Optical Mark Recognition (OMR) is the technique used to scan a marked paper to detect the presence or absence of the mark in a predetermined position. The OMR reader illuminates a beam of strong light onto the paper for recognizing the marks. The contrasting reflectivity at the predetermined positions is then utilized to detect the marked positions on the paper. The marked areas reflect less light compared to the blank or unmarked areas. If the darkening of bubbles is not perfect or incomplete, the Reader fails to identify the marks and leave the areas as unmarked.
The most important use of OMR is the detection of pencil marked bubbles in optical answer sheets used in Multiple Choice Question (MCQ) examinations. The personal information of the candidate is marked in the data part of the OMR by darkening the appropriate circles. Similarly the answers are also marked by bubbling the suitable circles in the preprinted answer sheet. The OMR reader scans the answer sheet to recover the data and answers. The answer sheets are then graded automatically by the OMR reader. Even if you mark the correct position, if the marking is incomplete, you will not get the score due to error reading.
The OMR technique was the transition between the old punched card system and the modern bar coding system. Besides the use of examination works and data collection, the OMR is used by commercial agencies and health care agencies to streamline the data input process .In the past, OMR required special kind of paper to mark the data but now the progress in technology allows the users to create their own format to read in the OMR reader.
OMR technology is widely used in applications like Institutional research, community surveys, consumer surveys, examinations, data compilation, product evaluation etc. But there are some disadvantages in OMR system. If the user wants to record large quantity of data, then OMR complicates the process of data collection. Moreover, missing of data, error reading in marks which are not properly marked, etc also occurs during OMR reading.OMR device is thus useful to collect minimum data in a short period of time.
It is the computer software that helps to process datas obtained from surveys, examinations etc. using a computer and an image scanner. By using the OMR software, it is easy to design the OMR format and print the OMR sheets in laser printers. Some of the open source OMR software includes queXF, Udai OMR, Shared Questionnaire Quiz OMR etc.