Figure 4.
Dendrogram of cluster analysis using the Ward method for 11 different scaling models based on the distance matrix defined as average absolute differences between country means of models for PISA 2009 reading data.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.