National Spanish Challenge (2026)

Reliability

nsc 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:

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

nsc 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. The relationship between variables is commonly considered strong over .7. Most standardized tests usually have a reliability coefficient of .90 or above.¹

Reliability Coefficients

for the National Spanish Challenge (2026)

			Population Size	Number of Questions (K)	Mean Score (M)	Standard Deviation (SD)	Reliability Coefficient (r)
Level Name	Category Name	Exam Part
Division A	Seat Assigned	Division A1	139.0	20.0	46.812950	8.841179	1.0
		Division A2	311.0	20.0	47.102894	9.827239	1.0
		Total	363.0	40.0	0.000000	0.000000	NaN
Division B	Seat Assigned	Division B1	142.0	28.0	71.387324	14.033084	1.0
		Division B2	473.0	28.0	73.145877	12.212610	1.0
		Total	504.0	56.0	0.000000	0.000000	NaN
Division C	Seat Assigned	Division C1	502.0	35.0	103.272908	22.525665	1.0
		Division C2	372.0	35.0	109.467742	19.181127	1.0
		Total	844.0	70.0	0.000000	0.000000	NaN
Division D	Seat Assigned	Division D1	53.0	30.0	76.018868	21.513042	1.0
		Division D2	47.0	30.0	86.723404	17.149781	1.0
		Division D3	62.0	30.0	87.822581	18.935820	1.0
		Total	121.0	90.0	0.000000	0.000000	NaN
Division E	Seat Assigned	Division E1	32.0	40.0	127.312500	23.385943	1.0
		Division E2	28.0	40.0	137.285714	20.952083	1.0
		Division E3	31.0	40.0	137.064516	19.382292	1.0
		Total	89.0	80.0	0.000000	0.000000	NaN

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