Great interface, however: I don't find myself trusting the results when it populates differently depending on how quickly I type a word. Typing "chemistry" at different rates gives different results, including some results that aren't related to chemistry (such as banking). By the way I type generally between 70-140+wpm depending on the word.

Thanks for the feedback! I'm "threading" the search to not block the browser, maybe typing fast can interfere with correctly restarting the search. I will investigate!

Cool in concept, but your search algorithm leaves something to be desired.

Your app reminded me I wanted to watch Khan's videos on IPOs, so I type in: IPO ... about half way down the list of ~50 results are the videos I wanted to watch (An IPO, More on IPOs).. I actually had to do a Ctrl-F to find them in the result list.

bjacobso, what search utility are you using on the backend? -- Are you using YouTube search? - Or are you building your own index using Sphinx,Solr/Lucene,etc. - Or some combination of?

It is actually all being done client side. I download a video list in json and create a client side document store. I figured searching 1500 items wasn't worth doing a server roundtrip. I then just search youtube for the title of the video they choose.

I use quicksilver.js to match items. I probably need to increase the score threshold to ensure more accurate results.

I was just thinking today that they (Khan Academy) should add an instant search instead of the wall of links they have currently. For a user such as one of us, the wall of links is ideal for a CTRL-F find to quickly highlight lessons on, say, vectors, but for non-technical users, this solution may not come to mind.

Thank you very much. I have been looking for a better search for KA and instant results are a plus.

Nicely done! It would be nice if you would allow the user to fullscreen the videos. I think adding "allowFullScreen: true" to your params object for your js embed would add this functionality.

Can I get Instant Instant? Where I want to search for a general topic generally and by typing in something, the instant search instant returns the best instant search engine?

Very meta. Maybe I will tackle that for my next project.

Genius. Yep, I said it. But the initial video showed confused me when I did a new search and the video stayed the same. Shouldn't the most relevant video load instantly?

I would agree, it is probably confusing initially. It would make sense to follow the heuristics of other instant search sites. However, when I experimented with auto updating the video it just didn't "feel" right. For some reason I think a user selection model is a better UX in this case.

I think this is a great opportunity to do some A/B experimenting. You could start a new thread.

Minor bug: "searching" for startup yields two of the same video, instead of the two parts of Khan's presentation on founder equity.

Thanks for the feedback!

Currently, it only "searches" the title of the video and the playlist name. If I had transcripts of the videos (they may exist somewhere?) then it could be WAY more relevant.

Some videos show up twice because the same video exists in two different playlists. I'll fix it.

Try "linear algebra," it doesn't really yield good results.

Great idea. May want to turn off browser's own 'autocomplete' as its popup results obscure the top of those in your page.

Excellent suggestion, done. Thanks!

I certainly don't want to hurt the credibility of the Khan Academy. I just thought this would be a fun project.. wouldn't mashups actually be evidence of interest and lend more credibility?

I share your sentiment but I don't think a few links that do well on HN seriously represent the "industry."

HN is more a talking shop for founders and hackers than a public showcase for the Internet's latest and greatest apps. A lot of what goes on here does migrate to the public sphere, but there's no reason to curb the injokes or "fads" to maintain an image on an industry-focused site.

So... Politicians are going to legislate unfavorably on the technology industry because, for some fun in their spare time, a few people adapted the concept of instant search to various different websites?

It's not like he's asking for investors for this, its just a neat, and useful, app.

I would appreciate it if you explained this further.

I think he's referring to all the "Instant" copycats.