Given a Laboratory Study That Compared Learning from Text in Two

Multiple Choice

Given a laboratory study that compared learning from text in two conditions, one with underlining of important terms and one without underlining, found that the underlining group did better on factual items; Marina conducted a study with tenth-grade history students and compared one group that read a chapter with the important text underlined and one group that read a chapter without any underlining. In her study she found no effects for the underlining.
-Marina's findings may indicate that the underlining treatment has

A) low internal reliability.
B) low external reliability.
C) low internal validity.
D) low external validity.