Stat 6020 introduction to biostatistics fall 2005 dr g h rowell
Sponsored Links
This presentation is the property of its rightful owner.
1 / 19

STAT 6020 Introduction to Biostatistics Fall 2005 Dr. G. H. Rowell PowerPoint PPT Presentation


  • 52 Views
  • Uploaded on
  • Presentation posted in: General

STAT 6020 Introduction to Biostatistics Fall 2005 Dr. G. H. Rowell. Class 3. Ch 5: REVIEW from your Homework. Students in the class will take turns defining the terms listed in this presentation that they have listed in their homework.

Download Presentation

STAT 6020 Introduction to Biostatistics Fall 2005 Dr. G. H. Rowell

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


STAT 6020Introduction to BiostatisticsFall 2005Dr. G. H. Rowell

Class 3


Ch 5: REVIEW from your Homework

Students in the class will take turns defining the terms listed in this presentation that they have listed in their homework.

Examples are helpful if you have them included, please mention them.


REVIEW

Ch5: Designing Research, Overview: Observational Study


REVIEW

Ch 5: Designing Research, Overview: Experiment


REVIEW

Ch 5: Some Definitions

  • Observational Study vs. Experiment

  • Prospective vs. Retrospective

  • Longitudinal vs. Cross-sectional

  • Control vs. Treatment


Ch 5: Sources of Variation

  • Variation: control what you can, randomize what you cannot control

  • Cautions:

    • Samples need to represent the population

    • In comparative studies, make groups similar with respect to known sources of variation


Planning a Good Experiment, 2(Cobb, Introduction to Experimental Design, Springer, 1998.)

  • The Content of an Experiment: 3 Decisions to Make


Planning a Good Experiment, 1(Cobb, Introduction to Experimental Design, Springer, 1998.)

  • Three SOURCES of Variability: One We Want and Two We Don’t Want


Planning a Good Experiment, 1(Cobb, Introduction to Experimental Design, Springer, 1998.)

  • Three KINDS of Variability: One We Want, One We Can Live With, and One That Threatens Disaster


REVIEW

Ch 5: Case Study, Section 5.4

  • Replicated Measures

  • Balanced Design

  • Randomization

  • Covariates

  • Sample size


REVIEW

Ch 5: Experiment Terms

  • Bias (Bias vs. Chance Error)

  • Randomization

  • Blinding

  • Replications

  • Sample selection

  • Sample size


Ch 5L Experiment Structure

  • See diagrams on Pages 83 – 85


Ch 5.7: Random Allocation

  • For Hand-in Homework: Name: Randomization SimulationDue Date:  Monday, Sept. 19 at 9:30 AM CSTPossible Points:  20Complete the Randomization Simulation Activity found athttp://mtsu.edu/~smcdanie/I_cubed/Lesson2/lesson2-Home.htm Be sure to submit the "pretest" and the "lesson" and the "feedback" forms.  Note, there is a not a review for this lesson.  Do NOT skip the "tutorial."


Ch 5.7: Random Allocation

  • HOMEWORK: AFTER you complete the randomization simulation, read Sect. 5.7 & define

    • Simple Randomization

    • Block (Restricted) Randomization

    • Stratified Randomization

    • Cluster Randomization

  • Note: Skip Section 5.8 for now.


Ch 5.9: Observational Studies

  • Two Main Types of Observational Study used to investigate Causal Factors

    • Case-Control (retrospective)

    • Cohort (prospective)


Ch 5.10: Case-Control Study

  • Big Picture

    • Identify group with condition (case)

    • Identify group without condition (control)

    • Compare past exposure to factor for the two groups

  • Advantage: relatively simple, quick, inexpensive, valuable with rare conditions

  • Disadvantage: biases can occur

    • Homework: Read 5.10.1 – 5.10.6


Ch 5.11: Cohort Study

  • Big Picture: follow-up study

    • Identify group of subjects of interest

    • Follow them to see what happens (Begin with unaffected observations & wait to see what happens)

  • Advantage: careful measurement

  • Disadvantage: could take a long time for a large enough proportion to be affected (expensive), not good for rare conditions

  • Homework: Read 5.11


Ch 5.12: Cross-sectional Study

  • All information is collected at the same time (subjects contact once)

    • Descriptive Ex: Surveys

    • Investigation of Associations – an alternative to the case-control and cohort approach

  • Advantage: no recall bias, no loss to follow-up, cheap

  • Disadvantage: Cannot draw clear inference of causality

  • Homework: Read 5.12.


Other Ch 5 Homework

  • Read Section 5.13 & 14

  • Work Homework Problems # 1 -3.

  • Check answers in the back of the book.


  • Login