Connecting Theory to Methods in Longitudinal Research.

Area of Science:

• Psychology
• Quantitative Psychology
• Research Methodology

Background:

• Longitudinal data collection and analysis methods have advanced significantly.
• Research on psychological processes using longitudinal data is increasing.
• Assessment timing in longitudinal studies is often based on methodological or practical factors rather than psychological theory.

Purpose of the Study:

• To highlight the disconnect between psychological theory and assessment timing in longitudinal research.
• To argue for stronger connections between theory and methods in longitudinal study design.
• To offer solutions for improving the alignment of assessment timing with theoretical models.

Main Methods:

• Review of instances where assessment timing disconnects from theory.
• Discussion of potential solutions for four key longitudinal research questions.
• Focus on scaling time, number of assessments, assessment frequency, and timing of assessments.

Main Results:

• The disconnect between theory and assessment timing leads to misspecified models, interpretive errors, and mixed findings.
• Methodological and practical considerations often override theoretical justifications for assessment timing.
• Lack of explicit justification for methodological decisions is common.

Conclusions:

• Researchers must place higher demands on connecting psychological theories to the methods used in longitudinal research.
• Addressing the disconnect in assessment timing is crucial for advancing psychological science.
• Improved alignment will lead to more accurate models and meaningful conclusions in longitudinal psychological research.