3 ms·
They managed to test and train on different periods of time. February 28, 2008 to November 28, 2008 is chosen as the longest possible training period w
by b0b0b0b 16y ago
They managed to test and train on different periods of time.
February 28, 2008 to November 28, 2008 is
chosen as the longest possible training period while
Dec 1 to Dec 19, 2008 was chosen as the test period
That said, their split exhibits enormous bias:
Dec 1 to Dec 19, 2008 was chosen as the test period
because it was characterized by stabilization of DJIA
values after considerable volatility in previous months
and the absence of any unusual or significant socio
cultural events
I don't understand why they would think this is okay.
- Robin_Message 16y agoWhoops, missed that. Well then, in the absence of unpredictable events, twitter could predict the stock market, but it can't anymore since the market will now factor this new knowledge in (assuming perfect markets of course.)
- enjo 16y agoPendantic response: Perfectly efficient markets. Which, as a theory, has been under rather serious siege for the better part of the last decade. You can certainly make a behavioral argument that would reach more or less the same conclusion, however.
- enjo 16y agoPendantic response: Perfectly efficient markets. Which, as a theory, has been under rather serious siege for the better part of the last decade. You can certainly make a behavioral argument that would reach more or less the same conclusion, however.
- pessimizer 16y agoI can see exactly why they would think it was okay. What they were trying to do was to figure out whether twitter moods could predict the unpredictable random movements of the market, rather than the outside edges of the bell curve when anyone could have predicted what would happen, and where the market moves might even be seen as a cause of the twitter moods rather than a result, or a co-result of some other process. Basically, it's the hardest place to test the correlation. Since they got great results, it'll be interesting to see them extend the analysis and see if any interesting dynamics show up.