Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Chi-square test - I do not understand the results :-&

  1. Feb 11, 2014 #1
    In one case I get the results as a significant difference in the other with the same dana, the difference is not significant.


    Data sample
    A B
    I 5 8
    II 4 28

    http://imageshack.com/a/img542/467/o61k.jpg [Broken]

    Same data and got significant difference

    http://imageshack.com/a/img200/7366/y1le.jpg [Broken]

    Where I'm wrong? :frown:
     
    Last edited by a moderator: May 6, 2017
  2. jcsd
  3. Feb 11, 2014 #2

    Stephen Tashi

    User Avatar
    Science Advisor

    The images don't say what kind of chi-square test is being done.

    Try using various options for chi-square tests on the page http://graphpad.com/quickcalcs/contingency1/. Different statistical tests on the same data may give different conclusions.
     
  4. Feb 11, 2014 #3

    FactChecker

    User Avatar
    Science Advisor
    Gold Member

    The second one says it does not apply a Yates correction. It's results are just barely significant at the 95% level. The first test may apply the correction and the result might become insignificant or it may use a different level than 95%.
     
  5. Feb 12, 2014 #4
    Thank you, here is little more data; I used chi-square (χ2) test to investigate the statistical significance of differences of opinion about the students offered the choice of extra-curricular activities with regard to gender and school achievement, ie the most recently completed assessment of students in the English language.

    Can I (completed by SPSS) results interpreted as: no statistically significant differences based on gender.?

    http://imageshack.com/a/img837/3372/0wv6.jpg [Broken]
     
    Last edited by a moderator: May 6, 2017
  6. Feb 12, 2014 #5

    FactChecker

    User Avatar
    Science Advisor
    Gold Member

    The test tried to prove that there was a difference with 95% confidence. It barely succeeded by Pearson chi-squared and barely failed by the other statistics tests. You should NOT conclude that it proved there was no difference. It was not trying to prove that.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Chi-square test - I do not understand the results :-&
  1. Chi-Squared Test (Replies: 1)

Loading...