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</o:shapelayout></xml><![endif]--></head><body lang=PT-BR link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Os livros de estatística dizem que existe e dizem também que nem toda a amostra é probabilística. Alertam, porém, que inferência estatística, só nas probabilísticas.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>De:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> abe [mailto:abe-bounces@lists.ime.usp.br] <b>Em nome de </b>Neale El-Dash<br><b>Enviada em:</b> terça-feira, 1 de setembro de 2015 09:59<br><b>Para:</b> abe-l@ime.usp.br<br><b>Assunto:</b> [ABE-L] Amostragem probabilistica existe?<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>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:<o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US style='font-family:"Arial","sans-serif"'>"</span><span lang=EN-US style='font-size:13.5pt;font-family:"Georgia","serif";color:#111111'>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 <em><span style='font-family:"Georgia","serif"'>try</span></em> 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</span><span style='font-family:"Arial","sans-serif"'>"</span><o:p></o:p></p></div><div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Link para o artigo:<o:p></o:p></p></div><div><p class=MsoNormal><a href="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/">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/</a><br clear=all><o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><p class=MsoNormal>-- <o:p></o:p></p><div><div><div><div><div><p class=MsoNormal><o:p> </o:p></p></div><p class=MsoNormal>Knowledge is only part of understanding. Genuine understanding comes from hands-on experience.<o:p></o:p></p></div><div><p class=MsoNormal>(Seymour Papert)<o:p></o:p></p><div><p class=MsoNormal><br>-----------------------------------------------<br>Neale Ahmed El-Dash<br>Doutor em Estatística<br>Celular: +55 19 998893939<br>Email: <a href="mailto:neale.eldash@gmail.com" target="_blank">neale.eldash@gmail.com</a><o:p></o:p></p></div></div></div></div></div></div></div></div></div></body></html>