item.reverse {misty} | R Documentation |
Reverse Code Scale Item
Description
This function reverse codes inverted items, i.e., items that are negatively worded.
Usage
item.reverse(..., data = NULL, min = NULL, max = NULL, keep = NULL, append = TRUE,
name = ".r", as.na = NULL, table = FALSE, check = TRUE)
Arguments
... |
a numeric vector for reverse coding an item, matrix or data frame
for reverse coding more than one item. Alternatively, an expression
indicating the variable names in |
data |
a data frame when specifying one or more variables in the
argument |
min |
an integer indicating the minimum of the item (i.e., lowest possible scale value). |
max |
an integer indicating the maximum of the item (i.e., highest possible scale value). |
keep |
a numeric vector indicating values not to be reverse coded. |
append |
logical: if |
name |
a character string or character vector indicating the names
of the reverse coded item. By default, variables are named with the ending
|
as.na |
a numeric vector indicating user-defined missing values, i.e. these
values are converted to |
table |
logical: if |
check |
logical: if |
Details
If arguments min
and/or max
are not specified, empirical minimum
and/or maximum is computed from the data Note, however, that reverse coding
might fail if the lowest or highest possible scale value is not represented in
the data That is, it is always preferable to specify the arguments min
and max
.
Value
Returns a numeric vector or data frame with the same length or same number of
rows as ...
containing the reverse coded scale item(s).
Author(s)
Takuya Yanagida takuya.yanagida@univie.ac.at
References
Rasch, D., Kubinger, K. D., & Yanagida, T. (2011). Statistics in psychology - Using R and SPSS. New York: John Wiley & Sons.
See Also
item.alpha
, item.omega
, rec
,
item.scores
Examples
dat <- data.frame(item1 = c(1, 5, 3, 1, 4, 4, 1, 5),
item2 = c(1, 1.3, 1.7, 2, 2.7, 3.3, 4.7, 5),
item3 = c(4, 2, 4, 5, 1, 3, 5, -99))
# Example 1a: Reverse code item1 and append to 'dat'
dat$item1r <- item.reverse(dat$item1, min = 1, max = 5)
# Example 1b: Alternative specification using the 'data' argument
item.reverse(item1, data = dat, min = 1, max = 5)
# Example 2: Reverse code item3 while keeping the value -99
dat$item3r <- item.reverse(dat$item3, min = 1, max = 5, keep = -99)
# Example 3: Reverse code item3 while keeping the value -99 and check recoding
dat$item3r <- item.reverse(dat$item3, min = 1, max = 5, keep = -99, table = TRUE)
# Example 4a: Reverse code item1, item2, and item 3 and attach to 'dat'
dat <- cbind(dat,
item.reverse(dat[, c("item1", "item2", "item3")],
min = 1, max = 5, keep = -99))
# Example 4b: Alternative specification using the 'data' argument
item.reverse(item1:item3, data = dat, min = 1, max = 5, keep = -99)