ITEM ANALYSIS AND

VALIDATIONReported by:AGUSTIN, Levin Jasper A.BSE – E – 3 (Irreg.)

Draft subjected to Item Analysis and

Validation

PHASES

(1) try-out phase(2) Item analysis phase (level of difficulty)(3) Item revision phase

ITEM ANALYSIS

Two important characteristics:

(a)item difficulty(b)discrimination index

Item difficulty = number of students with correct answer/ total number of students

The item difficulty is usually expressed in percentage.

Range of Difficulty Index

Interpretation Action

0 – 0.25

0.26 – 0.75

0.76 – above

Difficult

Right difficulty

Easy

Revise or discard

Retain

Revise or discard

Index of Discrimination

Tells whether it can discriminate between those who do not know the answer

Difficulty in: Upper 25% of the class Lower 25% of the class

Formula: DU - DL

Index Range Interpretation Action

-1.0 - -.50

-.55 – 0.45

0.46 – 1.0

Can discriminate but

item is questionable

Non-discriminating

Discriminating item

Discard

Revise

Include

Index of Difficulty the proportion of the total group who

got the item wrong

FORMULA:

P = RU + RL X 100T

RU – The number in the upper group who

answered the item correctly

RL – The number in the lower group who

answered the item correctly

T – The total number who tried the item

VALIDATIONPURPOSE: to determine the characteristics of the whole test itself, namely, the validity and reliability of the test

VALIDITY - Is the extent to which a test measure or as referring to the appropriateness, correctness, meaningfulness and usefulness of the specific decisions a teacher makes based on the test results

Three Main Types of Evidence that may be collected:

Content-related evidence of validity

Criterion-related evidence of validity

Construct-related evidence of validity

Expectancy Table

GRADE POINT AVERAGE

Test Score

High

Average

Low

Very Good

20

10

1

Good

10

25

10

Needs Improveme

nt

5

5

14

RELIABILITY

refers to the consistency of the scores obtained

RELIABILITY INTERPRETATION

.90 and aboveExcellent reliability; at the level of the best standardized tests

.80 - .90Very good for a classroom test.

.70 - .80Good for a classroom test; in the range of most. There are probably a few items which could be improved.

.60 - .70

Somewhat low. This test needs to be supplemented by other measures (e.g., more tests) to determine grades. There are probably some items which could be improved.

.50 - .60

Suggests need for revision of test; unless it is quite short (ten or fewer items). The test definitely needs to be supplemented by other measures (e.g., more tests) for grafing

.50 or belowQuestionable reliability. This test should not contribute heavily to the course grade, and it needs revision.