Instructions: In 2013, Sherman et al. conducted a study to examine how different forms of communication (text messaging, vs. video chat vs. telephone conversation) can influence feelings of closeness and bonding among friends. They instructed participants to come into the lab with their best friend, and randomly assigned them to engage in a 5-minute conversation in one of the three modalities (text message, video chat, or phone conversations). After the conversation, they measured feelings of closeness on a scale of 1-20. Let’s imagine that you decided to replicate this study with 45 participants (15 participants in each group). You can find the data in the questions below.
Your job will be to figure out whether the three groups are different. This is a long one! Take your time figuring out the answers.
Question 10.25 pts
What is the appropriate test statistic to calculate to figure out if the three groups differ?
Group of answer choices
o an ANOVA (F test)
o Dependent sample t-test
o z test
o Independent sample t-test
Question 20.25 pts
State the null hypothesis.
Group of answer choices
o Ho: µ1 = µ2 = µ3
o Ho: X1 ≠ X2 ≠ X3
Question 30.25 pts
State the alternative hypothesis
Group of answer choices
o H1: X1 ≠ X2 ≠ X3
o H1: µ1 = µ2 = µ3
Question 40.25 pts
What is the acceptable level of risk?
Group of answer choices
o p <.05 o P <.1 o P = .5 o P >.05
Here is the dataset for each group. I suggest you download this table
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to help you do your calculation. I included a few calculations in the attached table to help you out.
Data table
Text Message Video Chat Phone Conversation
4 11 10
6 10 8
5 9 9
10 13 10
12 12 5
11 14 3
5 14 12
10 13 4
6 14 8
9 10 8
12 11 9
10 9 10
11 8 5
4 9 10
6 7 4
Question 51 pts
There are lots of steps we need to take before we can calculate the final test statistic. Let's break it down into steps. What is the Sum of Squares (SS) between? See the powerpoint for the formula for this one! Please round your answer to two decimal places.
Question 60.5 pts
Okay, now let's figure out what's the Sum of Squares (SS) within?
Question 70.5 pts
Okay, what's the Mean Squares Within (MSwithin)? See the powerpoint for this formula. Remember, you'll need to calculate the DF to figure this one out!
Question 80.5 pts
What's the Mean Squares Between (MSBetween)?
Question 91.5 pts
Now we're ready to calculate the test statistic (yay!). What is the F statistic value? Round your answer to two decimal places.
Question 101 pts
What is the df between (also known as the df Numerator)?
Group of answer choices
o df = 3
o df = 27
o df = 30
o df = 2
Question 110.5 pts
What is the df within (also known as the df Demominator)?
Question 121 pts
What is the critical value? (Remember, if you cannot find the exact DF denominator value in the table, you should look for the closest number that is there).
Question 130.5 pts
Based on the critical value and the obtained value, do you accept or reject the null hypothesis?
Group of answer choices
o Fail to reject the null hypothesis
o Reject the null hypothesis
Question 140.25 pts
Based on your answer to the previous question, should we run a post hoc test (don't worry, I won't make you calculate them, I just want to know if we should do a post hoc test in this situation).
Group of answer choices
o Yes
o No
Question 151 pts
Write up your results as you would see them in a research paper. Be sure that you include the means and standard deviations for each group in your write-up, as well as a sentence or two explaining the results! See the powerpoint for help with this. You do not need to calculate or include the post-hoc test here.
Although we won’t cover post hoc tests in this course, we will in Methods II. I want to prepare you for them a bit right now. Below is a table that shows computer output for a Tukey Post-Hoc test for the ANOVA you just calculated for your Individual Assignment 13 (comparing the text message group, the phone conversation group, and the video chat group on their ratings of closeness to their friends).
Question 160.25 pts
Based on the Tukey Post-Hoc table (above), is there a significant difference between the text and video groups? You may have to spend some time looking at the table and trying to interpret what each column means.
Group of answer choices
o Yes
o No
Question 170.25 pts
Based on the Tukey Post-Hoc table (above), is there a significant difference between the text and phone groups? You may have to spend some time looking at the table and trying to interpret what each column means.
Group of answer choices
o Yes
o No
Question 180.25 pts
Based on the Tukey Post-Hoc table (above), is there a significant difference between the video and phone groups? You may have to spend some time looking at the table and trying to interpret what each column means.
Group of answer choices
o No
o Yes