Comments on: Did you mean… ? In php

By: alex

alex — Tue, 03 Jun 2008 19:23:44 +0000

Well that might be indeed a better solution, although I would like to test both with several different terms and cases and note down results and processing time to ensure what is the best way to approach this.
Your might be better, although for normal sites that don’t really need that good search engines I guess it would be easier for them to run the MySQL query using SOUNDEX() and the soundex key of the input word…

Thanks for that

By: ali asaria

ali asaria — Tue, 03 Jun 2008 02:43:12 +0000

a better solution, in our work, was to make a custom dictionary. see:
http://www.indirecthit.com/2007/08/24/google-did-you-mean-on-search-pages-using-php-4/

By: alex

alex — Mon, 02 Jun 2008 16:25:53 +0000

@Sergei:
Nice!
Although I’m not sure that they are using the best approach, since it is language-dependent, whereas I doubt Google actually performs a real spell check.
I am guessing it searches for similar words using one of the functions (Or altered versions of them) to get slighly variated words, and then performs searches also with them…

But you never know

By: Sergei

Sergei — Mon, 02 Jun 2008 14:23:09 +0000

This is an example in Python, but very useful. http://norvig.com/spell-correct.html

By: Jasper

Jasper — Sat, 31 May 2008 20:59:32 +0000

I had no idea there were such functions in PHP. Cheers for the article, I’ll be using this in the near future!

By: roScripts - Webmaster resources and websites

roScripts - Webmaster resources and websites — Sat, 31 May 2008 14:15:06 +0000

Did you mean… ? In php | Urbanos Blog…

In a new website I am developing for a client I had to add the usual Did you mean in the search results for her Si I started thinking for the easiest…

By: Did you mean… ? In php | Programmers Blog

Did you mean… ? In php | Programmers Blog — Sat, 31 May 2008 12:17:54 +0000

[...] http://urbanoalvarez.es/blog/2008/05/30/did-you-mean-in-php/ [...]

By: alex

alex — Fri, 30 May 2008 19:11:20 +0000

Nice, thanks for the advice, I didn’t know MySQL had that function. Then yes, use it directly, unless you want to use the metaphone function, which apparently isn’t included yet in MySQL (There is a request to have it included in following versions already)

Thanks for that, I’ll update the post now to reflect that,
Alex

By: alex

alex — Fri, 30 May 2008 19:07:44 +0000

Well of course I wouldn’t use Levenshtein for large volumes of data without some sort of index or cache as you say…
In case you want to do it with large dictionaries I would probably create a column with the soundex or metaphone keys and then search both for the string as-is and then for the soundex key.
Using it that way you could even display the percentage of closeness…

Probably i would say that Levenshtein is great for small sized databases, or array search. But for large scale search the soundex is just perfect.

Thanks for the correction,
Alex

By: Tristan

Tristan — Fri, 30 May 2008 16:11:18 +0000

how big is the dictionary that you use? Levenshtein is O(mxn). you cant get much better for this sort of operation, but assuming that the input is 7 chars, and target string is an average length of 6, then we have 42 operations to determine its length. assuming a rather puny dictionary size of a 1000 words every page view/search will require 42000 operations? that sort of math doesnt scale.

you may want to look at storing the results of each search in a dbms as a sort of long term cache.

By: Anna Kolesnik

Anna Kolesnik — Fri, 30 May 2008 15:37:52 +0000

cool and sweet tip .. I like you syntax highlighting plugin in the Wordpres abc :))

By: ryan

ryan — Fri, 30 May 2008 15:36:49 +0000

Wow, didn’t even know these functions existed. Thanks for the lowdown.

By: Paul Decowski

Paul Decowski — Fri, 30 May 2008 15:34:32 +0000

“(…) already created a column in the mysql tables with the soundex key (…)”
Or use SOUNDEX() function provided by MySQL.