Discussion of Parkinson's experiment (ethics, placebo effect, control).

1. OBJECTIVES 1. 2. 3. HW REMINDERS Ch. 13 # 23, 25, 35, 41 (To Study for Quiz) Parkinson's Experiment Discussion Confounding Factors Quiz Wednesday December 12 Ch. 12 & Ch. 13 UNIT III TEST December 19 (WED) AP Questions Due Friday (12/14) Project Coming soon...

2. Which of the following are true statements about blocking? I. Blocking is to experiment design as stratification is to sampling design II. By controlling certain variables, blocking can make conclusions more specific. III. The paired comparison design is a special case of blocking. (A) I and II (B) I and III (C) II and III (D) I, II, and III (E) None of the above gives the complete set of true responses. (Question taken from Barron's AP Statistics Review Guide 2007 (3rd Edition))

3. Which of the following are true statements about blocking? I. Blocking is to experiment design as stratification is to sampling design II. By controlling certain variables, blocking can make conclusions more specific. III. The paired comparison design is a special case of blocking. (A) I and II (B) I and III (C) II and III (D) I, II, and III (E) None of the above gives the complete set of true responses. (Question taken from Barron's AP Statistics Review Guide 2007 (3rd Edition))

5. BOOK - pg. 307 - 308 CONFOUNDING - the levels of one factor are associated with the levels of another factor. 472 STUDENTS SUBDUED (FALL TERM) ENTHUSIASTIC (SPRING TERM) How much of difference attributed to his demeanor? How much to the students' mental state? HOW MUCH DID YOU LEARN? (1 TO 5) 4.5 2.93

6. LURKING VARIABLE - prior cause of y and x that makes it appear that x may be causing y. CONFOUNDING - associated in a non-causal way with a factor and affects the response Can't tell whether what we observed can be attributed to the factor, or to the confounding variable WE NEED TO CONTROL FOR CONFOUNDING VARIABLES!