Biostatistics

Population : Parameter - Quantity describing a population, true value in the population; Doesn’t change

Sample : Estimate/Statistic, Approximation based on sample

Changes from sample to sample

Random sampling can ensure samples are representative and independent

Sampling bias when sampling processes favor some outcomes over others. Bias in sampling may over or underestimate 

Unbiased samples result in sample estimates that reflect population parameters 

Biased data does not

Low sampling error results in sample estimates that are more precise (low variation around the sample mean)