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Re:Ask HN: Review ContextSense - deduces context and sentime... by yannis on Thursday September 10, 2009 @12:53PM (#815618)
http://en.wikipedia.org/wiki/The_Holocaust

Slightly Negative (0.33)

Extract From the same link (text only as shown below) Highly Positive 0.81!

>The usual German term for the extermination of the Jews during the Nazi period was the euphemistic phrase Endlösung der Judenfrage (the "Final Solution of the Jewish Question"). In both English and German, "Final Solution" is widely used as an alternative to "Holocaust".[16] For a time after World War II, German historians also used the term Völkermord ("genocide"), or in full, der Völkermord an den Juden ("the genocide of the Jewish people"), while the prevalent term in Germany today is either Holocaust or increasingly Shoah.

NLP is H A R D, I know and defining a range value for sentiment even harder.

Re:Ask HN: Review ContextSense - deduces context and sentime... by paraschopra on Thursday September 10, 2009 @12:57PM (#815630)
Yup, I agree -- though more data provides more oppurtunities to make a better guess.
Re:Ask HN: Review ContextSense - deduces context and sentime... by paraschopra on Thursday September 10, 2009 @11:44AM (#815459)
Hey guys, my startup (Wingify) has exposed an API for determining sentiment and context from any URL or piece of text. I'll be glad if you could review it.

ContextSense was made to demonstrate our contextual targeting capabilities -- and sentiment aspect was added to avoid traditional blunders of displaying ads on pages/news on catastrophies. Best to try ContextSense with text heavy URLs. Also try it with news items (both positive and negative).

I will be happy to provide API access in case any of you is interested in trying it out.

Re:Ask HN: Review ContextSense - deduces context and sentime... by elcron on Thursday September 10, 2009 @05:23PM (#816230)
Cool! I tried something like this, it classified blog posts into 100 different moods... it had ~8% accuracy (It also classified as positive or negative, but I don't remember the accuracy, I'll have to dig it up at some point...). Good luck with it.
Re:Ask HN: Review ContextSense - deduces context and sentime... by paraschopra on Friday September 11, 2009 @12:16AM (#816835)
Do you remember what was it? I will be really curious to have a look. Thanks.
Re:Ask HN: Review ContextSense - deduces context and sentime... by elcron on Friday September 11, 2009 @02:56PM (#817871)
It was accurate around 56% of the time classifying as positive, negative, or neutral. I used a naive Bayesian classifier and guessed the highest rather than showing the percent positive.
Re:Ask HN: Review ContextSense - deduces context and sentime... by byoung2 on Thursday September 10, 2009 @12:29PM (#815558)
I searched for http://school.discoveryeducation.com/schooladventures/slaver...

Few human practices have provoked such deep and widespread outrage as the practice of one human being enslaving another. So why has slavery survived for thousands of years? How did it become so important to civilization? Explore the ways that slavery has been woven into the fabric of societies in America and around the world.

Sentiment: Highly Positive (0.77)

Seems off in cases where the tone of the text is neutral but the subject matter is negative.

Re:Ask HN: Review ContextSense - deduces context and sentime... by rwolf on Thursday September 10, 2009 @01:55PM (#815773)
The comments so far refer to the "sentiment deducer" aspect of the service. They've brought up some examples of how it's not working right now, but they missed an important question: what in the world is "positive sentiment" abstracted from context, and why would I want to know if a site had it?

An issue we haven't brought up is tags. Current tags for HN: "ago, points, comments, com, hours, hour, hacker, discuss, minutes, tornado." I see some good ones, but it's quite noisy (and it seems to have grabbed the tornado story as a main topic--scraping the title?). This feature seems most useful to me, and most easy to improve.

Re:Ask HN: Review ContextSense - deduces context and sentime... by paraschopra on Friday September 11, 2009 @12:15AM (#816834)
No, not just a title but the whole website. The algo currently works on TF-IDF of the tags, and HN is full of points, ago, hours, etc. repeated all over it. This increases the TF. We would be putting an upper limit on it though.
Re:Ask HN: Review ContextSense - deduces context and sentime... by rwolf on Friday September 11, 2009 @12:59AM (#816885)
I didn't mean the title tag--I meant the first story title (the SEO kids talk about google fixating on the first h1 tag of a site, I though it might be a similar idea). I have no idea what this upper limit change would do, but good luck.
Re:Ask HN: Review ContextSense - deduces context and sentime... by frig on Thursday September 10, 2009 @01:23PM (#815692)
I put this in:

http://en.wikipedia.org/wiki/C*-algebra

The results are better than I would've guessed, but not really so great (this article is pretty degenerate I think, versus more "human-interest" type stories).

