_____________ is a statistical technique used to determine how well items mathematically group together,thus indicating similarity and the measurement of a common construct.

A) Item analysis
B) Validity coefficient
C) Content validity ratio
D) Factor analysis

Factor analysis is the statistical technique used to determine how well items mathematically group together. It helps in identifying the underlying factors or dimensions that contribute to the similarity or common construct of the items in a given dataset. This analysis allows the researcher to reduce the complexity of the data and identify the key variables that are involved in measuring a particular construct. Thus, factor analysis is a valuable tool in exploratory research and helps in developing new theories or refining existing ones.