Item Analysis- is done after the first try out of the test.

One method conducting item analysis is U-LIndex Method.

1. The tester score the papers and rank thescores from the highest to lowest according tothe total score.

2. Separate the upper 27% and lower 27% ofthe papers.

3. Tally the responses made to each test item byeach student in the upper 27% then do thesame with the lower 27%.

4. Compute the percentage of the upper groupthat got the item right. This is called the U.

5. Compute the percentage of the lower groupthat got the item right. This is called the L.

6. Average U and L percentage. The result is thedifficulty index

7. Subtract the L percentage from the Upercentage. The result is the discrimination index.

After the item analysis, the tester uses thefollowing table of equivalents in interpreting thedifficulty index:

.00 - .20 - Very Difficult

.21 - .80 - Moderately Difficult

.81 – 1.00 - Very Easy

Item Revision

On the basis item analysis data, testitems are revised for improvement. Afterrevising the test items that need revision,the tester needs another try out. Therevised test must be administered to thesame set of samples.

Third try out

After two revisions, the test isconsidered ready for the final form. The testis good in terms of difficulty index anddiscrimination indices. At this time, the testis ready for it reliability testing.

How to Establish Reliability

Test reliability is an element in testconstruction and test standardization and isthe degree to which a measure consistentlyreturns the same result when repeatedunder similar conditions.

Reliability does not imply validity. Thatis, a reliable measure is measuringsomething consistently, but not necessarilywhat it is supposed to be measuring.

Multiple-administration Method – require thattwo assessment are administered.

1. Test-retest reliability – is estimated as thePearson Product-moment Correlation

Coefficient between two administrations of thesame measure. This is sometimes known as thecoefficient of stability.

2. Alternative forms reliability – is estimated bythe Pearson product moment correlationcoefficient of two different forms of measure,usually administered together. This is sometimesknown as the coefficient of equivalence.

Single-administration methods – include split-halfand internal consistency.

1. Split-half reliability – treats the two halves of ameasure as alternate forms. This “halves reliability“ estimate is then stepped up to the full testlength using the Spearman Brown PredictionFormula. This is sometimes referred to as thecoefficient of internal consistency.

2. The most common internal consistencymeasure is Cronbach’s alpha, which is usuallyinterpreted as the mean of all possible split-halfcoefficients. Cronbach’s alpha is a generalizationof an earlier form of estimating internalconsistency.

Cronbach’s alpha Internal consistency

α ≥ 0.9 Excellent

0.9 > α ≥ 0.8 Good

0.8 > α ≥ 0.7 Acceptable

0.7 > α ≥ 0.6 Questionable

0.6 > α ≥ 0.5 Poor

0.5 > α Unacceptable