This function can be used to detect exceptionally high or low scores in a vector.
exceptionalScore( x, prob = 0.025, both = TRUE, silent = FALSE, quantileCorrection = 1e-04, quantileType = 8 )
| x | Vector in which to detect exceptional scores. |
|---|---|
| prob | Probability that a score is exceptionally positive or negative;
i.e. scores with a quartile lower than |
| both | Whether to consider values exceptional if they're below
|
| silent | Can be used to suppress messages. |
| quantileCorrection | By how much to correct the computed quantiles; this is used because when a distribution is very right-skewed, the lowest quantile is the lowest value, which is then also the mode; without subtracting a correction, almost all values would be marked as 'exceptional'. |
| quantileType | The algorithm used to compute the quantiles; see
|
A logical vector, indicating for each value in the supplied vector whether it is exceptional.
Note that of course, by definition, prob or 2 * prob percent of
the values is exceptional, so it is usually not a wise idea to remove scores
based on their 'exceptionalness'. Instead, use exceptionalScores(),
which calls this function, to see how often participants answered
exceptionally, and remove them based on that.
exceptionalScore( c(1,1,2,2,2,3,3,3,4,4,4,5,5,5,5,6,6,7,8,20), prob=.05 ); #> [1] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE #> [13] FALSE FALSE FALSE FALSE FALSE FALSE FALSE TRUE