In danilinares/quickpsy: Fits Psychometric Functions for Multiple Groups

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)

Parameters comparisons using bootstrap

You need to specify that would like to perform paircomparisons (in older versions of quickpsy the comparisons are performed by default)

library(quickpsy)

fit <- quickpsy(qpdat, phase, resp, grouping = c("participant", "cond"),
                paircomparisons = TRUE, 
                B = 30) 

plot(fit, color = cond)

All the possible pair comparisons across parameters are include in the output data frame par_dif. If, for example, we want to compare the parameters across conditions for each participant we need the following subset of the data frame

library(dplyr)

fit$par_dif %>% filter(participant == participant2)

dif corresponds to the difference in parameters. difinfand difsup correspond to the limits of the bootstrap confidence intervals (default 95%). Confidence intervals that do not include the zero suggests than the parameters differ. In this case p1 (the parameter of location) seems to differs across conditions for all participants. p2 only seems to differ across conditions for Participant 1.

To reduce computation time, we only included 30 bootstrap samples, but you will need to include much more.

Threholds comparisons using bootstrap

The bootstrap differences across thresholds are included in thresholds_dif

fit$thresholds_dif %>% filter(participant == participant2)

danilinares/quickpsy documentation built on Feb. 13, 2023, 8:44 p.m.