Table with alpha values
alpha_table.RdReturns a data.frame with item analyses for the provided scales.
Usage
alpha_table(
data,
scales,
labels = NULL,
round = 2,
CI = TRUE,
conf_level = 0.95,
check_key = TRUE,
keys = NULL,
keys_from_weights = TRUE,
RMSEA = FALSE,
difficulty = FALSE,
values = NULL,
fa = TRUE
)Arguments
- data
A data Frame
- scales
A list containing vectors with variable names. Each list element defines one scale. Named list elements are used as labels.
- labels
Label names for scales (defaults to named list elements in 'scales').
- round
Rounds values to given decimal position.
- CI
If TRUE confidence intervals are calculated.
- conf_level
Confidence level (e.g. 0.95 for 95 percent).
- check_key
Check_key for the psych::alpha function.
- keys
Optional key argument for the psych::alpha function.
- keys_from_weights
If TRUE, tries to define keys from scaledics "weights" parameter.
- RMSEA
If TRUE RMSEA is calculated.
- difficulty
If TRUE, the difficulty of the item is calculated.
- values
Sets maximum and minimum valid values necessary to calculate item difficulty
- fa
If TRUE, a one factor exploratory factor analyses is calculated and loadings are reported.
Examples
scales <- get_scales(ex_itrf,
Int = scale == "ITRF" & subscale == "Int",
Ext = scale == "ITRF" & subscale == "Ext"
)
alpha_table(ex_itrf, scales = scales, difficulty = TRUE, values = list(c(0, 3)), RMSEA = TRUE)
#> Removed 4 rows because all items were missing.
#> Note. values in brackets depict upper and lower bound of confidence intervals or [min,max] intervals.
#> Scale n n items Alpha CI95% Std.Alph CI95% Homogeneity Discriminations
#> 1 Int 4247 19 .91 [.91, .92] .91 [.91, .92] .36 [.49, .68]
#> 2 Ext 4616 17 .93 [.93, .93] .93 [.93, .93] .44 [.39, .74]
#> Difficulties Means SDs |Loadings| RMSEA
#> 1 [.07, .16] [0.21, 0.48] [0.51, 0.77] [.52, .70] .154
#> 2 [.12, .32] [0.35, 0.95] [0.72, 1.04] [.38, .78] .196