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From |
David Hoaglin <dchoaglin@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: Interpretation of Two-sample t test with equal variances? |

Date |
Wed, 20 Mar 2013 15:22:26 -0400 |

Jay, I'm not aware that boxplots make any assumptions. They show what they are intended to show. Their "performance" comes from the way people interpret them. Boxplots of skewed data will tend to have certain characteristics, boxplots of light-tailed data will have other characteristics, and so on. Some patterns suggest bimodal data. David Hoaglin On Wed, Mar 20, 2013 at 2:56 PM, JVerkuilen (Gmail) <jvverkuilen@gmail.com> wrote: > On Wed, Mar 20, 2013 at 12:58 PM, Nick Cox <njcoxstata@gmail.com> wrote: >> >> I grew up, as it were, on box plots, including David's own writings 30 >> or more years ago, but I think they are oversold in total. > > Yes, boxplots are really great in many circumstances, but they have > some built in assumptions, such as unimodality of the distribution, > and in general perform poorly when you have a light-tailed > distribution. I doubt that's the case here, but with only two groups > it's possible to do a lot more. * * 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/

**Follow-Ups**:**Re: st: Interpretation of Two-sample t test with equal variances?***From:*"JVerkuilen (Gmail)" <jvverkuilen@gmail.com>

**References**:**st: Interpretation of Two-sample t test with equal variances?***From:*Gwinyai Masukume <parturitions@gmail.com>

**Re: st: Interpretation of Two-sample t test with equal variances?***From:*Richard Williams <richardwilliams.ndu@gmail.com>

**Re: st: Interpretation of Two-sample t test with equal variances?***From:*Gwinyai Masukume <parturitions@gmail.com>

**R: st: Interpretation of Two-sample t test with equal variances?***From:*"Carlo Lazzaro" <carlo.lazzaro@tiscalinet.it>

**Re: st: Interpretation of Two-sample t test with equal variances?***From:*Gwinyai Masukume <parturitions@gmail.com>

**Re: st: Interpretation of Two-sample t test with equal variances?***From:*David Hoaglin <dchoaglin@gmail.com>

**Re: st: Interpretation of Two-sample t test with equal variances?***From:*Nick Cox <njcoxstata@gmail.com>

**Re: st: Interpretation of Two-sample t test with equal variances?***From:*"JVerkuilen (Gmail)" <jvverkuilen@gmail.com>

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