Preprocessing {AATtools}  R Documentation 
Preprocessing rules
Description
These are preprocessing rules that can be used in aat_splithalf, aat_bootstrap, and aat_compute.
The following rules are to be used for the
trialdropfunc
argument. The way you handle outliers for the reliability computation and bootstrapping more broadly should mimic the way you do it in your regular analyses. It is recommended to exclude outlying trials when computing AAT scores using the mean doubledfference scores and regression scoring approaches, but not when using dscores or median doubledifference scores.
prune_nothing
excludes no trials (default) 
trial_prune_3SD
excludes trials deviating more than 3SD from the mean per participant. 
trial_prune_3MAD
excludes trials deviating more than 3 median absolute deviations from the median per participant. 
trial_prune_grubbs
applies a Grubbs' test to the data, removing one outlier at a time until the test is no longer significant. 
trial_prune_SD_dropcases
removes trials deviating more than a specific number of standard deviations from the participant's mean, and removes participants with an excessive percentage of outliers. Required arguments:
trialsd
 trials deviating more thantrialsd
standard deviations from the participant's mean are excluded (optional; default is 3) 
maxoutliers
 participants with a higher percentage of outliers are removed from the data. (optional; default is .15)


trial_recode_SD
recodes outlying reaction times to the nearest nonoutlying value, with outliers defined as reaction times deviating more than a certain number of standard deviations from the participant's mean. Required argument:
trialsd
 trials deviating more than this many standard deviations from the mean are classified as outliers.


trial_prune_percent_subject
andtrial_prune_percent_sample
remove trials below and/or above certain percentiles, on a subjectbysubject basis or samplewide, respectively. The following arguments are available:
lowerpercent
anduppperpercent
(optional; defaults are .01 and .99).


The following preprocesing rules are to be used for the
errortrialfunc
argument. They determine what is to be done with errors  remove or recode?
prune_nothing
removes no errors (default). 
error_replace_blockmeanplus
replaces error trial reaction times with the block mean, plus an arbitrary extra quantity. If used, the following additional arguments are required:
blockvar
 Quoted name of the block variable (mandatory) 
errorvar
 Quoted name of the error variable, where errors are 1 or TRUE and correct trials are 0 or FALSE (mandatory) 
errorbonus
 Amount to add to the reaction time of error trials. Default is 0.6 (recommended byGreenwald, Nosek, & Banaji, 2003
)


error_prune_dropcases
removes errors and drops participants if they have more errors than a given percentage. The following arguments are available:
errorvar
 Quoted name of the error variable, where errors are 1 or TRUE and correct trials are 0 or FALSE (mandatory) 
maxerrors
 participants with a higher percentage of errors are excluded from the dataset. Default is .15.


These are preprocessing rules to be used for the
casedropfunc
argument. The way you handle outliers here should mimic the way you do it in your regular analyses.
prune_nothing
excludes no participants (default) 
case_prune_3SD
excludes participants deviating more than 3SD from the sample mean.

Usage
prune_nothing(ds, ...)
trial_prune_percent_subject(
ds,
subjvar,
rtvar,
lowerpercent = 0.01,
upperpercent = 0.99,
...
)
trial_prune_percent_sample(
ds,
rtvar,
lowerpercent = 0.01,
upperpercent = 0.99,
...
)
trial_prune_3SD(ds, subjvar, rtvar, ...)
trial_prune_3MAD(ds, subjvar, rtvar, ...)
trial_prune_SD_dropcases(
ds,
subjvar,
rtvar,
trialsd = 3,
maxoutliers = 0.15,
...
)
trial_recode_SD(ds, subjvar, rtvar, trialsd = 3, ...)
trial_prune_grubbs(ds, subjvar, rtvar, ...)
case_prune_3SD(ds, ...)
error_replace_blockmeanplus(
ds,
subjvar,
rtvar,
blockvar,
errorvar,
errorbonus,
...
)
error_prune_dropcases(ds, subjvar, errorvar, maxerrors = 0.15, ...)
Arguments
ds 
A data.frame. 
... 
Other arguments (ignored). 
subjvar 
The name of the subject variable. 
rtvar 
The name of the reaction time variable. 
lowerpercent , upperpercent 
for 
trialsd 
The amount of deviation from the participant mean (in SD) after which a trial is considered an outlier and excluded (defaults to 3). 
maxoutliers 
for 
blockvar 
The name of the block variable. 
errorvar 
The name of the error variable. 
errorbonus 
for 
maxerrors 
for 