I have a scenario where a user uploads documents to a system.

the user selects from their hard drive a document. This is added to a screen where the user can add meta data to the file (first upload stage)

The user then clicks upload where the original file and its metadata are added to the system (the second upload stage)

The user may be uploading many files at once

the system must prompt if there are duplicate files at the first upload stage and highlights the duplicates so the user can either a)remove from system b)proceed with second upload stage and overwrite *any existing files

my question: are not duplicate checks done at the final upload stage, not the first? So why doesn't the system just say at final stage "over-write existing versions?" (or better wording)

should the user be prompted at all?

I have a scenario where a user uploads documents to a system.

the user selects from their hard drive a document. This is added to a screen where the user can add meta data to the file (first upload stage)

The user then clicks upload where the original file and its metadata are added to the system (the second upload stage)

The user may be uploading many files at once

the system must prompt if there are duplicate files at the first upload stage and highlights the duplicates so the user can either a)remove from system b)proceed with second upload stage and overwrite *any existing files

my question: when is the best time to prompt for validation? As early as possible? Should the user be prompted at all and do you think the system should just overwrite the existing files with caveat dialogue along the lines of "any existing files will be replaced"