The document discusses the item analytic approach to test construction. It defines key terms like test, construction, and item analysis. It explains that the item analytic approach involves analyzing items on a test to evaluate their characteristics like difficulty level and discriminating power. Items are analyzed based on responses from high-scoring and low-scoring groups. Items are then selected or rejected for inclusion in the final test based on whether they meet pre-determined criteria for difficulty and discriminating power. The document provides formulas for calculating difficulty value and discriminating power and illustrates the process with an example of item analysis conducted on a Likert scale test.

1. Item analytic approach
to test construction
Dr. Girish Kumar Tiwari

2. The title comprises of eight key terms:
 Test
 Construction
 Test
Construction
 Approach
2
 Approach to Test
Construction
 Item
 Analytic
 Item Analytic

3. Test -
There are several definitions :
Test is defined as a series of questions
on the basis of which information is
sought.
3

4. According to Meriamm- Webster Dictionary,
A test or examination (informally, exam or
evaluation) is an assessment intended to
measure a test-taker's knowledge, skill,
aptitude, physical fitness, or classification in
many other topics (e.g., beliefs).
4

5. A psychological test is an objective and
standardized measure of sample of behavior.
As per the words of Smith, Greggory
(2003) A psychological test is an
instrument designed to measure unobserved
constructs, also known as latent variables.
5

6. According to Mellenbergh, G.J. (2008) A
psychological test is a standardized
measure quantitatively or qualitatively
one or more than one aspect of trait by
means of a sample of verbal or non-
verbal behaviors.
6

7. Construction -
-Process of creating or developing something
7
Test Construction -
-Process of creating or developing a test in
general or a psychological test in particular

8. 8
-Test construction is the set of activities involved in
developing and evaluating a test of some psychological
function. The steps include specifying the construct of
interest, deciding the test’s function (diagnosis,
description of skill level, prediction of recovery), choosing
a method (performance, behavioral observation, self-
report), designing item content, evaluating the
reliability and validity of the test, and modifying the
test to maximize its utility.

9. Steps of test construction
 Planning the test
 Preparing the items
 Selecting the items
 Evaluating the test
9

10. Approaches of test construction:
There are three commonly used approaches of test
construction:
 Inductive approach;
 Deductive approach; and
 Empirical approach

11. Inductive Approach:
The inductive method begins by constructing a wide variety of items
with little or no relation to an established theory or previous
measure. The group of items is then answered by a large number of
participants and analyzed using various statistical methods, such as
exploratory factor analysis or principal component analysis. These
methods allow researchers to analyze natural relationships among
the questions and then label components of the scale based on how
the questions group together. The Five Factor Model of personality
was developed using this method.

12. Deductive Approach:
Also known as rational, intuitive, or deductive method. The
deductive method begins by developing a theory for the construct
of interest. This may include the use of a previously established
theory. After this, items are created that are believed to measure
each facet of the construct of interest. After item creation, initial
items are selected or eliminated based upon which will result in the
strongest internal validity for each scale.

13. Empirical Approach:
Also known as External or Criterion Group method. Empirical test
construction attempts to create a measure that differentiates
between different established groups. For example, this may include
depressed and non-depressed individuals, or individuals high or low in
levels of aggression. The goal of item creation is to find items that
will be answered differently by the groups of interest. Items are
traditionally constructed without expectation for how they will be
answered by each group. The Minnesota Multiphasic Personality
Inventory was initially developed using this method.

14. “This method primarily differs from the inductive
method in the way items are selected. While
inductive methods select items based upon factor
loadings, empirical items are selected based upon
validity coefficients and their ability to accurately
predict group membership.
14

15. Here, in this approach the test developer go
through the item analysis to select or reject
items. So, it is also known as item analytic
approach of test construction. And this is our
concern for today.
15

16. Item analysis is the set of qualitative
and quantitative techniques and
procedures used to evaluate the
characteristics of items. Item analysis
allows selecting or omitting items from
the test.
Item Analysis -
16

17. Difficulty level of an item is the difficulty
of a question from student points of view
and discriminating power is the extent
up to which an item discriminates among
the groups of test takers.
Difficulty Value & discriminating power-
17

18. Difficulty Value
• 𝐷. 𝑉. = 100 −
𝑅𝐻+𝑅𝐿
2𝑛
×
100
• Here, D. V. = Difficulty
Value;
• RH = Number of Right
Responses in High Scorer Group;
• RL = Number of Right
Responses in Low Scorer Group;
and
• n = Number of
respondent in high or low group
= 81
• The highest D.V. of an item
means the item is easiest
18

19. Discriminating Power
• D. P. =
RH−RL
n
• D.P. =
Discriminating Power;
• RH = Number of Right
Responses in High Scorer Group;
•
• RL = Number of Right
Responses in Low Scorer Group;
and
• n = Number of
respondent in high or low group
= 81
19

20. Other Formula for D.V. and D.P.
• 𝐷. 𝑉. = 1 −
𝑃𝐻+𝑃𝐿
2
• Here, D. V. = Difficulty Value;
• PH = RH/n;
• PL = RL/n
• n = Number of respondent in
high or low group
• The highest D.V. of an item
means The item most difficult.
• D. P. = PH − PL
• Here, D.P. = Discriminating
Power;
• PH = RH/n;
• PL = RL/n
• n = Number of respondent in
high or low group
20

