The standardized score (z-score) indicates how far a student's performance deviates from the mean in units of standard deviation. This function is applicable only to binary response data.
The score is calculated by standardizing the passage rates: $$Z_i = \frac{r_i - \bar{r}}{\sigma_r}$$ where:
\(r_i\) is student i's passage rate
\(\bar{r}\) is the mean passage rate
\(\sigma_r\) is the standard deviation of passage rates
sscore(U, na = NULL, Z = NULL, w = NULL)# S3 method for default
sscore(U, na = NULL, Z = NULL, w = NULL)
# S3 method for binary
sscore(U, na = NULL, Z = NULL, w = NULL)
A numeric vector of standardized scores for each student. The scores follow a standard normal distribution with:
Mean = 0
Standard deviation = 1
Approximately 68% of scores between -1 and 1
Approximately 95% of scores between -2 and 2
Approximately 99% of scores between -3 and 3
Either an object of class "exametrika" or raw data. When raw data is given,
it is converted to the exametrika class with the dataFormat
function.
Values to be treated as missing values.
Missing indicator matrix of type matrix or data.frame. Values of 1 indicate observed responses, while 0 indicates missing data.
Item weight vector specifying the relative importance of each item.
# using sample dataset
sscore(J5S10)
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