What contributions to the science and practice of ABA did this article provide?

/in /by

What contributions to the science and practice of ABA did this article provide? In other words, what was the main take away point(s) of this article?

Within the article “THE EFFECTS OF TACT AND LISTENER TRAINING ON THE EMERGENCE OF BIDIRECTIONAL INTRAVERBAL RELATIONS” by Petursdottir et al. (2008) may I receive help with the following questions.