21. Desired Value of D.V and D.P.
 The difficulty value of the items for retaining in the test should lie
between 30% to 80% (Oosterhof,1990).
 The discriminating power for same should range between 0.30 to 0.80
(Oosterhof,1990).
21

22. 22
Item No. RL RH D.V. D.P. Decision
1 32 71 36.41975 0.481481 *S
2 17 44 62.34568 0.333333 *S
3 14 60 54.32099 0.567901 *S
4 12 62 54.32099 0.617284 *S
5 10 35 72.22222 0.308642 *S
6 17 47 60.49383 0.37037 *S
7 5 30 78.39506 0.308642 *S
8 10 59 57.40741 0.604938 *S
9 14 58 55.55556 0.54321 *S
10 13 38 68.51852 0.308642 *S
11 8 33 74.69136 0.308642 *S
12 8 33 74.69136 0.308642 *S
13 12 46 64.19753 0.419753 *S
14 5 30 78.39506 0.308642 *S
15 6 12 88.88889 0.074074 **R
16 5 31 77.77778 0.320988 *S
17 17 40 64.81481 0.283951 **R
18 12 25 77.16049 0.160494 **R
19 4 29 79.62963 0.308642 *S
20 17 45 61.7284 0.345679 *S
21 9 34 73.45679 0.308642 *S
22 24 30 66.66667 0.074074 **R
23 15 28 73.45679 0.160494 **R
24 9 35 72.83951 0.320988 *S
25 11 36 70.98765 0.308642 *S
26 12 19 80.8642 0.08642 **R
27 7 32 75.92593 0.308642 *S
28 14 36 69.1358 0.271605 **R
29 11 36 70.98765 0.308642 *S

23. Item analysis of Likert Type Scale
• After scoring, the researcher went through the process of item
analysis. The literature on behavioural statistics suggested about
several methods of item analysis. Some were highly restricted in its
applicability, while others can be used almost universally.
23

24. In any Likert Type Scale only discriminating power is calculated for item
analysis. ‘t’-test’ will be used for computing the discriminating power.
24

25. Process of Computing Discriminating Power
• Arranged the data into ascending order. The base of arrangement
is the total score obtained by a respondent on the above said tool.
• Calculate the 27 % of the total sample size that is (150x27)/100 =
• 40.5 = 41 in the case of given example.
• Divide the whole respondents into three groups which are low
scorer, high scorer and average.
25

26. • Take only low scorer group and high scorer group
• Thus, a test developer get two set of scores for each item
• Calculate the Mean and S.D. for the each item of each group on the
basis of the score of low scorer group and high scorer group.
• Calculate t-value for each item.
• Check the significance of computed ‘t-value’ at desired level of
significance for desired degree of freedom.
• Take decision to keep the item in test or to withdraw the item from
test.
26

27. 27
I. NO. Mean SD t-value Signif-
icance
Selection/
Rejection
High group Low group High group Low group
01 3.63 2.80 0.94 0.87 4.13 S Selected
02 3.19 2.85 1.64 0.88 1.17 NS Rejected
03 5.00 4.19 0 0.40 12.84 S Selected
04 3.07 2.26 1.58 0.44 3.12 S Selected
05 5.00 2.97 0 1.23 10.49 S Selected
06 3.60 2.12 1.65 0.33 5.63 S Selected
07 4.63 3.48 0.48 0.80 7.76 S Selected
08 4.75 3.80 0.48 0.60 7.86 S Selected
09 4.24 3.12 1.13 0.55 5.68 S Selected
10 2.51 2.09 1.38 0.83 1.64 NS Rejected
11 4.26 2.87 1.11 1.18 5.45 S Selected
12 4.80 4.09 0.40 0.58 6.39 S Selected
13 4.87 3.90 0.33 0.73 7.74 S Selected
14 4.80 4.26 0.40 0.89 3.50 S Selected
15 4.97 3.68 0.15 1.08 7.56 S Selected
16 4.36 4.46 1.13 0.50 0.50 NS Rejected
17 3.29 3.80 1.14 0.60 2.53 NS Rejected
18 5.00 3.90 0 1.24 5.66 S Selected
19 3.92 3.21 1.31 1.57 2.21 NS Rejected
20 4.26 2.92 0.80 0.56 8.71 S Selected
21 4.51 3.31 0.50 1.05 6.51 S Selected
22 3.70 3.58 1.12 0.66 0.59 NS Rejected
23 4.82 3.46 0.38 0.95 8.53 S Selected
24 4.58 2.51 0.49 0.80 13.95 S Selected
25 4.75 3.02 0.48 0.65 13.61 S Selected
26 4.65 4.02 0.48 0.75 4.52 S Selected
27 2.41 3.09 1.18 0.86 2.98 S Selected
28 4.70 3.29 0.46 0.67 11.03 S Selected
29 4.78 4.09 0.41 0.30 8.48 S Selected
30 4.87 3.82 0.33 0.58 9.95 S Selected
31 4.70 4.78 0.46 0.41 0.75 NS Rejected
32 4.87 4.04 0.33 0.77 6.31 S Selected

28. 28
Thank you
Dr. Girish Kumar Tiwari
Project Fellow – I
Inter University Centre for Teacher Education,
Banaras Hindu University, Varanasi
Mob. – 7318248269
Email: - girishtiwari8@gmail.com