SOURCE: Social Weather Stations 2nd Quarter 2009 Press Release
This Chart summarizes over two years of SWS polling on the following question:
Under the present Constitution, the term of Pres. Arroyo is up to 2010 only, and there will be an election for a new President in May 2010. Who do you think are good leaders who should succeed Pres. Arroyo as President? You may give up to three names.Various headlines are derived (sold?) from the quarterly public opinion polling data collected by SWS, in this case, from asking 1500 respondents the above question and tallying up how often various personalities are mentioned. But the claimed Margin of Error of plus or minus 2.5 percent is SPURIOUS, as one can easily verify that the reported percentages do not add up to 100%! Since there is no fixed menu of candidates given in the question, and the respondents were free to name up to three choices, this form of statistical survey cannot be analyzed and its accuracy ascertained using the methods that are applicable to surveys where there should only strictly speaking be two choices.
The more realistic measure of how accurate this series of polls is likely to be can be better seen in the numbers of one particular "CANDIDATE" that is never mentioned in the SWS spin of its own data: namely that of NONE or DON'T KNOW, which an inspection of the above chart will show actually competes with the leaders of the survey, and in fact, apparently topped the First Quarter SWS survey. But this fact never made it to the headlines.
Indeed, I would submit that the REAL STATISTICAL ERROR in the SWS survey is at least half of the NONE or DON'T KNOW percentage, that is, closer to plus or minus ten percent!
SOURCE: Philippine Commentary