The summary function returns a data frame that provides additional
information. It contains 'Item' and 'Group' columns similiar to the results data
frame as well as a column 'low' corresponding to the sum of levels below
neutral, a column 'high' corresponding to the sum of levels above
neutral, and columns 'mean' and 'sd' corresponding to the mean and
standard deviation, respectively, of the results. The numeric values
are determined by as.numeric which will use the values of the factors.
# S3 method for likert
summary(object, center = (object$nlevels - 1)/2 + 1, ordered = TRUE, ...)the likert class to summarize.
specifies which level should be treated as the center. For example,
center = 3 would use the third level as the center whereas
center = 3.5 would indicate no specific level is the center but
<= 3 are low levels and >= 4 are high levels (i.e. used for forced choice
items or those without a neutral option).
whether the results should be ordered. Currently unsupported for grouped analysis.
currently unused.