A high school teacher conducted a test of a new approach to teaching math.Students were given a pretest when their math class began and a posttest at the end of the semester.The students' math performance increased.The teacher learned near the end of the semester,however,that in their science classes the students were using new computer software that included much of the math the teacher covered in his course.Which of the following threats to internal validity does the new computer software represent?
A)selection
B)regression
C)testing
D)history

Question

Quizplus · Accepted Answer

The new computer software used in science classes represents a history threat to internal validity, as it is an external event that occurred during the study and could have influenced the students' math performance improvement.

A High School Teacher Conducted a Test of a New