Suppose an experimental group is being taught letters of the alphabet as a treatment. At about the same time, the students are watching an educational program on television, from which they learn the names of the letters. What is the name of the threat that this problem illustrates?

Question

Quizplus · Accepted Answer

This problem illustrates the threat of history, as there is an outside event (the educational program on television) that could affect the students' ability to learn the letters of the alphabet.

Suppose an Experimental Group Is Being Taught Letters of the Alphabet