To calculate the level of difficulty of the test in form of essay according to Anas Sudijono 2011: 134 must be done the steps as
follows: a
Calculate the average score for each item with the formula:
b Calculate the level of difficulty using the formula:
c Compare the level of difficulty with hardship criteria
d Make interpretation of difficulty level by comparing coefficients
with the difficulty level criteria.
4. Distinguishing Power
According to Anas Sudijono 2011: 385, distinguishing power is the ability of an item of achievement test to be able to distinguish
between the testee with a high and low capability. Knowing the distinguishing power was very important, because as one of the handles
to arrange the item of achievement test is the notion that the ability of one testee are different from another testee. Moreover, achievement test
item must be able to provide test results which reflect the differences in ability among the testee.
Distinguishing power of an item can be determined by looking at the number of the index discrimination of an item. The number of item
discrimination index is a number that indicates the number of the
distinguishing power owned by a question. Similarly, by analyzing the level of difficulty, in analyzing the distinguishing power of the question
in the form of objective and essay is done in different ways. All the participants of the tests are grouped into 2 groups, upper
group and lower group. After divided into two groups, distinguishing power can be calculated using the following formula:
Notes: D
= distinguishing power
= number of participants in upper group who
answered questions correctly =
number of participants in upper group who answered questions incorrectly
J =
number of test participants =
number of participants in upper group =
number of participants in lower group =
proportion of participants in upper group who answered questions correctly
= proportion of participants in lower group who
answered questions correctly Suharsimi, 2013: 228
Classification of distinguishing power are as follows: D = 0,00 - 0,19 = poor
D = 0,20 – 0,39 = satisfactory
D = 0,40 – 0,69 = good
D = 0,70 – 1,00 = excellent
Suharsimi, 2013: 232 The higher coefficient of distinguishing power of a test item, the
more ability of test item to distinguish students who master the material with students who did not master the material.
5. Pattern of Answer Distributions
