Capturing complex workflow provenance

[cneud]

@acpopat wrote:

Some processing histories may not be simple sequential pipelines and may require a more general graph structure. As mentioned in today's board call, some OCR post-correction schemes provide examples of such processing:

• merging results from multiple OCR engines
• post-correction using multiple information sources
• coalescing information from multiple page images and their OCR results

If it is desired that the results of such processing be represented in ALTO, then a more general provenance scheme capable of representing graph-structured dependencies might be required, such as that referred to by Clemens in his Aug 2 comment.