What kind of experimental design is being used?

There are two questions in the homework: I have uploaded slides in there starting from slide 19-27 they will give you different types of experimental design pick one of them for each question.
1. In order to test the effectiveness of the debate of the candidates for the president, researchers
randomly contacted 1000 people on the phone. An attempt was made to contact all 1000 one day
before the debate and ask their voting intentions. Only 910 were actually reached by phone; 80
out of the 910 people refused to participate. One day after the debate, 810 of the 910 people were
reached and again asked their voting intentions. In addition they were asked if they had seen the
debate on television. The before-after change of the viewers and non-viewers were compared to
conclude which candidate was more effective in the debate.

What kind of experimental design is being used? Describe relevant potential extraneous variables
in this experiment. Can this experiment design rule out these extraneous variables?

2. In 2018, one of the largest energy firms in the United States noted that its solar panel business
was growing extremely rapidly. This growth had occurred even though the firm never had an
active training program in solar panel sales for its sales force. The top management of the
company believed that by instituting a comprehensive training program, its sales performance
could be further improved. With this goal in mind, the firm’s training department put together a
comprehensive training program. Fifty sales people who had done the greatest volume of solar
panel sales in the first six months of 2018 were selected to participate in the course. In the first
six months of 2019, the average solar panel sales of these sales people who were trained in the
course rose by 15% over the comparable period in 2018. The average sales volume of the sales
people who had not participated in the training program was 20% higher in the first six months
of 2019 as compared to the first six months of 2018. Based on these results the management
concluded that the training program was not useful.

What kind of experimental design is being used? Describe relevant potential extraneous variables
in this experiment. Can this experiment design rule out these extraneous variables?

Last Completed Projects