Data And Sampling Distributions

Question 1

Bias

Answer 1

Measurement or sampling errors that are systematic and produced by the measurement or sampling process

Question 2

X-bar and mu

Answer 2

X-bar = the mean of a sample from a population, whereas μ

is used to represent the mean of a population.

Question 3

Selection bias

Answer 3

Practice of selectively choosing data in a way that leads to a conclusion that is misleading or ephemeral

Question 4

Data snooping

Answer 4

Extensive hunting through data until something interesting emerges

Question 5

Vast search effect

Answer 5

If you repeatedly run different models and ask different questions with a large data set, you are bound to find something interesting

Question 6

Target reshuffling

Answer 6

A permutation test to test to validity of predictive associations that a data mining model suggests

Question 7

Typical forms of selection bias

Answer 7

• no random sampling
• cherry-picking data
• selection of time intervals that accentuate a particular statistical effect
• stopping an experiment when the results look interesting

Question 8

Regression to the mean

Answer 8

Phenomenon involving successive measurements on a given variable: extreme observations tend to be followed by more central ones
(Not linear regression)