation 15.3 19.0 29.3 19.3 17.8 34.1 54.8
  Reliability coefficient 0.931 0.940 0.951 0.955 0.961 0.974 0.975
Bilingual (N=488)
  Mean Raw Score 83.2 68.3 151.5 71.0 83.6 154.6 306.1
  Standard Deviation 14.7 17.3 27.9 19.3 20.5 37.2 57.0
  Reliability coefficient 0.945 0.937 0.958 0.954 0.977 0.980 0.980

1John A. Kaufhold, Basic Statistics for Educational Research (New York: iUniverse, Inc., 2007) pp. 43-46.