Statistical Methods for Psychology

Calculations The calculations for the sums of squares appear in Table 13.2b. Many of these calculations should be familiar, sinc ...

All that we have left to calculate is the sum of squares due to error. Just as in the one- way analysis, we will obtain this by ...

freedom for any interaction is simply the product of the degrees of freedom for the com- ponents of that interaction. Thus,. The ...

where From this model it can be shown that with fixed variables the expected mean squares are those given in Table 13.3. It is a ...

for older ones. The fact that the two lines are not parallel is what we mean when we speak of an interaction. If Condition diffe ...

Many people will argue that if you find a significant interaction, the main effects should be ignored. It is not reasonable, how ...

424 Chapter 13 Factorial Analysis of Variance Table 13.4 Illustration of calculation of simple effects (data taken from Table 13 ...

Calculation In Table 13.4b you can see that is calculated in the same way as any sum of squares. We simply calculate using only ...

show up on only those tasks involving higher levels of processing. This is basically what Eysenck set out to demonstrate. In gen ...

Cognitive Task NS: 27 34 19 20 56 35 23 37 4 30 4 42 34 19 49 DS: 48 29 34 6 18 63 9 54 28 71 60 54 51 25 49 AS: 34 65 55 33 42 ...

A SPSS summary table for a factorial design differs somewhat from others you have seen in that it contains additional informatio ...

one is larger. Here we don’t have enough evidence to conclude that Delayed is different from Nonsmoking, but we dohave enough ev ...

In Experiment 1 an investigator wishes to examine the efficacy of four different treat- ments for post-traumatic stress disorder ...

variable, which are the levels that are of primary interest and would be the same levels he or she would expect to use in a repl ...

Over replications the only variability comes from the last term (eijk), which explains why can be used as the denominator for al ...

estimated by the numerator and denominator in an Fstatistic. Rather than providing a deri- vation of expected mean squares, as I ...

The same kind of argument holds for our test on the interaction, because and the result will be significant only if the interact ...

Nested Designs Now let’s modify our basic study again while retaining the same values of the dependent variable so that we can c ...

we need to look at the expected mean squares when we have a random variable that is nested within a fixed variable. These expect ...

Notice in Table 13.10 that when we have a nested design with a random variable nested within a fixed variable our Fstatistic is ...