  We introduce EgoSchema, a very long-form video question-answering dataset,
and benchmark to evaluate long video understanding capabilities of modern
vision and language systems. Derived from Ego4D, EgoSchema consists of over
5000 human curated multiple choice question answer pairs, spanning over 250
hours of real video data, covering a very broad range of natural human activity
and behavior. For each question, EgoSchema requires the correct answer to be
selected between five given options based on a three-minute-long video clip.
While some prior works have proposed video datasets with long clip lengths, we
posit that merely the length of the video clip does not truly capture the
temporal difficulty of the video task that is being considered. To remedy this,
we introduce temporal certificate sets, a general notion for capturing the
intrinsic temporal understanding length associated with a broad range of video
understanding tasks & datasets. Based on this metric, we find EgoSchema to have
intrinsic temporal lengths over 5.7x longer than the second closest dataset and
10x to 100x longer than any other video understanding dataset. Further, our
evaluation of several current state-of-the-art video and language models shows
them to be severely lacking in long-term video understanding capabilities. Even
models with several billions of parameters achieve QA accuracy less than 33%
(random is 20%) on the EgoSchema multi-choice question answering task, while
humans achieve about 76% accuracy. We posit that \name{}{}, with its long
intrinsic temporal structures and diverse complexity, would serve as a valuable
evaluation probe for developing effective long-term video understanding systems
in the future. Data and Zero-shot model evaluation code are open-sourced for
both public and commercial use under the Ego4D license at
http://egoschema.github.io
