logging in or signing up T Test johnmarktrent Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 1607 Category: Education License: All Rights Reserved Like it (1) Dislike it (0) Added: October 25, 2009 This Presentation is Public Favorites: 1 Presentation Description A conceptual understanding of the T Test. . . some of these ideas are modified from Trochim, W. . . http://www. socialresearchmethod s. net/research/reshome. htm Check out his web site. . . Comments Posting comment... Premium member Presentation Transcript The t-Test for Differences Between Groups : The t-Test for Differences Between Groups The t-Test : The t-Test Tests whether the means of two groups are statistically different from each other Statistical Analysis : Statistical Analysis Statistical Analysis : Statistical Analysis Control group mean Statistical Analysis : Statistical Analysis Control group mean Treatment group mean Statistical Analysis : Statistical Analysis Control group mean Treatment group mean Is there a difference? What Does Difference Mean? : What Does Difference Mean? What Does Difference Mean? : What Does Difference Mean? Medium variability What Does Difference Mean? : What Does Difference Mean? Medium variability High variability What Does Difference Mean? : What Does Difference Mean? Medium variability High variability Low variability What Does Difference Mean? : What Does Difference Mean? Medium variability High variability Low variability The mean difference is the same for all three cases. What Does Difference Mean? : What Does Difference Mean? Medium variability High variability Low variability Which one shows the greatest difference? What Does Difference Mean? : What Does Difference Mean? A statistical difference is a function of the difference between means relative to the variability. A small difference between means with large variability could be due to chance. Like a signal-to-noise ratio. Low variability Which one shows the greatest difference? What Do We Estimate? : What Do We Estimate? Low variability What Do We Estimate? : What Do We Estimate? Low variability Signal Noise What Do We Estimate? : What Do We Estimate? Low variability Signal Noise Difference between group means = What Do We Estimate? : What Do We Estimate? Low variability Signal Noise Difference between group means Variability of groups = What Do We Estimate? : What Do We Estimate? Low variability Signal Noise Difference between group means Variability of groups = = M1 – M2 s(M1 – M2) What Do We Estimate? : What Do We Estimate? Low variability Signal Noise Difference between group means Variability of groups = M1 – M2 s(M1 – M2) = = t-value What Do We Estimate? : What Do We Estimate? The t-test, one-way Analysis of Variance (ANOVA) and a form of regression all test the same thing and can be considered equivalent alternative analyses. The regression model is emphasized here because it is the most general. Low variability You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
T Test johnmarktrent Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 1607 Category: Education License: All Rights Reserved Like it (1) Dislike it (0) Added: October 25, 2009 This Presentation is Public Favorites: 1 Presentation Description A conceptual understanding of the T Test. . . some of these ideas are modified from Trochim, W. . . http://www. socialresearchmethod s. net/research/reshome. htm Check out his web site. . . Comments Posting comment... Premium member Presentation Transcript The t-Test for Differences Between Groups : The t-Test for Differences Between Groups The t-Test : The t-Test Tests whether the means of two groups are statistically different from each other Statistical Analysis : Statistical Analysis Statistical Analysis : Statistical Analysis Control group mean Statistical Analysis : Statistical Analysis Control group mean Treatment group mean Statistical Analysis : Statistical Analysis Control group mean Treatment group mean Is there a difference? What Does Difference Mean? : What Does Difference Mean? What Does Difference Mean? : What Does Difference Mean? Medium variability What Does Difference Mean? : What Does Difference Mean? Medium variability High variability What Does Difference Mean? : What Does Difference Mean? Medium variability High variability Low variability What Does Difference Mean? : What Does Difference Mean? Medium variability High variability Low variability The mean difference is the same for all three cases. What Does Difference Mean? : What Does Difference Mean? Medium variability High variability Low variability Which one shows the greatest difference? What Does Difference Mean? : What Does Difference Mean? A statistical difference is a function of the difference between means relative to the variability. A small difference between means with large variability could be due to chance. Like a signal-to-noise ratio. Low variability Which one shows the greatest difference? What Do We Estimate? : What Do We Estimate? Low variability What Do We Estimate? : What Do We Estimate? Low variability Signal Noise What Do We Estimate? : What Do We Estimate? Low variability Signal Noise Difference between group means = What Do We Estimate? : What Do We Estimate? Low variability Signal Noise Difference between group means Variability of groups = What Do We Estimate? : What Do We Estimate? Low variability Signal Noise Difference between group means Variability of groups = = M1 – M2 s(M1 – M2) What Do We Estimate? : What Do We Estimate? Low variability Signal Noise Difference between group means Variability of groups = M1 – M2 s(M1 – M2) = = t-value What Do We Estimate? : What Do We Estimate? The t-test, one-way Analysis of Variance (ANOVA) and a form of regression all test the same thing and can be considered equivalent alternative analyses. The regression model is emphasized here because it is the most general. Low variability