score.transform {CTT} | R Documentation |
The function transforms the score metric by setting new scales' mean, standard deviation, and normalizing the distribution.
score.transform(scores, mu.new = 0, sd.new = 1, normalize = FALSE)
scores |
Vector for examinee scores |
mu.new |
Desired mean of the scale |
sd.new |
Desired standard deviation of scales |
normalize |
If normailize=True, the score will be normalized applying the inverse of the cumulative distribution function of the normal distribution to the respondents percentile score. |
The function returns a list with two vectors: new.scores is the transformed score and p.scores is the percentile rank of every examinee. If normalize=TRUE than percentile scores are used to create a roughly normal distribution by applying an inverse cumulative normal distribution function to the p.scores.
John T. Willse, Zhan Shu
# Example data provided with package data(CTTdata) data(CTTkey) # Data scored to demonstrate function scores <- score(CTTdata,CTTkey)$score # obtain the scores # the targeted mean=3, standard deviation=1 score.transform(scores,3,1) # the score should be transformed by normalized precentile score.transform(scores,3,1,TRUE)