Stat 114: Introduction to Statistics

Statistics - branch of science that deals with the collection, organization, analysis, interpretation, and presentation of data.
Statistical inquiry - designed research providing information needed to solve a research problem.
Information - processed data.
Population - collection of all elements under a statistical inquiry.
Sample - subset of the population.
Elements - units whose characteristics will be observed & measured to answer research problem.
Variable - characteristic/attribute of elements in a collection that can assume diff. Values for diff. elements.
Observation - realized value of a variable measured from an experiment.
Data - collection of observations.
Summary measure - single numeric figure that describes a particular feature of the whole collection.
- Parameter - describes specific characteristic of a population
- Statistic - describes specific characteristic of a sample

Applied statistics - procedures & techniques used in the collection, organization, analysis, interpretation, and presentation of data.
- Select & implement proper statistical methods
  - Descriptive Statistics - techniques used for data on hand; cannot make generalizations if data on hand is sample data
  - Inferential Statistics - analyze sample data to make generalizations
    - Arrive at conclusions with uncertainty due to partial info only
    - Probability theory will help understand possible errors
Theoretical/mathematical statistics - development of mathematical foundations used in applied statistics
- Rationale behind methods used; establish new theories that will validate the use of new stat methods/modify existing methods

Objectives of Doing a Statistical Inquiry: (DDDCCPRIF)

Describe characteristics of population through parameter estimation/computation
Compare characteristics of elements in different subgroups through contrast
Justify assertion made by researcher about population characteristic
Determine nature/strength of relationships among the diff. values of interest
Identify diff. groups of interrelated variables under study
Reveal the natural groupings of elements in the population based on the values of a set of variables
Determine effects of one or more variables on a response variable
Clarify patterns & trends in the values of a variable over time/space
Predict the value of a variable based on its relationship with another variable
Forecast future values of a variable

Stages in Doing a Statistical Inquiry: