In: Statistics and Probability
An educational psychologist wants to know if length of time and
type of training affect learning simple fractions. Fifth graders
were randomly selected and assigned to different times (from 1 to 3
hours) and different teaching conditions (old method vs. meaningful
method). All students were then tested on the "fractions" subtest
of a standard arithmetic test. What can the psychologist conclude
with α = 0.01?
Time | |||
Train | one hr | two hrs | three hrs |
old | 5 6 7 |
6 7 7 |
8 9 10 |
meaningful | 6 7 11 |
9 10 11 |
7 9 10 |
Using the SPSS results, compute the
corresponding effect size(s) and indicate magnitude(s).
Train: η2
= ; ---Select--- na trivial effect
small effect large effect
Time: η2
= ; ---Select--- na trivial effect
small effect large effect
Interaction: η2
= ; ---Select--- na trivial effect
small effect large effect
Anova: Two-Factor With Replication | ||||||
SUMMARY | one hr | two hrs | three hrs | Total | ||
old | ||||||
Count | 3 | 3 | 3 | 9 | ||
Sum | 18 | 20 | 27 | 65 | ||
Average | 6 | 6.666667 | 9 | 7.222222 | ||
Variance | 1 | 0.333333 | 1 | 2.444444 | ||
meaningful | ||||||
Count | 3 | 3 | 3 | 9 | ||
Sum | 24 | 30 | 26 | 80 | ||
Average | 8 | 10 | 8.666667 | 8.888889 | ||
Variance | 7 | 1 | 2.333333 | 3.361111 | ||
Total | ||||||
Count | 6 | 6 | 6 | |||
Sum | 42 | 50 | 53 | |||
Average | 7 | 8.333333 | 8.833333 | |||
Variance | 4.4 | 3.866667 | 1.366667 | |||
ANOVA | ||||||
Source of Variation | SS | df | MS | F | P-value | F crit |
Sample | 12.5 | 1 | 12.5 | 5.921053 | 0.031541 | 9.330212 |
Columns | 10.77778 | 2 | 5.388889 | 2.552632 | 0.119209 | 6.926608 |
Interaction | 10.33333 | 2 | 5.166667 | 2.447368 | 0.128404 | 6.926608 |
Within | 25.33333 | 12 | 2.111111 | |||
Total | 58.94444 | 17 |
Train: η2 =SS(train)/SS(ttoal) =12.50/58.9444 =0.2121 , medium effect
TIme: η2 =10.7778/58.9444 =0.1828 medium effect
Interaction: η2 = 10.3333/58.9444 =0.1753 medium effect
d)
There is no training difference in learning factions.
There is no time difference in learning fraction.
.There is no training by time interaction in learning fractions