On exams with Multiple Answers to a single question.

Standard exams are generated to have only a single correct answer to each question. Standard mark-sense forms allow five choices for the answer. For certain types of questions, it may be beneficial to generate instead an exam in which multiple answers are allowed for each question. An example would be a problem with five independent statements given, with instructions to mark all the statements that are true. The multiple-answer option allows 31 possible answers, assuming all blanks is not a valid option.

The department maintains the capability to scan in multiple-answer exams with the standard gread
software. The procedure is described in  http://www.physics.rutgers.edu/computers/greadMK.html. The department does not maintain standard grading software for these exams.

As noted in item 5 of http://www.physics.rutgers.edu/computers/greadMK.html: "(If your exam allows multiple answers to a question, type "m" instead of "c")." This option allows scanning in of exams with multiple answers to each question.

The only other difference in scanning in multiple-answer, as opposed to single-answer,  exams is what to do when there is a problem in the scanning,  such as a misfed paper,  a doubly marked column, or a missing exam code. In general in reaction to these problems gread prints out an error message instructing you to enter "s" to stop, or to prepare the scanner and enter "c" to continue, as discussed in items 6 and 7 of http://www.physics.rutgers.edu/computers/greadMK.html. For multiple-answer exams, after entering multiple-answer mode by typing "m", you must respond to the error condition by either typing "s" to stop, or by preparing if needed the mark-sense reader and typing "m" to continue.

The remaining difference between multiple- and single-answer modes is the way the answers are encoded in the gread output file. For single-answer mode, bubbles A - E are encoded as the numbers 1 - 5 (no answer is encoded as a 0). For multiple answer mode, the numbers are encoded as presented below.

  A sample scantron sheet image shows all possible answers:
scantron image
The gread output file for this sheet is:
MULTI                 01  987654321888   8881248G359H6AICKO7BJDLPEMQSFNRTUV
The derived code table is (first going down, then across.) (x/- indicate marked/open bubbles):
Going down:
#marked 1        2         3        4   5
A   : x---- xxxx------ xxxxxx---- xxxx- x
B   : -x--- x---xxx--- xxx---xxx- xxx-x x
C   : --x-- -x--x--xx- x--xx-xx-x xx-xx x
D   : ---x- --x--x-x-x -x-x-xx-xx x-xxx x
E   : ----x ---x--x-xx --x-xx-xxx -xxxx x
Going across:
x---- 1
-x--- 2
--x-- 4
---x- 8
----x G
xx--- 3
x-x-- 5
x--x- 9
x---x H
-xx-- 6
-x-x- A
-x--x I
--xx- C
--x-x K
---xx O
xxx-- 7
xx-x- B
xx--x J
x-xx- D
x-x-x L
x--xx P
-xxx- E
-xx-x M
-x-xx Q
--xxx S
xxxx- F
xxx-x N
xx-xx R
x-xxx T
-xxxx U
xxxxx V 

Created 11/30/2009  R. Gilman