The commonest use of OMR is in the testing process and the most frequently designed OMR sheet has been the OMR Answer Sheet. All OMR Answer Sheets have several things in common while only few things may differ. Given below are some constant components of an OMR Answer Sheet:
Roll No. Block
Test Paper Set or Question Paper Code
Instructions on How to fill the sheet
Signature and stamping boxes for authentication
Area for filling Candidate Personal Information
The above given elements are generic components of an OMR Answer Sheet. But each of these components has quite many variations in presentation and method of operation that gives a different look to each and every OMR Test Sheet design.
Question Blocks: Single Row MCQ Type OMR Blocks having 4 or 5 options like ABCD or ABCDE. Matrix type MCQ questions block having 4 to 5 rows and 4 to 5 columns for each question making a planer block of 4 rows by 4 columns or 4 rows by 5 columns. The third type is the Integer type MCQ question block which quite resembles the Roll No. Block except for the number of columns which is equal to the number of digits expected in the answer.
Candidate Identification Block (Roll Number Block): Each OMR sheet needs a unique identifier block, this is mostly the roll number block in case of OMR Test Answer Sheet Design. This Roll number block is a matrix of OMR bubbles having 10 rows of 10 digits from 0-9 and the number of columns is equal to the length of the roll number. So if the Roll number is a 4 digit Roll number, then a matrix of 10 rows by 4 columns would be required for the candidate to fill such a roll number. But using OMR based matrix to input the roll number is not the only way of getting the unique identifier on the sheet. Many OMR Sheets have pre printed unique identifier blocks in the form of barcodes. These barcodes are pre-printed on the sheet and just need to be read by the inbuilt Barcode reading features of the OMR reader software.
Test Identification Block (Test paper/Set code): This is not an essential component on all the answer sheet designs. Some answer sheets have the field to fill Test Paper Code or Set Code while these filed are totally missing from other Answer Sheet designs. The answer sheets for the test in which there is only one question paper being presented to the students, it is not required to know the test paper code because that single code is already known which can be selected at the time of checking. Set code is included only when there are multiple test papers or a series of shuffled tests in more crucial government recruitment and competitive exams.
Candidate Personal Information fields: In fields like Name, Fathers Name, Gender, Category, Date of Birth, Mobile number, etc. are some of the fields which we commonly find on the OMR Answer Sheets. But these types of fields are usually found on the answer sheets of private organizations, institutions, scholarship and data collection drives. These types of candidate identification fields are generally missing from the answer sheets of crucial examinations where the identity of the candidate is obscured and replaced by a human unreadable Barcode. The purpose of these types of fields is mainly to make provision for a possibility of manual correction of mistakes when the candidate commits a mistake in filling the roll number or other required details on the OMR sheet. This candidate identification field at least helps locate the candidates roll number from the back end list maintained by the institution.
Instruction for Filling the OMR Sheet and Authentication Areas: This is a simple text content which has technically nothing to do with OMR bubble reading. So the contents of the Instruction box and size shape and location of this box on the answer sheet may vary. Similarly some examinations only expect the candidate to sign on his sheet, while most examinations get both the candidate and Invigilators signature. Yet another type of examination sheets has the boxes for signature of candidate, Invigilator and also supervisor and Stamp of the Institute. This leads to various possibilities of design structures of OMR Answer Sheets.