Power Project Home
Intro to nQuery Glossary of Terms Links & Resources nQuery website
Intro to Power
Evaluation
Paired Samples T-test Independent Samples T-test Multiple Regression One Way Analysis of Variance

 

ONE-WAY ANALYSIS OF VARIANCE


This example is based on:
Ball, E. W., & Blachman, B. A. (1991). Does phoneme awareness training in kindergarten make a difference in early word recognition and developmental spelling? Reading Research Quarterly, 26(1), 49-66.


The effects of training in phoneme segmentation and instruction in letter names and sounds on children's reading and spelling skills were measured in Ball and Blachman's study. Eighty-nine kindergarten students were randomly assigned to one of three groups:

Group 1 received training in phoneme segmentation, as well as training in correspondences between letter names and sounds (called the phoneme awareness group).

Group 2 received training in only the letter names and sounds (called the language activities group).

Group 3 received no intervention (called the control group).

Various sub-tests were given to the students in each group. This table presents the means and standard deviations for each group on the sub-tests.

 

Phoneme Awareness

(n=29)

Language Activities

(n=30)

Control

(n=30)

 
M
SD
M
SD
M
SD
Post-test            

Segmentation

24.4
5.8
16.4
4.8
15.4
5.0

Letter Names

21.3
5.1
20.7
5.8
21.7
4.9

Letter Sounds

16.6
5.2
16.5
4.6
13.1
7.1

Woodcock ID

3.2
4.6
1.4
2.5
1.1
3.1

Regular Woods

10.9
8.4
3.9
6.7
2.2
3.7
             
             

Using the data presented in Ball and Blachman's study, we will perform a power analysis using nQuery AdvisorÒ. We will use the means in the segmentation task.