Friday, November 30, 2012

Two more Statistics videos

This week I have added two new videos to my YouTube Channel - these are based on the Chi-Square Test and the ANOVA test.

Chi-Square Tests (often referred to as Goodness of Fit) are used to compare the difference between expected and observed results. In the video below I outline this using dice. Each dice has six sides, so if it is a fair dice I would expect each number to show up 100 times if I rolled the dice 600 times - this is the expected value. When I actually conduct the experiment, and roll the dice 600 times, I count the observed results and use Chi-Square to compare if there is a significant difference between the observed and the expected data.

The second video is about Analysis of Variance (ANOVA). This is typically used to compare the means of three or more groups. ANOVA analyses variance between the different groups of data, and within each sample Excel needs the "Analysis Toolpak" which is a suite of statistics tools. In this case it will generate an ANOVA table and an F statistic with which we can test for significance using F-distribution tables.

No comments:

Post a Comment