Description of Terminology Used in the
Test Statistics and Item Analysis Section of the Exam Scoring Report
TEST STATISTICS
Position
Header
ROW 1
ROW 2
ROW 3
Test Name
Test Date
Number of
Examinees
Number of
Items
Maximum
Possible
Points
Highest
Score
Lowest Score
Median
Mean
ROW 4
ROW 5
ROW 6
ROW 7
ROW 8
ROW 9
ROW 10
ROW 11
ROW 12
Page 1 of 2
Description
The number of students taking the exam.
The number of items included in the test.
The maximum raw score value a student can receive. This value may
exceed the number of item values if some items are ‘weighted’ more
than 1.
The highest score on the exam (percent).
The lowest score on the exam (percent).
The median of the scores earned by students taking the exam (percent).
The mathematical average of the scores earned by students taking the
exam (percent).
Standard
The standard deviation of the scores earned by students taking the
Deviation
exam.
Test
A measure of internal consistency of the exam. Can be taken as a lower
Reliability
bound estimate of the reliability of scores of the exam.
Standard
Provides an estimate of how far the true score may lie from the
Error of
observed score for an average examinee in the group. The standard
Measurement error of measurement (SEM) is a function of the standard deviation of
the score and the test reliability. In practice SEM is used to calculate
the upper and lower limits of student’s score where his/her true score is
assumed to be located.
Revised 12/2004
ITEM STATISTICS
Position
Header
Column 1
-----Item
Column 2
– including
headers
which will
read across
the rows
Overall
Admins
p
rpb
Description
Item number. If you scan across this row, the correct option statistics
are highlighted in bold.
Total number answering item.
Commonly known as “p-value”, which is the proportion of examinees
answering the item correctly. The “p-value” is used as a difficulty
index of the item. The higher the “p-value” the easier the item. The
lowest possible “p-value” is 0 (very difficult; no examinees answer the
item correctly) and the highest possible “p-value” is 1 (very easy item;
everyone has it correct).
A measure of correlation between a given item and the total score. It
is a special case of the Pearson product moment correlation when one
of the variables is dichotomous (takes a value either 0 or 1).
Point-biserial is used as an index of item discrimination which is a
characteristic of an item that addresses the ability of an item to
measure sensitively individual differences in the domain measured by
the exam. The size of the discrimination index indicates the relation
of the item to the total domain of knowledge – as represented by the
total score.
Zero correlation indicates that the item does not relate at all to the
total domain of knowledge – as represented by the total score.
Meaning that examinees can have the item right (or wrong) regardless
of their overall performance in the entire exam.
Column 3
Column 4
Omits
A (True)
Column 5
Column 6
Column 7
Column 8
B (False)
C
D
E
Page 2 of 2
While a correlation of 1 indicates a perfect relation between the item
and the total domain of knowledge measured by the test, a negative
correlation indicates the reversal – which may be a result of an item
being keyed incorrectly.
Number of students who left this item blank.
Corresponds with option A on the answer sheet. The headers listed
above for column two also apply here: admis or number of students
choosing this option, p or percent of students choosing this item, rpb
or point-biserial of this item. Reminder that the correct answer statistics
are highlighted in bold. So if option A is correct, all stats under this
column are in bold.
Corresponds with option B on the answer sheet.
Corresponds with option C on the answer sheet.
Corresponds with option D on the answer sheet.
Corresponds with option E on the answer sheet.
Pattern continues if using answer sheet with options A-J.
Revised 12/2004