Question

A researcher investigating the effects of distracted driving conducted a study using 27 adults ranging in age from 18 to 21. Participants were asked to watch a computer screen that simulated driving on a busy city street. Participants used a button on the floor as a brake and were instructed to use this brake as they normally would as if they were really driving (i.e., stop signs, cars ahead of them slowing down, etc.). Nine participants were randomly assigned to one of three distracting conditions: 1) Participants were given a cell phone and had to answer/reply text messages received; 2) Participants were asked to have a conversation with a research assistant while “driving.” The assistant read from a prepared set of conversation questions; 3) Participants had no distractions and were allowed to be fully focused on driving safely. An overall score was measured from the driving exercise where higher scores indicated higher risk of getting into an accident. The table below contains the data collected.

Cell Phone: 20 23 21 22 20 18 18

Passenger Conversation: 19 20 21 16 22 18 20

No Distraction: 17 18 15 19 17 20 17

Answer the following questions using the data from the table above.

A. What is the independent variable and levels for the study conducted?

B. What is the dependent variable and scale of measurement (i.e., NOIR)?

C. What is the null hypothesis for the study conducted?

D. Conduct a test of the null hypothesis using a single-factor ANOVA (p = .05). Be sure to properly write your statistical conclusion – “Since F ( , ) = , p <> .05….”

E. Provide an interpretation of your statistical conclusion from part D. Include the variables from the description above.

F. Assume the researcher has no planned comparisons before analyzing the data and is going to look at all possible comparisons after performing the initial ANOVA test. Use the Scheffe Test to maintain the p – value at .05. Carry out a comparison between the Cell Phone distracted group and the No Distraction group. Be sure to properly state your statistical conclusion for this comparison.

G. Provide an interpretation of your statistical conclusion from part F. Include the variables from the description above.

Answer 1

A. Distracted driving is the independent variable and levels for the study conducted.

B. Accident is the dependent variable and scale of measurement.

C.

Null Hypothesis:

Alternative Hypothesis:

Using SPSS:

Give variable name in Variable View:

Click on Values then lables the name of Distracted Driving:

Enter the Data in Data View:

Now Use One Way Anova test:

Steps: Analyze-->Compare Means-->One Way Anova

Select the Accident in Dependent List and Distracted Driving in Factor.

For Post Hoc test or Multiple Comparison Click on Post Hoc.

Then Tick the Scheffe for Multiple Comparsion and Continue and OK.

Output:

(D):

There was a significant effect of Distracted Driving on Accidents at the p<0.05 level for the three conditions F(2,18) = 3.986, p = 0.037.

(E):

Here P-value = 0.037 that is less than 0.05, it's means there is a significant difference effect of Distracted Driving on Accident.

(F):

(G):

Only there is a significant difference between Cell Phone and No Distraction because p-value 0.042 that is less than 0.05.