{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

ansmid - Midterm Exam February 2003 ANSWERS Categorical...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Midterm Exam, February 2003, ANSWERS Categorical Data Analysis for Epidemiologic Studies, CHL5407H 1a. Adoption of a Pearson chi-square test is reasonable. Only the degrees of freedom are in question. The Pearson chi-square test should be calculated using two degrees of freedom since there are no observations, and hence no information, in the row reserved for subjects with severely impaired lung function. The expected number of observations in these two cells is zero. How could these cells even be used to calculate the Pearson chi-square test given by χ 2 P = ∑ ∑ ( O - E ) 2 /E ? The expected numbers of observations in all other cells are sufficiently large to support the use of a Pearson chi-square test with two degrees of freedom. 1b. Several different methods of analysis could be used. Here I will only review one of these. Several students discussed more than one method. Only the first of these was graded. Students are encouraged to try and answer the question which was asked. Fisher’s exact test is applicable to analysis of data from an r × c contingency table and so could be used to test for an association between smoking status and lung function. Adoption of this test would still require omitting the row reserved for subjects with severely impaired lung function. One advantage of an exact test is
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern