Simulations AP stat Review

What are the 7 steps for a simulation?

1. Start at the beginning of a random number table and move left to right

2. Look at the digits 1, 2, 3, etc at a time

3. Discuss how the numbers are assigned

4. Discuss if any numbers should be ignored

5. Discuss whether repeated numbers should be ignored

6. Explain when to stop a trial

7. Explain what to do once the values have been selected

What are the 7 steps to design an experiment?

1. List all treatments (including control/ placebo)

2. Does blocking exist? If so be specific

3. Randomization/ Replication of groups/ treatments

4. How will you control sources of variation?

5. Was the study blinded?

6. Explanation for what you will be measuring and comparing at the end of the study

7. Create a diagram whenever possible

Can you blind any type of group other than people?

No, only people can be blinded

Only blind from treatments

How do you know when to block groups?

When there is a known association

Situations exists that is outside of your control (river, forest, etc.)

5 different random sampling techniques

Simple Random Sampling (SRS), Stratified, Cluster, Systematic, Multi-stage

2 types of bias sampling techniques

Volunteer and Convience

The sampling frame is

everyone the surveyor has access to

The population is

everyone the surveyor is interested in

The sample consists of

the participants in the studyA cens

A census is when

you survey everyone in the population

Simple Random Sampling (SRS)

Randomly assign a number to everything in the sampling frame and then randomly select a specific number of individuals using something like a computer program

Stratified

Putting people in groups based on a known common trait (strata) and then randomly selecting a specific number of individuals from each groups using a computer program

Cluster

Use when all of the groups look similar to the population and then assign numbers to groups and randomly select a specific number of groups

Systematic

Using a rule (such as every 10th) to select your sample

Convenience

When the surveyor selects the sample by using a group that he/ she was easy access to

Volunteer (self-selected(

When the people themselves decide to take part in the study; typically the most passionate

Non-response bias

Those who don’t respond have different opinions from those who do (biggest with volunteer)

Response bias

People respond to survey questions, but something is influencing how they respond, or desire to please the researcher (wording/ leading question)

Observational studies don’t…

randomly assign treatments and never prove causation

Retrospective Observational study

Use data that was collected in the past

Prospective Observational study

Gather data as it unfolds

Experimental studies

use random assignment of treatments and prove cause and effect

experimental units

are the people, animals, or objects that are the subjects in the experiment

Explanatory variable

what’s being manipulated in the experiment

When polling

you know a survey is being conducted