Page 311 - DEDU504_EDUCATIONAL_MEASUREMENT_AND_EVALUATION_ENGLISH

Unit 26: Achievement Test: Concept, Types and Construction

Notes
R H – R L
DP =
N
It is considered suitable to select the items from .3 to .7 difficulty level and about .5
discriminating power. The decision regarding selection of each item used in the test is
displayed by writing yes or no in the last column.
Item Number of students Difficulty Discriminating Suitability
number correctly solving level (DL) Power (DP)

R H + R L R H – R L
R R L 2N N Yes/No
H

Special Mention

At present, generally three types of questions are asked in the achievement tests—essay type, short
answer-type and objective type questions. These questions are selected on different basis.
1. Analysis of Essay Type Questions (Items) : The marks should be adequately divided on the
basis of recall, logic and analysis. It should be made clear in the instructions that the division
of marks should be on the basis of division of marks given in the model answers. Only then
some objectivity can be brought in the evaluation of essay type questions. The following
procedure should be followed in selection of these questions (items) :
(1) The test should at first be administered on a representative sample of students.
(2) Then the calculation of the obtained scores of each student on the essay type questions be
done.
(3) Then the percentage of the obtained scores of the essay type questions be calculated on
the basis of total obtained scores.
(4) The questions on which the candidates secure less than 10% or more than 90% marks
should be left out. Rest of the questions should be selected with due analysis (on the
basis of the blue print). In our example, two essay type questions have to be selected. For
it, 4 questions should be constructed. One question should be selected out of the questions
10% to 20% scores and the other, out of the questions between 50% and 80% scores.
2. Analysis of Short Answer Type Questions (Items): Construction and marking of short answer
type questions should be done on the basis of suitable instructions. Then the similar procedure
should be applied as for the selection of essay type questions. The questions in required
number should be selected with scores between 10% and 80%.
3. Analysis of Objective Type Questions (Items) : The difficulty level arid discriminating power
of these type of questions are known by statistical methods, and the questions are selected
accordingly. For it, the following procedure is adopted :
(1) The test is at first administered on a representative sample.
(2) The obtained scores of each student is calculated.
(3) The answer-books are put in descending order on the basis of obtained scores.
(4) High group and low group are selected on the basis of 27% of the top and bottom
respectively, and the answer books in the middle of these figures are left out. The
number of answer-books of each level is displayed by n. If the test was administered on
100 students, then out of answer-books put in descending order on the basis of obtained
scores, 27 from the top and 27 from the bottom are selected. So the value of n will be 27.
(5) After this, RH (the number of right questions by the higher group) and RL (the number
of right questions by the lower group) are found out.

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