Evaluation skillsExplainer

Multimodal AI Evaluation: Text, Image, Audio and Video

Review outputs against the image, audio or video evidence they depend on, with attention to timing, visibility and cross-modal consistency.

4 min read · Published September 9, 2026

You'll learn

  1. Judge the relationship between the output and the supplied media.
  2. Separate what is visible or audible from what you infer.
  3. Timestamps, spans and frame references make findings checkable.
  4. Video and robotics-related tasks require attention to sequence and uncertainty.
In this guide
  1. What changes with the medium
  2. A timeline can contradict a fluent summary
  3. Unclear evidence is part of the task
  4. Make findings easy to locate

A caption can be grammatical and still describe an object that is not in the image. A transcript can read naturally while dropping a spoken “not.” A video summary can mention all the right actions in the wrong order. In each case, language quality alone misses the defect.

Quick definitionMultimodal evaluation
Assessing a system that takes or produces more than one kind of information, such as text, images, audio or video. The review may concern each modality and the relationship between them.
Quick definitionGrounding
The connection between an output and the evidence it is supposed to represent. A grounded statement points to what the supplied material actually supports.

What changes with the medium

Evidence by medium
MediumTypical reviewEasy-to-miss defect
ImageCaption accuracy, object attributes, text recognition or spatial relations.Describing an obscured object as if its identity were certain.
AudioTranscript fidelity, speaker turns or requested speech qualities.Removing a negation or assigning words to the wrong speaker.
VideoEvents, order, timing and interactions.Claiming a later action caused an earlier event.
Document imageExtracted text, tables and layout-dependent meaning.Attaching a value to the wrong row or ignoring a footnote.
Robot or action footageVisible motion, object interaction and task completion.Inferring an object was securely grasped from a single frame.

A timeline can contradict a fluent summary

Evaluation example

Prompt
Illustrative video task. The supplied event log describes a synthetic clip: 00:02, a person places a mug on a table; 00:05, the person leaves; 00:08, the mug falls. Summarize only the observable sequence.
Response A
The person knocks the mug off the table before leaving.
Response B
The person places the mug on the table and leaves; the mug falls afterward.
Decision
Response B
Why
B preserves the event order. A invents contact and puts the fall before departure. The example uses an explicit fictional event log rather than claiming an unseen clip was inspected. In a real task, attach the relevant timestamps or frames required by the project.

Unclear evidence is part of the task

If speech is masked by noise, use the project’s convention for uncertain or inaudible content. If text is too small to read, do not fill it in from what would make sense. If an object leaves the frame, distinguish “not visible” from “removed.” These distinctions preserve the limits of the input.

Review the permitted media at the available resolution and playback controls. A thumbnail may hide text that the full image reveals. A still frame cannot establish an action sequence. At the same time, do not claim to have used magnification, audio replay or a full-resolution file if those were unavailable.

Reality check

The assumption

If the output sounds plausible, it probably matches the media.

The reality

Plausibility can conceal invented detail. Compare the claim with the relevant region, segment or sequence. When the evidence is ambiguous, preserve that ambiguity instead of guessing a more satisfying description.

Make findings easy to locate

Name the output phrase and the source location that conflicts with it. For a transcript, give the relevant span or timestamp. For a table extraction, identify the row and column. For video, distinguish an event boundary from a whole-clip judgment. Follow the annotation conventions supplied by the project rather than inventing incompatible labels.

Key takeaway

The review should preserve what the media shows, including what it does not let you know.