sampling Statistics 33 regression 21 probability 20 correlation 7 normal distribution 4 binominal distribution 3 frequency distribution 3 dispersion 2 non parametrics 2 non-parametric 2 variance 2 Basic statistics 1 Biological monitoring 1 Ecology 1 Quantitative data 1 Research design 1 Scientific methods 1 Social scienc -statistical management 1 Statistical survey 1 Stream ecology 1 Water quality biological assessment 1 central value 1 chemical analysis 1 computer sciences 1 data collection 1 education 1 elementary probability 1 emerging pest problems 1 estimation 1