ci.2x2.stdmean.mixed {statpsych}R Documentation

Computes confidence intervals of standardized effects in a 2x2 mixed design

Description

Computes confidence intervals for the standardized AB interaction effect, main effect of A, main efect of B, simple main effects of A, and simple main effects of B in a 2x2 mixed factorial design where Factor A is a within-subjects factor, and Factor B is a between-subjects factor. Equality of population variances is not assumed. A square root unweigthed average variance standardizer is used.

Usage

ci.2x2.stdmean.mixed(alpha, y11, y12, y21, y22)

Arguments

alpha

alpha level for 1-alpha confidence

y11

vector of scores at level 1 of A and level 1 of B (group 1)

y12

vector of scores at level 1 of A and level 2 of B (group 2)

y21

vector of scores at level 2 of A and level 1 of B (group 1)

y22

vector of scores at level 2 of A and level 2 of B (group 2)

Value

Returns a 7-row matrix (one row per effect). The columns are:

References

Bonett DG (2008). “Confidence intervals for standardized linear contrasts of means.” Psychological Methods, 13(2), 99–109. ISSN 1939-1463, doi:10.1037/1082-989X.13.2.99.

Examples

y11 <- c(18, 19, 20, 17, 20, 16)
y12 <- c(19, 16, 16, 14, 16, 18)
y21 <- c(19, 18, 19, 20, 17, 16)
y22 <- c(16, 10, 12,  9, 13, 15)
ci.2x2.stdmean.mixed(.05, y11, y12, y21, y22)

# Should return:
#             Estimate adj Estimate        SE          LL         UL
# AB:      -1.95153666  -1.80141845 0.5407442 -3.01137589 -0.8916974
# A:        1.06061775   1.01125934 0.2797699  0.51227884  1.6089567
# B:        1.90911195   1.76225718 0.5758855  0.78039715  3.0378267
# A at b1:  0.08484942   0.07589163 0.4650441 -0.82662027  0.9963191
# A at b2:  2.03638608   1.82139908 0.2995604  1.44925855  2.6235136
# B at a1:  0.93334362   0.86154796 0.5036429 -0.05377836  1.9204656
# B at a2:  2.88488027   2.66296641 0.7477246  1.41936706  4.3503935



[Package statpsych version 1.7.0 Index]