Warm-up4.4 Designing Experiments to Reduce Variability

In order to assess the effects of exercise on reducing cholesterol, a

researcher sampled 50 people from a local gym who exercise regularly

and 50 people from the surrounding community who do not exercise

regularly. Each subject reported to a clinic to have their cholesterol

measured. The subjects were unaware of the purpose of the study, and

the technician measuring the cholesterol was not aware of whether the

subject exercises regularly or not.

1) What type of study is this?

2) What are the units?

3) What are the conditions of interest being studied?

4) What are some possible error in the sampling that may affect the results?

Student of the day!Block 4

Student of the day!Block 5

Student of the day!Block 6

4.4 Designing Experiments to Reduce Variability

Matched Pair Experimental Design

PKU (phenylketonuria) is a disease where the body has a shortage of an enzyme that aids in the production in dopamine. The symptoms of the disease can be improved with a restricted diet. A study was created to measure the effect of the restricted diet on the subjects’ dopamine levels. Ten subjects with PKU were selected for the study. A measurement of their dopamine levels before and after 10 weeks of the restricted diet. Units? Treatment? Response variable?

Quiz Directions• Start the quiz once you get it. • Every term will not be used and they will not be used more than

once.• Once you are finished, flip your quiz over in front of you and start

the homework 4.4 E#34 and 36.• Once EVERYONE has finished with their quiz, I will give you

directions on finishing the Rolling Down the River Activity.

Both forms there is voluntary response bias, but I did not include voluntary sampling…include this in the word bank

FORM A is missing a blank – Answer this at the bottom10) _______________ is type of sample selection in which personal

views or opinions of the individual doing the sampling enter into the selection.

Finishing Rolling Down the River• Your sheet of paper with explanations on how you didyour SRS, Vertical Stratified, and Horizontal Stratified willbe collected.• You should have also have the Tables from I and II.• Make sure you answered all the questions in completesentences.• Make sure you answered the questions correctly. READTHEM CAREFULLY.• #4, Part 1, Copy the results from your classmates forSRS, Vertical Strata, Horizontal Strata (in order) then create3 box plots. Show your lists in order and how you foundyour 5 number summary.#6 for Part 1: Actual total yield is 5004, the average plot yield is 50

Statistics and A.P. Statistics• 4.4 E # 34 and 36• Next Block will be the Notebook Check: population, sample, sample size, sampling frame, voluntary response bias,convenience sampling, judgment samples, size bias, biased samplingmethods, unrepresentative sample, nonresponse bias, questionnaire biassimple random sample, cluster sample, probability sample, two-stagesample and multistage sample, strata, stratified random sample,lurking variable, confounding variable, experimental study, observationalstudy, control group, blind study, double-blind study, experimental units,randomization of treatment to subjects, replication, factors, levels, Randomized block design, replication, Randomized paired comparisondesign using matching pairs or repeated measures, Blocking and therandomized block design

• Ch. 4 Test will be on the Friday December 2nd