Essential Statistics and Probability Terms Defined

Descriptive Statistics

Classification and description of a dataset.

Statistical Inference

Interpreting results using descriptive techniques for decision-making.

Statistic

A numerical summary or descriptive feature of a total sample of research.

Frequency Polygon

A line graph usually plotted on a frequency histogram.

Experiment

A controlled procedure carried out to determine, demonstrate, or test a hypothesis; a process that yields an outcome.

Median

The midpoint of a data set.

Probability

Measures or quantitatively determines the possibility that an event occurs.

Objective Probability

Probability obtained through numerical calculations or empirical observations.

Classic Approach

Assumes that all events are equally likely to occur.

Event

A possible outcome or group of possible outcomes of an experiment or observed process.

Simple Event

A single possible outcome in a sample space.

Dependent Events

Events in which the occurrence of one event affects the occurrence of another.

Independent Events

Events in which the occurrence of one does not affect the occurrence of another.

Probability Tree

A graphical representation showing the possible outcomes of a series of experiments and their respective probabilities.

Complement of an Event

The elements of the sample space not included in the event considered.

Statistical Dependence

A condition where the probability of an event depends on, or is affected by, the occurrence of some other event.

Venn Diagram

A graphical representation of probability concepts where the sample space is represented by a rectangle, and events within the sample space are represented as parts of that rectangle.

Sample Space

The set of all possible outcomes of a randomized trial.

Randomized Experiment

An experiment or trial with two or more possible outcomes, where the specific outcome cannot be anticipated, often involving random processes.

Relative Frequency of Presentation

The fraction of times an event occurs under stable conditions, or the observed relative frequency of an event over a very large number of trials or experiments.

Statistical Independence

A condition where the occurrence of one event has no effect on the probability of another event.

Joint Probability

The probability that two or more events occur simultaneously or in succession.

Output Probabilities

The probability of the intersection of two or more events.

Sum of Probabilities

The probability of the union of two or more events.