Full Text Search - how do I retrieve the score of a document?

[jon]

Hi,

For a given ScoredDocument, how do I get its "relevance score"? The
official example app doesn't demonstrate scoring. This documentation
implies that QueryOptions.Builder has a setScorer() method but it
doesn't exist. https://developers.google.com/appengine/docs/java/javadoc/com/google/appengine/api/search/Query

I can see that ScoredDocument has a getSortScores() method that
returns a List. I'm not quite sure what this is. I will try it out and
see what it does. In the meantime if someone has some info on scoring
I'll be grateful if you can shed some light.

Thanks,
Jon

[Phil McDonnell]

Does anyone have an example of how they implemented scoring using the Text Search API? The documentation exposes ANDs and ORs in the search query with a sort ASC/DESC type of sorting on a field, but that sorting is not super helpful for most search applications. I imagine most any real use case here needs scoring implemented. Any examples out there?

Thanks,

Phil

--
You received this message because you are subscribed to the Google Groups "Google App Engine" group.
To post to this group, send email to google-a...@googlegroups.com.
To unsubscribe from this group, send email to google-appengi...@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.

[jon]

I'm afraid my original question is still unanswered. I still don't know how to grab relevance score. I have a feeling that there's no Googler that's been assigned to look after FTS questions in this group :-(

[Amy Unruh]

hi,

The match scorer does relevance scoring based on term frequency.  You can configure it as a sort option:

QueryOptions.newBuilder()

    .setSortOptions(SortOptions.newBuilder()

        .setMatchScorer(MatchScorer.newBuilder()))

    ...

    .build();

then access the scores in the query results:

for (ScoredDocument scoredDoc : results) {
    out.println("Score: " + scoredDoc.getSortScores().get(0));
}

If you access _score in a sort expression, e.g (suppose you have a field called 'price'):

SortExpression sortExpr = SortExpression.newBuilder()

    .setExpression("price + _score")

    .setDefaultValueNumeric(0.0)

    .build();

then your SortOptions object should include a scorer. e.g.:

SortOptions.newBuilder()

    .setMatchScorer(MatchScorer.newBuilder())

    .addSortExpression(sortExpr)

    ...

    .build();

You might find the examples in this set of slides useful: http://fts-webinar.appspot.com/ .  Both python and java examples are included.

On 12 September 2012 12:42, jon <jonni...@gmail.com> wrote:

I'm afraid my original question is still unanswered. I still don't know how to grab relevance score. I have a feeling that there's no Googler that's been assigned to look after FTS questions in this group :-(

--

You received this message because you are subscribed to the Google Groups "Google App Engine" group.

To view this discussion on the web visit https://groups.google.com/d/msg/google-appengine/-/bn2-B7VbApEJ.