Difference between revisions of "SOCR EduMaterials AnalysisActivities TwoIndepT"

From SOCR
Jump to: navigation, search
 
 
(9 intermediate revisions by 3 users not shown)
Line 1: Line 1:
==Two Independent Sample T-Test Example==
+
==[[SOCR_EduMaterials_AnalysesActivities | SOCR Analysis]] - Two Independent Sample T-Test Background==
We will demonstrate Two Independent T-Test with a SOCR built-in example.  This example is based on a dataset from the statistical program "R." For more information of the R program, please see [http://cran.r-project.org/ CRAN Home Page]. The dataset used here is "shoes" under R's "MASS" library. In the dataset, ten boys are given to the wear of shoes of materials A and B for one foot. We'd like to find if one material is better than the other.
 
  
 +
Given two groups of data, not necessarily with same sample size, we'd like to test the null hypothesis that the two groups have equal mean. This is a parametric test.
 +
 +
==Two Independent Sample T-Test Example (Pooled Sample Variance) ==
 +
Go to the [http://www.socr.ucla.edu/htmls/ana/TwoIndependentTTest_Analysis.html SOCR Two Independent Sample T-Test Applet]. We will demonstrate Two Independent T-Test with a SOCR built-in example.
 +
This example is based on the data taken from "Mathematical Statistics and Data Analysis" by John A. Rice, Second Edition, Ducbury Press, 1995. (Page 390)
  
 
Here's the steps of the activity:
 
Here's the steps of the activity:
  
'''1.''' Click on '''Two Independent Sample T-Test''' at the left panel's combo box.
+
'''1.''' Click on '''Two Independent Sample T-Test (Poored)''' at the left panel's combo box.
 
<center>[[Image:SOCR_AnalysisActivities_TwoIndepT_Chu_051707_Fig1.gif|700px]]</center>
 
<center>[[Image:SOCR_AnalysisActivities_TwoIndepT_Chu_051707_Fig1.gif|700px]]</center>
  
Line 12: Line 16:
  
  
On the right panel, first click on '''EXAMPLE 3''' and next click on "Data" to retreive the demonstrated example. This is the example we'll be looking at.Note that the data are difference of B - A.
+
On the right panel, first click on '''EXAMPLE 1''' and next click on "Data" to retreive the demonstrated example. This is the example we'll be looking at.  
  
 
<center>[[Image:SOCR_AnalysisActivities_TwoIndepT_Chu_051707_Fig2.gif|700px]]</center>
 
<center>[[Image:SOCR_AnalysisActivities_TwoIndepT_Chu_051707_Fig2.gif|700px]]</center>
  
  
'''2.''' Click on the "'''Mapping'''" button to get to the "'''Mapping'''" panel. Click on '''"ADD"''' under '''VARIABLE 1''' and to '''VARIABLE 2''' add the variables for Two Independent Sample T-Test. We care about the difference, so which on goes to '''VARIABLE 1''' is arbitrary. You can just add column '''A''' to '''VARIABLE 1''' and '''B''' to '''VARIABLE 2'''.
+
'''2.''' Click on the "'''Mapping'''" button to get to the "'''Mapping'''" panel. Click on '''"ADD"''' under '''VARIABLE 1''' and to add '''A''', and click on '''ADD''' under '''VARIABLE 2''' to add '''B'''. This will add the variables for Two Independent Sample T-Test. We care about the difference, so which on goes to '''VARIABLE 1''' or '''VARIALBE 2''' is arbitrary. Here, the computer will set difference = Variable 2 - Variable 1. If you like the subtraction to go the other way around, simple assign '''VARIABLE 1''' and '''VARIABLE 2''' in the opposite way.  
Here, the computer will set difference = Variable 2 - Variable 1. If you like the substraction to go the other way around, simple assign '''VARIABLE 1''' and '''VARIABLE 2''' in a different way.  
 
  
  
Line 24: Line 27:
  
  
'''3.''' Click on "'''Calculate'''" then "'''Result'''" to see the results.
+
'''3.''' Click on "'''Calculate'''" then click on "'''Result'''" to see the results.
  
  
Line 31: Line 34:
  
 
'''Questions for students:''' By looking at the test results, what do you think about the data? What can you say about the two different shoe materials?
 
'''Questions for students:''' By looking at the test results, what do you think about the data? What can you say about the two different shoe materials?
 +
 +
 +
 +
<hr>
 +
 +
{{translate|pageName=http://wiki.stat.ucla.edu/socr/index.php?title=SOCR_EduMaterials_AnalysisActivities_TwoIndepT}}

Latest revision as of 15:16, 23 January 2009

SOCR Analysis - Two Independent Sample T-Test Background

Given two groups of data, not necessarily with same sample size, we'd like to test the null hypothesis that the two groups have equal mean. This is a parametric test.

Two Independent Sample T-Test Example (Pooled Sample Variance)

Go to the SOCR Two Independent Sample T-Test Applet. We will demonstrate Two Independent T-Test with a SOCR built-in example. This example is based on the data taken from "Mathematical Statistics and Data Analysis" by John A. Rice, Second Edition, Ducbury Press, 1995. (Page 390)

Here's the steps of the activity:

1. Click on Two Independent Sample T-Test (Poored) at the left panel's combo box.

SOCR AnalysisActivities TwoIndepT Chu 051707 Fig1.gif


SOCR AnalysisActivities TwoIndepT Chu 051707 Fig1A.gif


On the right panel, first click on EXAMPLE 1 and next click on "Data" to retreive the demonstrated example. This is the example we'll be looking at.

SOCR AnalysisActivities TwoIndepT Chu 051707 Fig2.gif


2. Click on the "Mapping" button to get to the "Mapping" panel. Click on "ADD" under VARIABLE 1 and to add A, and click on ADD under VARIABLE 2 to add B. This will add the variables for Two Independent Sample T-Test. We care about the difference, so which on goes to VARIABLE 1 or VARIALBE 2 is arbitrary. Here, the computer will set difference = Variable 2 - Variable 1. If you like the subtraction to go the other way around, simple assign VARIABLE 1 and VARIABLE 2 in the opposite way.


SOCR AnalysisActivities TwoIndepT Chu 051707 Fig3.gif


3. Click on "Calculate" then click on "Result" to see the results.


SOCR AnalysisActivities TwoIndepT Chu 051707 Fig4.gif


Questions for students: By looking at the test results, what do you think about the data? What can you say about the two different shoe materials?





Translate this page:

(default)
Uk flag.gif

Deutsch
De flag.gif

Español
Es flag.gif

Français
Fr flag.gif

Italiano
It flag.gif

Português
Pt flag.gif

日本語
Jp flag.gif

България
Bg flag.gif

الامارات العربية المتحدة
Ae flag.gif

Suomi
Fi flag.gif

इस भाषा में
In flag.gif

Norge
No flag.png

한국어
Kr flag.gif

中文
Cn flag.gif

繁体中文
Cn flag.gif

Русский
Ru flag.gif

Nederlands
Nl flag.gif

Ελληνικά
Gr flag.gif

Hrvatska
Hr flag.gif

Česká republika
Cz flag.gif

Danmark
Dk flag.gif

Polska
Pl flag.png

România
Ro flag.png

Sverige
Se flag.gif