Bubble sheet generator: printable answer sheets

A bubble sheetBubble sheetA bubble sheet is a printed form on which the candidate fills in, for each question, the bubble or box matching their choice instead of writing an answer. Designed for optical mark recognition, it aligns the answer areas on a regular grid framed by registration marks, which let the software find every box even when the sheet comes out of the scanner slightly rotated or shifted. It can be separate from the question paper, with one sheet for all the questions, or built into it, with the boxes printed under each question. The term is American in origin, popularised by the optical readers that made the format standard in US schools.See the full definition is a grid on which a candidate fills in one bubble per question instead of writing the answer out. The questions stay on their own pages; the grid carries nothing but numbers and letters. That separation is what makes marking mechanical: a marker, or a machine, only has to see which bubble is filled, and never has to read handwriting.

It is also what makes the sheet reusable. The same fifty-question grid serves every fifty-question test of the year, whatever the subject. One layout to approve, one print run to order, and the questions can change up to the night before.

You will also see it called an answer sheet, a test answer sheet, an exam answer sheet or a scan sheet. This generator makes the grid, not the test: the questions stay yours, in the word processor you wrote them in.

Three settings decide whether a printed sheet can still be read by a scanner, and only one of them is routinely wrong. In the print dialog, set the scale to 100 percent rather than to Fit to page. That setting, on by default in a great many drivers, shrinks the sheet by a few percent and moves the corner marks with it.

The second is the paper. The sheet is produced at the size chosen in the options, Letter or A4, and the printer tray has to hold the same. Printing a Letter sheet on A4 works, but the sheet is repositioned and the margins are no longer the ones it was laid out with.

The third is colour, and the answer is that you do not need any. The sheet has no colour fills at all, only black rules and light grey letters inside the bubbles, so black and white is both sufficient and cheaper. Use plain white paper, 20 lb or 24 lb, and avoid heavily recycled stock: the contrast between an empty bubble and a pencil mark is what gets read later.

It depends on two things: the number of answers per question, which sets how wide a column is, and the height of the header block, which sets where the grid starts. The generator picks the smallest number of columns that fits the height available, then shares the questions between them. In practice that means twenty questions give you one column, not four stubs side by side.

What it never does is shrink the bubbles to gain a row. A smaller bubble is a bubble a scanner stops recognising, and the problem shows up six weeks later, silently. Past the point where one sheet is not enough, the grid runs onto a second page and says so.

A sheet made here is not a ScantronScantronScantron is originally an American brand of optical readers and answer forms whose name has become a generic term: in the United States, "a Scantron" commonly means the bubble sheet itself. The system pairs a proprietary pre-printed form with a dedicated machine that reads it. Used generically, the word covers any device that grades multiple-choice exams by optical mark recognition; used as a brand, it names the company and its products. Outside the United States, "Scantron machine" is often shorthand for "MCQ grading machine", including for solutions that work with an ordinary scanner.See the full definition form and cannot stand in for one. Scantron forms are proprietary pre-printed stock, bought by the box, on a paper and with a mark geometry the brand's readers expect. A Scantron reader will not read this sheet, and it should not be asked to: it was not made for it.

What is true is that this sheet does the same job without the form to buy. It prints on plain white paper from any printer, and it is read back afterwards with a scanner or an office copier, with no dedicated reader in the loop. That is the difference between a consumable and a file.

We claim no compatibility with any other vendor's form, and Papeez reads no proprietary form. What Papeez reads is the sheets it laid out itself, and the ones made here, whose geometry it knows.

Once the papers are collected, they still have to be read. By hand, with a punched answer key laid over each grid, a pile of thirty takes a good hour; the hard part is not reading a sheet, it is reading it thirty times without slipping a row.

The four black squares printed in the corners of every sheet are there for the other route. They tell a scanner how the page went through it: how far it drifted, how far it rotated, how much the copier rescaled it. Without them a scanned sheet is a photograph of bubbles and the rest is guesswork; with them the same sheet is an input file.

That is what Papeez does with them: you scan the pile on the copier down the hall or with a phone, it reads the filled bubbles, applies your marking scheme and returns the grades and the per-question statistics. The anonymity barcodeAnonymity barcodeAn anonymity barcode is an identifier printed on each paper that links it to a candidate, or to a version of the exam, without showing any name in clear. The software reads it at scan time, which lets it match the paper to the right person and the right answer key automatically and detect duplicates. The candidate's name stays off the graded image, which keeps the marking anonymous. One barcode per paper also makes it possible to print a unique paper per candidate. Depending on the software, the identifier is printed in advance from the enrolment list or copied by the candidate into a dedicated area. Papeez prints a unique barcode on every paper.See the full definition, whose area you can reserve here with a checkbox, is used at that moment: it ties an anonymous paper back to its candidate without anyone writing a name.