13.1 Introduction

With growth curve modeling we are typically interested in anwsering some basic questions about change:

• How does the construct change over time/age?
• Are there interindividual differences in the level of a process?
• Are there interindividual differences in the rate of change over time?
• How is the level of the construct (at a specific time) related to the rate of change?
• What interindividual characteristic relate to interindividual differences in the level and/or rate of change?
• How are changes in one variable associated with changes in another variable?
• Are there time-dependent relationships in the development of two or more variables?