sampling technique line icons collection. population, sample, randomization, probability, non-probability

vector icon line sign population sample randomization probability nonprobability stratification cluster systematic convenience quota snowball purposive representative bias margin of error inference variability precision sampling frame unit analysis confidence interval power reliability validity size oversampling undersampling outlier response rate analytic generalizability distribution exclusion criteria cohort longitudinal retrospective crosssectional multistage proportional allocation weighting simple random nonresponse