Item Analysis.pptx

8/14/2019 Item Analysis.pptx

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ANALYZING AND

INTERPRETING OF

TEST ITEMS

LEONCIO P. LUMABAN, Ph.D.

Education Program Supervisor II


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Meaning of Numbers

Numbers ascodesfor labeling purposes(nominal)

1= girl 2=boy

1= RURAL 2= URBAN

1=PGMA 2=RR 3=EV 4=PL 5=FPJ

1 = 11 2

Stud

No.

Gender Location Choice

1 1 1 1

2 2 2 1


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Meaning of Numbers

Numbers ascodesfor labeling purposes(nominal)

1= girl 2=boy

1= RURAL 2= URBAN

1=PGMA 2=RR 3=EV 4=PL 5=FPJ

1 = 11 2

Stud

No.

Gender Location Choice

1 1 1 1

2 2 2 1

What can you infer from the data givenon table below?


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Application in the classroom

Numbers to label

categories

1 = Fail

2 = Pass

3 = Advanced level

2 = Intermediate

1 = Beginning

Frequency distribution

by group

Stud.

No

Lang

Prof

Grade

1 2 2

2 1 1

3 3 2

N 1 1


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Application in the classroom

Numbers to label

categories

1 = Fail

2 = Pass

3 = Advanced level

2 = Intermediate

1 = Beginning

Frequency distribution

by group

Stud.

No

Lang

Prof

Grade

1 2 2

2 1 1

3 3 2

N 1 1

Based on the table, when do you fail orpass a student?


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Numbers asarbitrary measuresfor

indicating amount or degree based onan arbitrary zero point (interval)

Math = 60

Attitude Scale = 25

temperature = 30 degrees

0 n

0

If your score is zero in ameasuring instrument thatis in interval scale, how

will you interpret it?


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Numbers astrue measures

indicating

measures using scales with true zero

point ( ratio)

5 meters

3 kilos

true numerical scales

0 n


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Numbers astrue measures

indicating

measures using scales with true zero

point ( ratio)

5 meters

3 kilos

true numerical scales

0 n

If your score is zero in a measuring

instrument that is in ratio scale, howshould you interpret it?


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Test Results Raw scores

Raw score(RS)numerical summary of astudents test performance

number of items correctly answered ( one

correct item gets one point)30correct items out of 50items

number of points received on a test ( regardless

of the number of points given to an item/task)30points out of 50possible points

( Each task = 10 max points)


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Some assumptions prior to analysis..

Scores are coming from good tests!

A good test consists of good items!

What is a good item?

Measures a significant learning outcome.

(CONTENT VALIDITY)

Discriminates between one who knows and one who

doesnt know; between high-achieving and low-

achieving (CONSTRUCT VALIDITY)

Distracters effective (multiple-choice items)


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ITEM ANALYSIS for Summative

Tests (norm-referenced perspective)

Item analysis is good for planning future norm-

referenced tests

Can be used for instructional purposes

I-A data provide basis for efficient class discussion ofthe test results

I-A data provide a basis for remedial work

I-A data provide a basis for the general improvement

of classroom instruction

I-A procedures provide a basis for increased skill in

test construction


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Ability to Discriminate It should not be very easyevery one will get it!

It should not be very difficultNo one will get it!

Simplified I-A procedures

Classroom

Compare the performance of the highest-scoring

students and the lowest-scoring students Large classtop ten vs bottom ten

Small classtop half vs bottom half


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Sample Item Analysis Data

Item CardSubject: _____________ Unit: WeatherObjective: Identifies use of instruments

Item:Which of the following is most useful in

weather forecasting?A. Anemometer

* B. BarometerC. ThermometerD. Rain gauge


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Sample

Group A B C D

U-10

L-10

1

2

8

4

0

1

1

3

(Back of item card)Item Analysis Data

Diff.Index

DiscIndex

.60 0.40

1


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Sample

Group A B C D

U-10

L-10

1

2

8

4

0

1

1

3

(Back of item card)Item Analysis Data

Diff.

Index

Disc

Index

0.60 0.401

How was the difficulty/discrimination indexcomputed?


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Indices:

Difficulty Index = No. of students in upper group

getting item correct + No. of students in lower group

getting item correct/ total no. of students who took the

test

p = RH + RL

N

Discrimination Index = No of students in upper group

getting item correctNo of students in lower group

getting item correct / of the no. of students who

took the test

r = (RHRL)

Ng


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Where R = # of correct responses

H = high group

L = low group

N = # of students

g = size or # of students in either high/low group

Difficulty (p) indices Discrimination indices0.91 - 0.95 very easy 0.40 or higherVery Good Item0.76 - 0.90 easy 0.300.39 - Good Item0.25 - 0.75 average 0. 200.29 - Reasonably Good Item0.100.24 difficult 0.10- 0.19 Marginal Item0.050.09 very difficult Below 0.10- Poor Item

I h di i f h l f h i l i


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In the discussion of the results of the item analysis,the item needs to be revised or rejected when:

Almost all in both groups are able to answer theitemBoth groups find the item too difficult such thatalmost none are able to answer the item correctly

When a negative d is obtained (i.e., more in thelow group answered the item

Additional information to help you decide which

items to eliminate from a test, before it is againadministered is to analyze the distractors or options.


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Poor distractorSome distractors are not chosenat all by all students in the upper group.

Example : A B C D*4 0 0 9


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ITEM improvement and selection

Guidelines:1. Consideration based on difficulty index and

discrimination index

Discrimination Index Difficulty Index0.24 or lower 0.250.75 0.76 or higher

0.40 and above (Very Good item) Difficult Acceptable Easy

0.300.39 (Good item) Difficult Improvable Easy

0.200.29 (Reasonably Good item) Difficult Marginal Easy

0.10 -0.19 (Marginal Item)

Below 0.10 (Poor item)Rejected Rejected Rejected

(Kept for Mastery)

Item Analysis.pptx

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