Statistics: refers to a set of mathematical procedures for organizing, summarizing and interpreting information: informative and time saving; condenses a large quantity of information into a few figures. Statistical procedures help ensure the information/observations are presented and interpreted in an accurate and informative way: provides a set of standardized techniques that are recognized and understood by the scientific community. Population: the set of all individuals of interest in a particular study: can vary in size extremely large or small; depends on how the researcher defines it. Sample: a set of individuals selected from a population, usually intended to represent the population in a research study: goal is to generalize the results back to the entire population. Variable: a characteristic/condition that changes/have different values for different individuals. Data: measurements/observations: data set: a collection of measurements/observations, datum: a single measurement/observation (also called score/raw score) Parameter: a (numerical) value that describes a population, usually derived from measurements of the individuals in the population.