| ds_vpt {splithalfr} | R Documentation |
Example Visual Probe Task (VPT) Measurement Data in JASMIN1 Format
Description
The JASMIN1 VPT distinguished between "test" stimuli, which are in some way assumed to be salient to the participant and "control" stimuli, which are not. Test and control stimuli were presented in pairs, with one left and one right, followed by a probe that was an arrow pointing up or down. Participants needed to indicate whether the arrow pointed up or down. Upon a correct response the next trial started and upon an incorrect response the current trial was repeated. Only the first response to a new trial was logged. This particular VPT was part of the pre-measurement of a cognitive bias modification study. The "test" stimuli were alcoholic beverages and the "control" stimuli were non-alcoholic beverages, selected from the Amsterdam Beverage Picture Set doi:10.1111/acer.12853(Pronk, Deursen, Beraha, Larsen, & Wiers, 2015). The dataset contains one row per trial. This dataset was graciously provided by Marilisa Boffo.
Usage
ds_vpt
Format
An object of class data.frame with 19520 rows and 12 columns.
Details
Overview of columns:
UserID. Identifies participants
patt. Probe-at-test. If "yes", the probe was positioned at the test stimulus. If "no", the probe was positioned at the control stimulus.
phor. Probe horizontal position. Values: "left" or "right"
thor. Test horizontal position. Values: "left" or "right"
keep. If "yes" the probe was superimposed on the stimuli. If "no" the probe replaced the stimuli.
pdir. Probe direction. Values: "up" or "down"
stim. Stimulus
response. Response; 1 = correct, 2 = incorrect, 3 and NA = timeout (no response in 5000 ms), 4 = invalid key
rt. Response time in milliseconds
block. Counts blocks, starting at zero
trial. Counts trials in blocks, starting at zero
block_type. Type of block: "assess" for assessment trials with salient stimuli