the chi square distribution and test for independence l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
The Chi-Square Distribution and Test for Independence PowerPoint Presentation
Download Presentation
The Chi-Square Distribution and Test for Independence

Loading in 2 Seconds...

play fullscreen
1 / 10

The Chi-Square Distribution and Test for Independence - PowerPoint PPT Presentation


  • 78 Views
  • Uploaded on

The Chi-Square Distribution and Test for Independence. Hypothesis testing between two or more categorical variables. Agenda. Wrapping up the t-test program example Chi-Square and Chi-Square test of independence. Chi-Square Distribution.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'The Chi-Square Distribution and Test for Independence' - eileen


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
the chi square distribution and test for independence

The Chi-Square Distribution and Test for Independence

Hypothesis testing between two or more categorical variables

agenda
Agenda
  • Wrapping up the t-test program example
  • Chi-Square and Chi-Square test of independence
chi square distribution
Chi-Square Distribution
  • The chi-square distribution results when independent variables with standard normal distributions are squared and summed.
chi square degrees of freedom
Chi-square Degrees of freedom
  • df = (r-1) (c-1)
      • Where r = # of rows, c = # of columns
      • Thus, in any 2x2 contingency table, the degrees of freedom = 1.
      • As the degrees of freedom increase, the distribution shifts to the right and the critical values of chi-square become larger.
using the chi square test
Using the Chi-Square Test
  • Often used with contingency tables (i.e., crosstabulations)
    • E.g., gender x student
  • The chi-square test of independence tests whether the columns are contingent on the rows in the table.
    • In this case, the null hypothesis is that there is no relationship between row and column frequencies.
      • H0: The 2 variables are independent.
requirements for chi square test
Requirements for Chi-Square test
  • Must be a random sample from population
  • Data must be in raw frequencies
  • Variables must be independent
  • Categories for each I.V. must be mutually exclusive and exhaustive
special cases
Special Cases
  • Fisher’s Exact Test
    • When you have a 2 x 2 table with expected frequencies less than 5.
  • Strength of Association
    • Some use Cramer’s V (for any two nominal variables) or Phi (for 2 x 2 tables) to give a value of association between the variables.
practical examples
Practical Examples:
  • chi2dist.do
  • chisquare.do
  • Auto.dta