VALIDITY,
RELIABLILITY,
WASHBACK
Carolina Salazar
17.02.2014
The test measures what it is
intended to measure.

VALIDITY
CONTENT VALIDITY
Content Validity

TEST

RELEVANT!!!
skills

structures

concepts
Judging Content Validity

SPECIFICATIONS

ACTUAL TEST
Importance of Content Validity

Content
General
Content Construct
WASHBACK
ValidityValidity Validity
Validity
CRITERION-RELATED
VALIDITY
Criterion-related Validity

Assessment
DO
Test results THEY AGREE?
results
Kinds of Criterion-related Validity

Concurrent

C-R V.

Test =
criterion

EXAMPLES?Test 
Predictive

Criterion
Examples of Criterion-related Validity
One of the objectives of a Spanish course is to measure speaking
(especially pronunciation of vowels) and writing (especially
comments on readings). Testing these abilities in detail could take up
to 2 hours per student (too impractical), but only 20 minutes can be
devoted to each student. Can a twenty-minute session give an
accurate estimate of the student’s ability in these functions?
After the students finish the 20-min test, the teacher decides to
choose a sample of the students taking the evaluation to subject
them to the full 2-hour one. Then he compares the results.
Examples of Criterion-related Validity

A student takes a placement test for English. He receives the results
and is placed in 3rd level. How well did the test predict the most
appropriate class for the student? Will he succeed and pass?
SCORING VALIDITY
Scoring Validity
READING-COMPREHENSION TEST
FACE VALIDITY
Face Validity
HOW TO MAKE TESTS
MORE VALID?
Tips for more valid tests

1. Set specifications
2. Use direct testing
3. Relate the scoring to what you are testing
The test is repeatable.

RELIABILITY
Reliability
Reliability Exemplified
STUDENT

SCORE (A)

SCORE (B)

T

80

52

U

61

78

V

98

59

W

43

68

X

52

66

Y

40

98

Z

28

50

• 100-item test
• SCORE A: Monday
• SCORE B: Tuesday
STUDENT

SCORE (A)

SCORE (B)

A

91

97

B

88

83

C

46

50

D

54

52

E

99

99

F

66

70

G

27

25
The Reliability Coefficient

0

.....

1
Role of Reliability

…THE MORE IMPORTANT THE DECISIONS, THE
GREATER RELIABILITY WE MUST DEMAND.
How do we arrive to the R.C.?
Testretest

R.C.
Alternate
forms
Split-half
SCORER RELIABILITY
Scorer Reliability
HOW TO MAKE TESTS
MORE RELIABLE?
Tips for more reliable tests
1. Use enough items
2. Do not give too much freedom
3. Write unambiguous items
4. Provide clear instructions
5. Ensure that tests are legible
6. Make candidates familiar with formats/techniques
7. Provide non-distracting and uniform conditions
8. Use items that allow objective scoring
9. Provide a detailed scoring key
10. Train scorers
11. Agree upon acceptable responses and scores before scoring
12. Identify candidates by number
13. Employ multiple, independent scoring
Reliability and Validity

A reliable test is not always valid and
viceversa.

WHY?

http://www.youtube.com/watch?v=5lG3R6-4T3k
Effects of the test on students

WASHBACK
Kinds of Washback

POSITIVE WASHBACK

NEGATIVE WASHBACK

Encourages students
Clarifies concepts
…

Makes students nervous, anxious
Makes teachers/ students ignore
«unimportant» topics
…
http://tapchi.vnu.edu.vn/nn_4_09/b.8.pdf
Tips for achieving beneficial washback
1. Test the activities whose development you
want to encourage
2. Sample widely and unpredictably
3. Use direct testing
4. Make testing criterion-referenced
5. Base achievement tests on objectives
6. Ensure the understanding of the test
7. Provide assistance if necessary
VALIDITY,
RELIABLILITY,
WASHBACK
Carolina Salazar
17.02.2014

Validity, reliablility, washback