Sampling Methods and Statistical Inference Principles

Inference

Interpretation of results based on evidence.

Causality

Ability to show that variable B caused a change in variable A.

Scope

Generalizability of results to units outside the study.

Simple Random Sampling

Each element in the population has an equal chance of being selected.

Stratified Sampling

Population divided into groups (strata) for sampling.

Systematic Sampling

Samples selected at regular intervals throughout the study area.

Cluster Sampling

Population divided into clusters, and a random sample of clusters is taken.

SRS

Every possible sample unit in the study area has an equal chance of being sampled.

Randomization

Process of ensuring a random selection of samples.

Strata

Groups into which a population is divided for sampling.

Plots (quadrats)

Small geographic areas used to sample habitat characteristics or count animals.

Points (point counts)

Measurements taken from established points throughout a target population.

Transects (distance sampling)

Straight-line segments used for sampling, often combined with point or plot sampling.

Individual organisms

Organisms serving as the sample unit or defining the location of the sample unit.