Giles Palmer - Social Media '09 (a mashup* event)

Sentiment analysis

Who am I?

personal tags:

giles palmerfounder and ceo of brandwatch.net – buzz monitoring to the starstaller than your average joe

please sponsor my tash at:www.movember.com

http://www.movember.com/

3www.brandwatch.net |

Sentiment – so why’s that important then?

Politicians are obsessed

with it


Companies like it because it can help predict….


Sales

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Some sentiment stats

www.brandwatch.net |


The sentiment of the web

Sample size 400,000 web pages about 1,000 different things

28%

14%

58%

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People don’t agree with each other all the time


(Arsenal 2 : 1 Man Utd)

In our tests, people agree on sentiment 85% of the time


Top ‘Brands’ in October – English speaking web

Volume ‘000s Sentiment * Volume Sentiment



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How do you measure the sentiment of millions of webpages?


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Crowdsource ?


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Downsides to crowdsourcing


Slow (compared to machines)

Inconsistent

Expensive

e.g. Article takes 2 minutes so 30 articles per hour

You need native speakers, so £6/hr

=> Article costs £0.2 to read

10,000 articles * £0.2 = £2,000

(Twitter is cheaper)

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Machines ?


Q: Can we RELIABLY get a machine to do sentiment analysis ?

A: Kind of

Q: How ?

A: You teach it to mimic your own behaviour using a branch of Artificial Intelligence called Machine Learning

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Teaching machines


1. Decide what text to feed in

2. Train them (lots)

3. Audit and improve (lots)

It’s not quick


BSkyB has struck a deal with Apple to launch its mobile TV service providing live access to sport including Premier League football matches on the iPhone.

From today the service, Sky Mobile TV, will be made available to iPhone and iPod Touch owners via a new application at the Apple App Store.

The application allows iPhone owners to stream live TV – via a Wi-Fi connection – from a selection of channels including the Sky Sports portfolio, Sky Sports News, ESPN, At The Races and Sky News. The sports and news package will cost phone owners £6 a month.

Sky's mobile TV service allows iPhone owners to access live televised matches from the Barclays Premier League, Scottish Premier League and Football League, as well as sport such as European Tour golf, Premiership rugby and international and domestic cricket.

The application is free to download and is being made available to all iPhone owners regardless of which mobile network they are signed to.

Sky Mobile TV is already available, for £5 a month, on the 3G networks of Vodafone, Orange and T-Mobile.

In the past year BSkyB has launched a number of applications in the Apple App Store, for football, cricket and news updates, and claims more than 2m downloads so far.

"In less than a year we've already seen millions of downloads of Sky's various iPhone apps," said David Gibbs, the general manager for mobile at Sky. "Now, by launching our new Sky Mobile TV app, we are able to combine the demand for great live TV on the move with the quality of experience offered through the iPhone and iTouch."

As part of the launch of the service mobile network operator O2 is giving its iPhone customer base three months' free subscription to Sky Mobile TV.


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How to train machines


1. A trained native speaker reads something and tags it

2. Feed that data into the program

3. Repeat many times

4. The program use this information to build up statistical maps

5. Then you feed an untagged snippet in and the machine gives it the tag that’s statistically closest to its training

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Different language


•Results are only as good as the training (Royal Mail)

•Type of language used has big effect eg Insurance news vs online gaming forums

•Foreign languages are done in the same way

Stats

•Training to date 650,000 mentions in 60 industries from merchant banking to military

•Accuracy ranges from 94% for Swedish videogames to 50% for Portuguese telecom

Good target is 75% which is achievable

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The best approach


For small volumes – crowdsource

For large volumes – use machines, but also look at the most important mentions manually

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Recap


•Machine-based sentiment IS possible

•It’s not as good as people (who are native speakers)

•The text you feed into the program is critical

•Machines need a lot of training

•A combined approach is probably best for most

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Free giveaway!!


Brandwatch 4.0 is out at the end of November

50 Free Beta testing accounts

www.brandwatch.net/4.0

[email protected]

http://www.brandwatch.net/4.0

Business

Giles Palmer - Social Media '09 (a mashup* event)