*! version 1.0.3 15dec2022

Title

intcon -- Internal Consistency

Syntax

intcon varlist [if] [in] [weight], [nst]

cont Continuous indexes

ord Ordinal indexes

nst(string) Name of the study (label)

aweights, fweights and pweights are allowed. pweights may not be used with continuous indexes.

Description

This command computes statistical coefficients to evaluate internal consistency. Cronbach's alpha, Armor's theta and McDonald's omega(t)
are computed for continuous indexes, as well as its equivalents for ordinal indexes. At least two numerical variables must be
specified. At least one cont or ord option is needed.

You can click here to pop up a dialog or type db intcon.

Execute net from http://metodo.uab.cat/stata for install.

It is important to keep the commands updated. Execute adoupdate intcon, update to update the intcon command.

Execute adoupdate, update to update all the user-written commands.

This command uses the alpha, factor, factormat and sem Stata commands. It also uses the
alphawgt and
polychoric
user defined programs.

If you find any bugs or want to suggest any improvements, please send an e-mail to: leam@uab.cat.

Examples

. use http://metodo.uab.cat/stata/intcon.dta

. intcon Item1 Item2 Item3 Item4 Item5 Item6, cont ord

Stored results

The command stores the following in r():

Continuous measures

r(alpha) Cronbach's alpha

r(theta) Armor's theta

r(omega) McDonald's omega(t)

Ordinal measures

r(alpha_ord) Ordinal alpha

r(theta_ord) Ordinal theta

r(omega_ord) Ordinal omega

Version

Version 1.0.3 -- 15 December 2022

Authors

JM.Doménech & JB.Navarro

Programmer: R.Sesma

Laboratori d'Estadística Aplicada

Universitat Autònoma de Barcelona

leam@uab.cat

Vancouver reference

Doménech JM, Navarro JB. Internal Consistency: User-written command intcon for Stata [computer program].

V1.0.3. Bellaterra: Universitat Autònoma de Barcelona; 2022.

Available executing from Stata: net from http://metodo.uab.cat/stata

References

Viladrich C, Angulo-Brunet A, Doval E. A journey around alpha and omega to estimate internal consistency reliability. Anal. Psicol. [online]. 2017, 33(3): 755-82. Available from: https://revistas.um.es/analesps/article/view/analesps.33.3.268401