Experiments with the Brandwatch API. Can twitter volume/sentiment predict the share of the vote in the 2014 Local/European Elections?
 

Polling Day (Thu 22nd May 2014) Midnight - 10:19pm

 ukiptorylibdemlabourgreen
total mentions22.6%20.4%16.6%19.9%20.4%
positive sentiment18.4%14.5%16.9%21.6%28.5%
negative sentiment33.3%23.5%13.7%19.2%10.3%
source - brandwatch API
ukip - pos:362 neg:1044 neu:9860 tot:11266
tory - pos:286 neg:736 neu:9172 tot:10194
libdem - pos:333 neg:431 neu:7500 tot:8264
labour - pos:426 neg:602 neu:8907 tot:9935
green - pos:561 neg:324 neu:9307 tot:10192
 

Previous 7 Days

 ukiptorylibdemlabourgreen
total mentions28.3%22.8%8.9%29.7%10.3%
positive sentiment32.8%16.9%6.9%30.4%13.0%
negative sentiment33.5%26.3%7.1%29.4%3.6%
source - brandwatch API
ukip - pos:2726 neg:5773 neu:52510 tot:61009
tory - pos:1409 neg:4524 neu:43146 tot:49079
libdem - pos:574 neg:1227 neu:17275 tot:19076
labour - pos:2530 neg:5063 neu:56404 tot:63997
green - pos:1080 neg:621 neu:20571 tot:22272
 

Aggregated Prediction

 ukiptorylibdemlabourgreen
7day pos + tot / 230.5%19.9%7.9%30.1%11.7%
 
 

Polls

  ukiptorylibdemlabourgreen
Survation/Mirror 20/05/14 32%23%9%27%4%
YouGov/Sun 20/05/14 27%23%10%27%8%
YouGov/Sun 19/05/14 24%21%10%28%12%
ComRes/ITV 18/05/14 33%20%7%27%6%
YouGov/Sunday Times 16/05/14 26%23%9%27%9%
ICM/Sunday Telegraph 15/05/14 25%26%7%29%6%
ComRes/Indy on Sunday 15/05/1435%20%6%24%7%
YouGov/Sun 14/05/14 25%22%10%28%10%
Opinium 12/05/14 30%22%7%28%5%
ICM/Guardian 11/05/14 26%27%7%24%10%
sources
 

 
Update Tues 27th May, with final results...
 

EU Election 2014 share of the vote

 ukiptorylibdemlabourgreen
  27.5% 23.9% 6.6% 25.4% 6.9%
  Other parties (SNP, Sinn Fein, Plaid Cymru & 21 others): 9.7%
source: http://en.wikipedia.org/wiki/European_Parliament_election,_2014_(United_Kingdom)
 

Prediction (from above)

 ukiptorylibdemlabourgreen
  30.5% 19.9% 7.9% 30.1% 11.7%
  +3.0% -4.0% +1.3% +4.7% +4.8%
 
Note: the total difference adds up to 9.8% which is, of course, the figure unaccounted for in this five-party split - those who voted for other parties. So...
 

Prediction (adjusted to account for 9.7% "other")

 ukiptorylibdemlabourgreen
val / 109.7 * 100 27.8% 18.1% 7.2% 27.4% 10.7%
  +0.3% -5.8% +0.6% +2.0% +3.8%
 
So, apart from the tory stalewarts (who we might expect to be less represented on a modern platform like Twitter), and the Greens (whose social media activity may have been a compensation for their under-representation in other media) ... my conclusion - NOT BAD!
 
Further analysis and an explanation of the fudges behind these figures: COMING SOON...