Key Concepts

In dietary assessment, researchers are often interested in assessing usual dietary intake, which they typically rely on self-report instruments to capture. Two key challenges are inherent in using these instruments:

• Data gathered using these instruments are prone to measurement error (the difference between the true value of a parameter and the value obtained from the reported dietary intake). Knowing how to deal with measurement error when using any type of self-report dietary assessment instrument is critical.
• A second key issue is determining the extent to which a given self-report instrument accurately measures true intake (i.e., provides an unbiased measure of intake). Validation studies are used to evaluate dietary assessment instruments.

This section provides information and guidance on these issues and is important background for the other sections of this website.

• Key Concepts about Measurement Error
• Key Concepts about Validation

The Key Concepts in this section of the Primer contain numerous links to other sections, including the Profiles, Choosing an Approach for Dietary Assessment, Learn More, and the Glossary. Links with dashed underlines will show you terms from the Glossary. Links with solid underlines will take you to other sections of the Primer.