Statistics Experimental Design

A quantity calculated from the observations in a SAMPLE.

• Parameter

• Study

• Statistic

• Observation

Every possible group of units of the required size has the same chance of being the selected sample as any other sample of the same size.

• Simple Random 

• Thoughtful

• Typical

• Proportional

the women at Texas A&M are numbered 1 to 21, 271. A computer generates 225 unique random numbers. The women are contacted and are asked their favorite school tradition. Which sampling design best describes the scenario.

• SRS

• Systematic Random Sample

• Stratified Random Sample

• Cluster Random Sample

Texas is divided into 20 education regions (Fort Worth is region 11). A state senator randomly selects two regions and examines the graduation rates of all high schools in those two regions. Which sample design best describes the scenaro

• SRS

• voluntary Response Sample

• Stratified Random Sample

• Cluster Random Sample

An ​ (a)   does not have treatments imposed.

An ​ (b)   has treatments imposed.

• Observational Study

• Experiment

To investigate whether standing up while studying affects performance in an algebra class, a teacher assigns half of the 30 students in his class to stand up while studying and assigns the other half to not stand up while studying. Which of the following best describes this plan?

• This is an observational study

• This is an experiment

• This is a stratified random sample

• This is a cluster sample

True or False: all samples lead to a good prediction about an entire population.

• True

• False

A market research company wishes to find out whether the population of students at a university prefers Starbucks or Dunkin Donuts. A random sample of students is selected, and each student is asked first to try both but the order they try them is randomly decided with a coin toss (heads: Starbucks, then Dunkin. tails: vice versa). They then indicate which brand they prefer. This is an example of

• completely randomized experiment

• observational study

• stratified sample

• matched pairs experiment

To investigate the effectiveness of an herbal medication for pain relief, a researcher randomly selected 80 patients who were undergoing physical therapy while recovering from an injury. Of the patients, 40 had knee injuries, 16 had arm injuries, and 24 had foot injuries. The researcher will use two treatments for the investigation: the herbal medication and a standard medication. After the patients are on the medication for two weeks, the amount of pain reduction will be measured for each patient. Which of the following best describes why a randomized block design is appropriate for the investigation?

• The 80 patients were selected at random from all patients undergoing physical therapy while recovering from an injury.

• The sample size was greater than 30.

• Each patient will be randomly assigned to either the herbal medication or the standard medication.

• Blocking on injury type will help to separate natural variability from differences due to injury type.

• Each patient assigned to the herbal medication will be paired with a patient assigned to the standard medication.

What kind of experiment is shown in the picture?

• Randomized Block Design

• Completely Randomized Design

• Matched Pairs

• SRS