scdhlm (version 0.3)

effect_size_ABk: Calculates HPS effect size

Description

Calculates the HPS effect size estimator based on data from an (AB)^k design, as described in Hedges, Pustejovsky, & Shadish (2012). Note that the data must contain one row per measurement occasion per subject.

Usage

effect_size_ABk(outcome, treatment, id, phase, time, phi, rho)

Arguments

outcome

Vector of outcome data. May not contain any missing values.

treatment

Vector of treatment indicators. Must be the same length as outcome.

id

factor vector indicating unique cases. Must be the same length as outcome.

phase

factor vector indicating unique phases (each containing one contiguous control condition and one contiguous treatment condition). Must be the same length as outcome.

time

vector of measurement occasion times. Must be the same length as outcome.

phi

Optional value of the auto-correlation nuisance parameter, to be used in calculating the small-sample adjusted effect size

rho

Optional value of the intra-class correlation nuisance parameter, to be used in calculating the small-sample adjusted effect size

Value

A list with the following components

M_a

Matrix reporting the total number of time points with data for all ids, by phase and treatment condition

M_dot

Total number of time points used to calculate the total variance (the sum of M_a)

D_bar

numerator of effect size estimate

S_sq

sample variance, pooled across time points and treatment groups

delta_hat_unadj

unadjusted effect size estimate

phi

corrected estimate of first-order auto-correlation

sigma_sq_w

corrected estimate of within-case variance

rho

estimated intra-class correlation

theta

estimated scalar constant

nu

estimated degrees of freedom

delta_hat

corrected effect size estimate

References

Hedges, L. V., Pustejovsky, J. E., & Shadish, W. R. (2012). A standardized mean difference effect size for single case designs. Research Synthesis Methods, 3, 224-239. doi:10.1002/jrsm.1052

Examples

data(Lambert)
with(Lambert, effect_size_ABk(outcome, treatment, case, phase, time))
   
data(Anglesea)
with(Anglesea, effect_size_ABk(outcome, condition, case, phase, session))