How to normalize Lucene scores... (over all queries)

[Patrick Diviacco <pa...@gmail.com>]

I'm combining several scores for my queries performed with Lucene and other
software.

My issue is that I have lucene scores + other scores (not related to Lucene)
for each query result.

The other scores are all normalized between 1 and 0.

I need to normalize Lucene scores (over all queries) because If I don't
normalize Lucene scores in the same way I'm going to have unbalanced
results...

How can I make it ?
thanks

Re: How to normalize Lucene scores... (over all queries)

[Erick Erickson <er...@gmail.com>]

You can't. If by "normalize" you mean compare the scores
between two different queries, it's meaningless. The scores
from one query to another are not comparable.

If by "normalize" you mean make into a value between 0 and 1,
anywhere you have access to raw scores I believe you also have
access to the max score, and you can just divide.

But this smells like an XY problem. Can you back up and tell
us what the use case you're trying to solve is? Maybe there are
other possibilities.

Best
Erick

On Mon, Mar 21, 2011 at 12:09 PM, Patrick Diviacco
<pa...@gmail.com> wrote:
> I'm combining several scores for my queries performed with Lucene and other
> software.
>
> My issue is that I have lucene scores + other scores (not related to Lucene)
> for each query result.
>
> The other scores are all normalized between 1 and 0.
>
> I need to normalize Lucene scores (over all queries) because If I don't
> normalize Lucene scores in the same way I'm going to have unbalanced
> results...
>
> How can I make it ?
> thanks
>

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