I always enjoy the PEW research on various topics. The PEW research Center looked at various events over the course of a year to determine if twitter trends with the overall public opinion of the US or does not. In other words when a statistically valid sample is taken from individuals in the United States and the gauge opinions on various topics how does Twitter compare. I think they were trying to determine if they could use the discussions on twitter as a barometer of public opinion. It appears from this research the answer is no.
Go here to see the entire study. It is a very good read and well done. The result was essentially that when comparing a statistically valid sample across United States to twitter the results were not the same. Many people would probably already have guessed that twitter and a valid sample determining public opinion would be different. When you take a poll they attempt to take an even sample in a statistically valid sample.
When you look at the reactions on twitter you are not taking a statistically valid sample you are just looking at all of the people on twitter. If the demographic of the individuals on twitter happen to match what a cross-section of America would look like when a poll is conducted than it would’ve worked fine. However that is not the case. I do not know exactly what or how the demographic skews on twitter but it definitely skews. Most importantly it is only 13% or so of the United States according to the research. That in and of itself does not mean it is invalid if of course the demographics matched up appropriately.
I think it is good for news outlets and others to understand that they cannot rely on twitter data to determine what the overall public opinion is. Another interesting thing they found is that regardless of the issue people or more likely to talk negatively about something and positively. Most of the tweets in some of their scenarios were negative tweets. I guess the old adage that people prefer to complain holds true even for those that use twitter.
Take a look at the pew research on this particular versus public opinion and take a look at the rest of their information as it is always informative and on many various topics.