|
Summary For Nominal Model
|
Statistical Model Using Nominal Scale
 Model
There are many models which can be employed. The one chosen as being the most likely to be used is the model. To apply the model you must have data which can be divided into two groups such as men/women, red chickens/white chickens, etc. The observations must be forced into only two choices such as germinate/did not germinate, hatched/did not hatch, above the median/below the median, etc. The model is as follows:
The worksheet needed to collect the data would take the following form:
Worksheet I
| |
1st Choice |
2nd Choice |
Group Sums |
| 1st Group |
a |
b |
a + b |
| 2nd Group |
c |
d |
c + d |
Choice Sums |
a + c |
b + d |
n |
A hypothesis to be tested might be: there is no significant difference between men and women regarding their preference for coke or pepsi.
Demonstration Worksheet I
| |
Coke |
Pepsi |
Group Sums |
| Men |
10
a |
10
b |
20
a + b |
| Women |
5
c |
15
d |
20
c + d |
Choice Sums |
15
a + c |
25
b + d |
40
n |
Tabled values can be found through the use of the -table (Page 95). Two decisions have to be made when using the -table. One is the level of significance, while the second is the degrees of freedom.
The level of significance will be the .05 level, thus giving a chance of error of one out of twenty. Thus, the .05 column is the selected point of reference. The process for determining the degrees of freedom requires us to take the columns minus one times the rows minus one. Since there will always be two columns and two rows the degrees of freedom will always be one. To use the table go down the .05 column on the -table to one degree of freedom and the related value for is 3.841.
The hypothesis will be accepted if a computed of less than 3.841 is calculated, when the formula is employed. The hypothesis will be rejected if a computed greater than 3.841 is calculated.
After comparison of the computed to the tabled , the hypothesis is accepted because the computed of 1.706 is less than the tabled of 3.841. Therefore, the conclusion is that men and women do not differ significantly in their preference for coke and pepsi.
(Individual Practice: Assume Cherry Bell and White Icicle radishes are to be germinated. Flats of 100 seeds are planted for each of the radishes. At the end of the germination period it was found that 85 of the Cherry Bell and 72 of the White Icicle radishes had germinated. Was there a significant difference in the germination rates?)
For more information please contact the CE/CE Online
The University of Tennessee at Martin is not responsible for the information or views expressed here.
Statistics For Educational Projects Home Page
Wednesday, 13-Jul-2005 13:42:34 CDT
|
