b.- Anova Within group (RM)

From the OBrienKaiser database we perform a withingroup two factors experiment with a within.factor list. In this example we have a design with two repeated factors phase x time (3 x 5) which represents 15 columns in the database (from the third column. See figure below).

For convenience (shorter name) we asign to dat this data base (OBrienKaiser)

dat=OBrienKaiser; head(dat)

Prior to run the Anova.fnc function, in repeated measure designs, we declare previously a list with the within factors variables. The structure of this sintax follows a list with the names of repeated measures factors and theirs levels. Consider the following example.

within.factor= list( phase = c('before','after','following'),

hour= 1:5 )

Unlike between factors designs that must be called by the same name which are in the database being analyzed. In repeated measures designs both the names and levels of repeated measures factors are completely arbitrary.

Anova.fnc(dat, within.factor=within.factor, col.start.rm=3, graphic=F)

As we have a repeated measures design we need to said the function in which column the repeated measures conditions begins. If you look at the prior figure in our example the repeated measures conditions starts in column 3 of our data base. In this case we indicate the argument: col.start.mr = 3. You can also see that we have included the argument graphic = F indicating that we do not want the bar charts with confidence intervals (the default argument is true - T-)

The default for this type of Anova function will give you::

  1. Anova table assuming sphericity.

  2. Mauchly Sphericity test

  3. Greenhose-Geisser and Huynh-Felt non sphericity corrections

  4. Size effects wiht partical and semipartial eta square

  5. Observed power

  6. Descriptives statistics

  7. Barplot with confidence intervals accordig Masson y Loftus(2003) for each estimated fixed effect.