Weighted effect coding is a variant of dummy coding to include categorical variables in regression analyses, in which the estimate for each category represents the deviation of that category from the sample mean. The ‘wec’ package for R provides tools to use weighted effect coding.

Manfred te Grotenhuis is currently visiting the Swedish Institute of Social Research (SOFI), where he presented our joint work on Weighted Effect Coding. The recoding of his presentation is available on Manfred’s YouTube channel, and embedded below:

The relevant papers are available here (open access):

• When size matters: advantages of weighted effect coding in observational studies
• A novel method for modelling interaction between categorical variables

More information, as well as software for SPSS and STATA are available from the project website.

ps. Stay updated for an exciting update to the ‘wec’ R package!