GSoC-2017 Introduction and Project Discussion

[Shivang Bansal]

> Hi Shivang! Welcome to Xapian :)

Hello James. Thank you :)

> It's worth pointing out that xapian-delve is not a shared library.
Perhaps you mean you had difficulties with shared libraries while building
or >running it?

Yeah that's exactly what I meant, libxapian-1.5.so to be specifically.

>The fact that you're using xapian-delve-1.5 tells me that you're using the
development work from git, which is not the recommended >approach in the
getting started guide, but is absolutely the right way when working on
Xapian's codebase. (You probably need to look at the >Xapian developer
guide to ensure you're set up properly with the development codebase:
https://xapian-developer->guide.readthedocs.io/en/latest/)

Thanks for mentioning, I've got your point.

> You'll need to propose quite a lot of detail on how you're going to
implement this using the Xapian backend database and weighting >system. I
suspect you'll have to extend it a fair amount to support TW-IDF, because
we have no graph support at present. I haven't read the >paper though, so
it's possible you can do this using some preprocessing in some way.

I will surely try to propose a completely detailed plan on how
graph-of-words model could be implemented in Xapian. The fact that Xapian
does not support graph at present could make things a bit difficult. But, I
strongly believe that it would be worthful as this model will judge the
terms according to their relationship order in the documents which would
enhance the effectiveness of search results (please let me know if you
think otherwise).

> It's also worth noting that we've sometimes seen quite different
evaluation results to the academic research in the past. There's a module
>that implements some evaluation metrics (
https://github.com/samuelharden/xapian-evaluation) which can be used to
gauge how a new ?>weighting scheme compares to the others we have, designed
to run with TREC data.

This module will surely play a key role in the evaluation. I will look into
it as well.

> Again, you'll need to propose how to fit TF-ATO into Xapian's database
and weighting framework. Can the document centroid approach be >done as a
processing step during indexing? (Again, I haven't had time to read the
paper yet.)

I didn't get exactly, what you mean by 'during indexing'. What I can think
of is, after we had indexed all the terms and assigned weights to each
index term. If that's what you mean then yes, document centroid approach
can be computed at that time only from the documents vectors of term
weights. Its basic aim is to reduce the size of documents in the dataset by
the discriminative approach which is nothing, but to remove the terms
having weight lesser than documents centroid. According to the paper, this
approach gives an average reduction in size of 2.3% from the actual dataset
size.
I will come up with a detailed proposal for this scheme as well.

Thank You for your time.

Regards,
Shivang Bansal
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