One thing I'm curious out: the list of topics is here:

People (7.88) Algebra (4.47) Research Groups (3.41) Software (2.42) Math (2.03) Functional Analysis (1.53) Journals (1.01) Science (0.71) Publications (0.64) Logic and Foundations (0.6)

...does looking at the content give you any sense for why "People" comes in first?

Re:Ask HN: Review ContextSense - deduces context and sentime... by paraschopra on Thursday September 10, 2009 @01:33PM (#815720)
Yes,the false positive rate is a not the least and we are working on decreasing it!
Re:Ask HN: Review ContextSense - deduces context and sentime... by frig on Thursday September 10, 2009 @01:40PM (#815740)
I guess what I'm asking is: is "People" just a default answer?
Re:Ask HN: Review ContextSense - deduces context and sentime... by paraschopra on Friday September 11, 2009 @12:18AM (#816840)
No, People is not a default answer. It is due to underlying taxonomy data. Working on refining the database.
Re:Ask HN: Review ContextSense - deduces context and sentime... by erikwiffin on Thursday September 10, 2009 @06:19PM (#816334)
Reading the other comments, it looks like your biggest problems are false positives. It might not be a bad idea to put together some kind of feedback mechanism - in the event that I disagree with the sentiment/tags/categories that I could provide better ones and you could eventually use that data to refine your algorithm.

That being said, this looks really cool and full of potential, now I just need a reason to be auto-generating that kind of meta data.

Re:Ask HN: Review ContextSense - deduces context and sentime... by onewland on Thursday September 10, 2009 @02:44PM (#815880)
I think positive/negative is too shallow. I actually do enjoy this, but I think you need to rate sentiments on other vectors, so if I rate http://teddziuba.com/ I get something like:

Anger: 25 Smugness: 50 Vulgarity: 15 Boredom: 5

etc.

I'm not even sure that's a good example or if it's clear, I just think positive/negative is an oversimplification of the sentiment of most sites.

Re:Ask HN: Review ContextSense - deduces context and sentime... by wlievens on Friday September 11, 2009 @05:59AM (#817091)
Whatever you do, Ted Dzubia will break any scale.
Re:Ask HN: Review ContextSense - deduces context and sentime... by quizbiz on Thursday September 10, 2009 @02:01PM (#815792)
Have it recommend changes. Tell us what we can do to improve.
Re:Ask HN: Review ContextSense - deduces context and sentime... by mishmax on Thursday September 10, 2009 @12:34PM (#815570)
Would be nice if it didn't need http in front of a url.
Re:Ask HN: Review ContextSense - deduces context and sentime... by DanielStraight on Thursday September 10, 2009 @11:52AM (#815472)
Can't get it to work. Won't load.
Re:Ask HN: Review ContextSense - deduces context and sentime... by paraschopra on Thursday September 10, 2009 @11:53AM (#815475)
Which browser? Platform? And which URL?
Re:Ask HN: Review ContextSense - deduces context and sentime... by DanielStraight on Thursday September 10, 2009 @12:00PM (#815494)
Firefox 3.5.3 on WinXP 64 with the URL that comes up when you load the site. The status spinners just keep spinning forever.
Re:Ask HN: Review ContextSense - deduces context and sentime... by paraschopra on Thursday September 10, 2009 @12:05PM (#815500)
Thanks for the info. Strangely, with exactly same configuration (except WinXP 32 -- which shouldn't make any difference), this is working for me.
Re:Ask HN: Review ContextSense - deduces context and sentime... by thorax on Thursday September 10, 2009 @12:28PM (#815557)
What Firefox extensions? Works great here on XP 64.
Re:Ask HN: Review ContextSense - deduces context and sentime... by DanielStraight on Thursday September 10, 2009 @12:53PM (#815621)
None that should interfere... Firebug, Site Launcher, Colorzilla.

I typically have cookies disable, but I turned them on and it made no difference.