Evaluating Long-Form Video Comprehension with 1,500+ Expert-Annotated Samples

Built a multi-layered dataset of long-video annotation tasks, including complex edge cases such as STEM tutorials, multi-speaker dialogues, and audio-visual synchrony for benchmarking state-of-the-art (SOTA) video understanding models.

1,500+

annotated video tasks covering open-domain and instructional content.

500+

tasks with audio components, including speaker IDs, transcripts, and ambient sound labels.

100%

human-audited segmentation, with dual-pass QA for scene boundaries, caption accuracy, and visual tag coverage.

MethodMultimodal evaluation
DomainVideo comprehension
Dataset scale1,500+ tasks
CapabilityData Packs
Evaluating Long-Form Video Comprehension with 1,500+ Expert-Annotated Samples

The Challenge

Multimodal agents often struggle with long-form video inputs due to unclear scene transitions, mixed audio-visual signals, or dense motion patterns. The client required a dataset that could:

  • Evaluate scene segmentation, audio captioning, and transcript extraction with high temporal resolution
  • Capture foreground motion, camera movement, visual text, and causal relationships
  • Handle STEM domains requiring instructional focus such as math lectures, science experiments, and engineering tutorials
  • Provide a clear reference for agentic evaluation, especially in videos with overlapping sounds, slides, or background distractions

The Approach

Dataset design

Each task consisted of:

  • Global overview for visual and audio context, capturing setting, tone, and speaker structure
  • Context-level segments annotated for overall scene structure and flow
  • Fine-grained segments capturing semantically rich content and moment-specific interactions

Each video was annotated using context-level segmentation for scene structure and fine-grained segmentation for semantically rich moments.

Segment-level annotations:

  • visual_caption: detailed description using the watch → observe → note → draft process
  • visual_text: on-screen text reproduction with exact spelling and timestamps
  • audio_caption: description of ambient audio, speaker tone, or key non-speech sound
  • transcription: verbatim, timestamped speech with speaker IDs and character descriptions

All STEM-related videos were annotated to prioritize foreground instructional content and minimize focus on trivial background details.

Annotation and QA flow

  • Annotators used Turing’s labeling tool integrated with LLM-based preannotation for visual captioning and transcription support
  • 75+ annotators were trained through a structured bootcamp covering segmentation, narrative clarity, and STEM-specific guidelines
  • Implemented dual-layer manual QA to review every sample:
    - Layer 1: scene accuracy, audio-visual alignment, object detail
    - Layer 2: grammar, label correctness, and metadata compliance
  • Programmatic checks were incorporated for segmentation consistency & hygiene, visual text extraction accuracy, and tag correctness. 

The annotation and review guidelines enforced consistent tone, LaTeX formatting for math, timestamp fidelity, and a high level of accuracy across all tasks.

Key Results

  • Delivered more than 1,500 long-video tasks, each with segment-aligned captions, tags, and QA metadata
  • More than 500 videos contained audio, with structured transcripts and speaker labeling
  • More than 250 STEM videos captured causal reasoning, step-by-step instruction, and multimodal synthesis
  • Achieved 100% human-audited segmentation, with dual-pass QA for scene boundaries, caption accuracy, and visual tag coverage
  • Achieved consistent tagging coverage across motion, scene, visual text, audio, and camera movement

The Outcome

The resulting dataset gave researchers a fine-grained tool to benchmark video models on:

  • Long-form video coherence
  • Instructional fidelity in STEM settings
  • Audio-visual reasoning and transcript precision
  • Agentic evaluation with multi-turn, multimodal supervision

The client appreciated the annotation quality, LLM-assisted tooling, and guideline compliance.

Want to evaluate your model’s long-video comprehension?

Request a labeled task with context-level and fine-grained segmentation, visual and audio captioning, transcripts with speaker IDs, and STEM reasoning metadata.

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FAQ

What’s in a sample task?

Each sample task contains a fully segmented video with overview captions, clip-level tags, transcripts, and visual and audio annotations.

Do you support STEM and multi-speaker formats?

Yes. We delivered more than 250 STEM videos and many others with multi-speaker speech and overlapping dialogue.

Is this dataset suitable for LLM or agent evaluation?

Yes. It was purpose-built to test grounding, reasoning, and long-context alignment.

Are LaTeX and technical formatting supported?

Yes. Math captions use LaTeX and are formatted for scientific evaluation.

What’s the NDA process?

A standard mutual NDA. Turing provides the countersigned agreement within one business day.

How fast can I get a sample?

Within three business days after NDA execution.

How well does your model handle dense, real-world videos?

Request an annotated task featuring overlapping speakers, technical diagrams, and context-level segment structure.

Request Sample