On Oct 21, 2005, at 7:19 PM, James Holderness wrote:
What's the difference between a search feed and a non-incremental
feed? Aren't search feeds one facet of non-incremental feeds?
Not necessarily, no. A search feed could quite easily be
implemented as an incremental feed. This is the most sensible
approach since it would allow the feed to be viewed in all existing
aggregators without requiring a special knowledge of non-
incremental feeds.
If your goal is to work as well as possible with today's client
software, then bending your data to fit their model is the most
sensible approach, but that's not always the goal.
The initial feed document consists of all known results at the time
the search is initiated. As new results are discovered over time,
the feed can be updated by adding new entries to the top of the
feed in much the same way that new entries would be added to the
top of a blogging feed. In fact, if you do a search with something
like feedster, this is exactly the sort of feed you will get back.
If creation time is relevant to the data being searched, then this
makes sense. But what if I want to subscribe to the top 10 Google
results for some keywords I'm trying to optimize my site for
(ignoring the fact that Google doesn't return search results in any
feed format right now)? Or what about alternative sort orders which
are available on sites like Feedster, Google News, etc.? (You can
sort by relevance rather than date--the date still has some weight,
but the results aren't strictly in date order). How about Amazon.com
affiliates who want to use an RSS parser to display affiliates links
to "best sellers" search results? There are a lot of search use
cases that don't fit the incremental model.
All that said, search results are often a bit different than "top 10"
lists and the like. With search results, you often don't want to
view the contents of the feed in order all at once--the first time
you do, but after that, you may just want to see new things as they
make it up into the top positions. Today's clients can handle that
just fine, unless you want to monitor more than just the first page
of results.
