A true value, also called a true score, is a psychometric concept that refers to the measure that would have been observed on a construct were there not any error involved in its measurement. Symbolically, this often is represented by X = T + e, where T is the (error-free) true value, e is the error in measurement, and X is the observed score. For example, a survey respondent's true value (t) on a measure (e.g., a 5-item Likert scale measuring attitudes toward her ancestor's native land) might be 13, but her observed score (X) on a given day may be 15 or 17 or 10. There are many reasons why the observed score may deviate from the true value, but the researcher will rarely ...