HW: Read article at http://abcnews.go.com/Technology/story?id=6034371&page=1#.T-NzPfWlidw8/20


Chapter P – Key Concepts

Statistics – the science and art of collecting, organizing, describing, and drawing conclusions from data. Involves data production, data analysis, probability, and statistical inference

Data- numbers within a context (100 does not mean anything until you put the “$” in front of it)

Data production- helps answer specific questions with an experiment or observational study

Population – a large group

Sample- a smaller, subgroup that represents the population

Probability – the study of chance behavior, tells you how likely or unlikely an event is to occur. Chance behavior is unpredictable in the short run by has a regular and predictable pattern in the long run

Available data – data that was produced in the past for some other purpose but that may be helpful to answer a present question

Survey- a popular way to gauge public opinion

Observational study – observe individuals and measure variables of interest but do not attempt to influence the responses

Experiment – deliberately do something to individuals in order to observe their responses

Data analysis – organizing, displaying, summarizing, and asking questions about the data

Individuals- the objects described by a set of data. Individuals may be people, animals, or things

Variable-any characteristic of an individual

Categorical variable- places an individual into one several groups or categories (gender, grade level)

Quantitative variable – takes numerical values for which arithmetic operations such as adding and averaging make sense (SAT score, salary)

Distribution – tells us what values the variable takes and how often it takes these values

*Many relationships between two variables are influenced by other variables lurking in the background

Exploratory data analysis- uses graphs and numerical summarizes to describe the variables in a data set and the relationships among them. May not be generalizable beyond the specific data studied

Statistical inference- produces answers to specific questions, along with a statement of how confident we can be that the answer is correct. Usually intended to apply beyond the individuals specifically studied.