They say:
"ARC-AGI tasks are a series of three to five input and output tasks followed by a final task with only the input listed. Each task tests the utilization of a specific learned skill based on a minimal number of cognitive priors.
Tasks are represented as JSON lists of integers. These JSON objects can also be represented visually as a grid of colors using an ARC-AGI task viewer.
A successful submission is a pixel-perfect description (color and position) of the final task's output."
As far as I can tell, they are asking to reproduce exactly the final task's output.
What they mean by "specific learned skill" is that each task illustrates the use of certain "core knowledge priors" that François Chollet has claimed are necessary to solve said tasks. You can find this claim in Chollet's white paper that introduced ARC, linked below:
"Core knowledge priors" are a concept from psychology and cognitive science as far as I can tell.
To be clear, other than Chollet's claim that the "core knowledge priors" are necessary to solve ARC tasks, as far as I can tell, there is no other reason to assume so and every single system that has posted any above-0% results so far does not make any attempt to use that concept, so at the very least we can know that the tasks solved so far do not need any core knowledge priors to be solved.
But, just to be perfectly clear: when results are posted, they are measured by simple comparison of the target output grids with the output grids generated by a system. Not by comparing the method used to solve a task.
Also, if I may be critical: you can find this information all over the place online. It takes a bit of reading I suppose, but it's public information.
They say: "ARC-AGI tasks are a series of three to five input and output tasks followed by a final task with only the input listed. Each task tests the utilization of a specific learned skill based on a minimal number of cognitive priors.
Tasks are represented as JSON lists of integers. These JSON objects can also be represented visually as a grid of colors using an ARC-AGI task viewer.
A successful submission is a pixel-perfect description (color and position) of the final task's output."
As far as I can tell, they are asking to reproduce exactly the final task's output.