Concretely, you will: Translate the requirements of video and multimodal models - video understanding, temporal and event localization, action recognition, long-form video, video-language models, video generation, cross-modal reasoning, and multimodal retrieval and grounding - into concrete data specifications: modalities, annotation schemas, sampling, and evaluation criteria. Video spans two model families judged in completely different ways: models that understand video - answering questions, localizing events, grounding language in time - where the question is whether the answer is correct; and models that generate it, where fidelity, temporal coherence, and physical plausibility matter and no automatic metric is settled.