[ABE-L] Amostragem probabilistica existe?

[Neale El-Dash]

Segue um artigo do Gelman publicado no Washington Post sobre pesquisas
eleitorais. O comeco do artigo discute alguns detalhes metodologicos sobre
pesquisas telefonicas/online feitas nos EUA. Mas o final vale pra qualquer
lugar, qualquer metodologia. Segue um paragrafo que eu gosto bastante, e
resume tambem minha opiniao sobre o assunto:

"In real life there are no probability samples of humans. With survey
response rates below 10 percent, there is no way to know the probability of
an individual being included in the sample. You can know the probability
that the survey organization will *try* to reach a person — that’s easy, it
just depends on exactly how the address or telephone number or e-mail is
sampled from a given list. But it’s impossible to know the probability that
this person will actually be included in the sample, as this depends on the
probability that the person is reached, multiplied by the probability that
he or she agrees to respond, given that he or she is reached. And neither
of these two probabilities is ever known"

Link para o artigo:
http://www.washingtonpost.com/blogs/monkey-cage/wp/2015/08/31/heres-why-you-should-worry-about-the-polls-for-the-2016-u-s-elections-and-beyond/

-- 

Knowledge is only part of understanding. Genuine understanding comes from
hands-on experience.
(Seymour Papert)

-----------------------------------------------
Neale Ahmed El-Dash
Doutor em Estatística
Celular: +55 19 998893939
Email: neale.eldash em gmail.com
-------------- Próxima Parte ----------
Um anexo em HTML foi limpo...
URL: <https://lists.ime.usp.br/archives/abe/attachments/20150901/3dbfd521/attachment.html>