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From |
Nick Cox <njcoxstata@gmail.com> |

To |
"statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu> |

Subject |
Re: st: How do I demonstrate that a sample is randomly drawn from a population? |

Date |
Mon, 15 Apr 2013 00:45:32 +0100 |

I agree with David. Randomness of sampling has to be judged by knowing how the sample was actually generated. A quantile-quantile plot is the best way to keep track of the similarities or differences between sample and population, in my view. Nick njcoxstata@gmail.com On 14 April 2013 22:14, Yuval Arbel <yuval.arbel@gmail.com> wrote: > David, thanks for your answer. As I noted in my question - I already > tried the difference-of-mean test. I'm not sure, however, this is the > appropriate test for the problem I presented (in your answer - you > said the same thing in different words). > > My educated guess would be - that to demonstrate a random sample - I > need to make some comparison between the population and sample > distribution. The question would still be what exact test do I need - > and what is the appropriate command in stata > > On Sun, Apr 14, 2013 at 1:56 PM, David Greenberg <dg4@nyu.edu> wrote: >> Testing whether the mean of a sample is significantly different from the >> mean of a population is a topic covered in every introductory statistics >> book. However, even if the differences in means is not statistically >> significant, you still have not demonstrated that the sample was, in fact, >> randomly drawn from the given population. David Greenberg, Sociology >> Department, New York University >> >> >> On Sun, Apr 14, 2013 at 3:00 PM, Yuval Arbel <yuval.arbel@gmail.com> wrote: >>> >>> Dear statalisters, >>> >>> I have two files: >>> >>> 1) The first file contains the grades of all population of Open >>> University students. >>> >>> 2) The second file contains the grades of Open University students, >>> who filled a questionnaire via the net. >>> >>> I would like to show that the second file is a random sample drawn >>> from the first file. >>> >>> The question is can I provide a statistical evidence that the sample >>> is indeed random? what are the appropriate commands in stata? >>> >>> P.S. I thought to run the test of difference of means between two >>> populations. Having reconsidered, however, I'm not talking here about >>> two populations, but rather a sample,which is drawn from a given >>> population. >>> >>> As always, your answers will be very much appreciated >>> >>> -- >>> Dr. Yuval Arbel >>> School of Business >>> Carmel Academic Center >>> 4 Shaar Palmer Street, >>> Haifa 33031, Israel >>> e-mail1: yuval.arbel@carmel.ac.il >>> e-mail2: yuval.arbel@gmail.com >>> * >>> * For searches and help try: >>> * http://www.stata.com/help.cgi?search >>> * http://www.stata.com/support/faqs/resources/statalist-faq/ >>> * http://www.ats.ucla.edu/stat/stata/ >> >> > > > > -- > Dr. Yuval Arbel > School of Business > Carmel Academic Center > 4 Shaar Palmer Street, > Haifa 33031, Israel > e-mail1: yuval.arbel@carmel.ac.il > e-mail2: yuval.arbel@gmail.com > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/faqs/resources/statalist-faq/ > * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/

**References**:**st: How do I demonstrate that a sample is randomly drawn from a population?***From:*Yuval Arbel <yuval.arbel@gmail.com>

**Re: st: How do I demonstrate that a sample is randomly drawn from a population?***From:*Yuval Arbel <yuval.arbel@gmail.com>

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