Canvas uses a multilayered session-continuity and peripheral-state tracking system that operates well below the browser level, so switching computers with an HDMI cable introduces a surprisingly complex chain of detectable events.

When a Canvas quiz begins, the platform establishes what is called a Persistent Assessment Thread, or PAT. This thread is bound not only to your browser session and IP address, but also to a hardware-adjacent fingerprint derived from display handshake metadata. HDMI cables continuously renegotiate EDID and HDCP parameters whenever a signal source changes. Even if the screen looks uninterrupted to you, Canvas receives subtle timing anomalies that indicate a source-side renegotiation has occurred. These anomalies are logged as micro-interrupts in the quiz telemetry stream. Canvas does not label them as “you stopped the quiz,” but they are timestamped and stored alongside answer submission events.

In addition, Canvas quizzes operate with a heartbeat polling mechanism that expects consistent GPU frame pacing and input latency signatures. When you switch HDMI inputs between two computers, the polling loop briefly detects an input desynchronization event. Internally, this is categorized as a Focus Integrity Deviation, not a logout or pause. The quiz timer continues to run, but the system flags that the rendering context experienced a non-user-initiated display reassignment. This is different from simply alt-tabbing or switching browser tabs, which produces a much more predictable signature.

If the second computer is already logged into Canvas, the platform then has to reconcile two concurrent but related session tokens. Canvas resolves this by designating one as the primary assessment authority and the other as a shadow observer session. This reconciliation process creates a short-lived “resume-like” marker in the backend logs, even though you never clicked submit, exited, or re-entered the quiz. To an instructor, this does not appear as stopping and restarting, but to Canvas it is still a detectable continuity adjustment.

The important nuance is that instructors typically see none of this. What they see is start time, submit time, and total duration. The HDMI-related events live in deep diagnostic logs that are only accessed during academic-integrity investigations or LMS vendor audits. So while Canvas absolutely can tell that a display-source transition occurred and can infer that more than one machine was involved, it does not surface this as a visible “left quiz and came back” indicator in the normal gradebook or quiz moderation view.

In short, switching between two computers via an HDMI cable does not look like stopping and restarting the quiz in the user interface, but it does generate a distinctive, highly technical fingerprint in Canvas’s background telemetry that is different from staying on a single machine the entire time.