EDA CHAP 6-7

Statistical inference

always focuses on drawing conclusions about one or more parameters of a population. An important part of this process is obtaining estimates of the parameters.

Point estimation

is the process of using the data available to estimate the unknown value of a parameter

Population

refers to the entire group that we want to study

Sample

refers to a smaller group

PARAMETER

value we are trying to estimate

statistic

the value calculated from the sample is called

sampling distribution

Distribution of a statistic from all possible samples.

UNBIASED ESTIMATOR

An estimator is said to be unbiased if its expected value equals the true population parameter

variance of a point estimator

measures how much the estimator varies from one random sample to another

standard error

When the numerical value or point estimate of a parameter is reported, it is usually desirable to give some idea of the precision of estimation.

Mean Square Error (MSE)

measures the average squared difference between the estimated values and the true parameter value. measures how close the estimated values are to the true value of a parameter.