This exercise will give you some preliminary experience with three way cross-tabulation tables. We are starting out "easy" because each of the three variables has only two categories or values. The data (n = 2599) are aggregated from two separate NSF Surveys of Public Understanding of Science and Technology (2006 and 2014). Did American adults become more knowledgeable about a science fact addressing the biological sex of a child over those 8 years?

The table uses the following three variables:

GENDER: 1 = Male  2 = Female  For purposes of this assignment, consider the value "male" to be a "success".

BOYORGRL:  Question: "It is the father's gene that decides whether the baby is a boy or a girl. (Is that true or false?  The answer is true!)
1= Correct answer, True  2 = False (wrong). For purposes of this assignment, consider the (correct) value "true" to be a "success".

YEAR: 2006 or 2014. For purposes of this assignment, consider the value "2014" to be a "success".

This 2 X 2 X 2 table looks as follows:
 

USE THE TABLE ABOVE TO ANSWER THE FOLLOWING QUESTIONS.
PLEASE BE SURE TO ANSWER ALL DESIGNATED PARTS OF A QUESTION.
PLEASE SHOW YOUR WORK ON ALL QUESTIONS.

1. (1 point)  FOR THE TOTAL SAMPLE, what is the first order odds on GENDER--MALE:FEMALE?

2. (1 point) FOR THE TOTAL SAMPLE, what is the first order odds on YEAR, 2014--2006?

3. (1 point) FOR THE TOTAL SAMPLE, what is the first order odds on the DADGENE question--CORRECT: INCORRECT?

4. (1 point) What is the FIRST ORDER CONDITIONAL ODDS for each category of GENDER for "DADGENE"--CORRECT: INCORRECT?

5. (1 point) What is the FIRST ORDER CONDITIONAL ODDS for each category of YEAR for "DADGENE"--CORRECT: INCORRECT?

6. (1 point) FOR THE TOTAL SAMPLE, what is the second order odds ratio for YEAR and DADGENE?
(1 point) Do you think there is an association between year and answers to the DADGENE science question? Why or why not?

7. (1 point) FOR THE TOTAL SAMPLE, what is the second order odds ratio for YEAR and GENDER ?
(1 point) Do you think there is an association between gender and year? Why or why not?

8. (1 point) FOR THE TOTAL SAMPLE, what is the second order odds ratio for GENDER and DADGENE?
(1 point) Do you think there is an association between gender and answers to the DADGENE science question? Why or why not?

9. (1 point) FOR THE TOTAL SAMPLE, what is the third order odds ratio for GENDER, YEAR, and DADGENE?
(2 points) How do you interpret this odds ratio IN WORDS? (HINT: Try calculating some percentages and see if that gives you clues about interpreting the results)?

(1 point) Do you think there is a statistical interaction among gender, year and the science question?
(1 point) Why or why not?

10. (1 point) How many TOTAL beginning degrees of freedom are there in this 2 X 2 X 2 table?

11. (1 point) If we fix the total case base (i.e., constrain the model case base to equal the observed case base), how many degrees of freedom ARE LEFT?

12. Suppose you have a FULLY SATURATED model for GENDER X YEAR X DADGENE.

(1 point) Which parameters have you fixed in this case?
(1 point) What are  the degrees of freedom associated with this fully saturated model?
 
 
 

READINGS AND ASSIGNMENTS

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Susan Carol Losh
January 30 2017