How Accurate Are Scantrons?
The Scantron 888P+ model can grade as many as 40 tests per minute with a 99.9% accuracy rate. Scantron forms contain an infrared light-reflecting ink. When a form passes under an internal read head, the machine notes where the light has been absorbed by pencil lead.
Though some scantron issues are human error, the machine itself isn't exactly state of the art. The actual scantron machine has a tendency to mark correct answers as wrong.
Why we shouldn't use scantrons for tests - The Glen Echo
Can Scantrons detect cheating?
If cheating is witnesses, corroborating evidence can be obtained from the scantron data. If a student copies the answers from someone sitting nearby, the two answer vectors may appear suspiciously similar.
In-Class Design Exercise: Scantron Cheating Detection
Scantron is an effective and widely-used multiple-choice testing tool that can be used to save time and energy grading exams.
Scantron - Arts ISIT
How do you cheat on a scantron?
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HOW TO ACE ANY SCANTRON TEST - HIGH SCHOOL HACKS - YouTube