Introduction (1.1) Data - Information collected by individuals and/or organizations to gain knowledge regarding a field or question of interest. Data Sources: Surveys (Mail, Telephone, Internet) Content Analysis (Newspaper, Magazine, Television) Natural Experiments/Field Studies Controlled Experiments Statistics- Set of methods for collecting/analyzing data

Uses of Statistical Methods (1.1) Design - Planning/Implementing a study Constructing a survey and deciding who to sample Determining methods to be compared Deciding which groups of units to be analyzed Description - Summarizing data Typical outcomes and distributions of outcomes Tables and/or Graphs Inference - Using sample data to predict or make statements regarding unobserved data

Description and Inference (1.2) Population - Full set of subjects of interest to researcher Sample - Subset of population that is observed and measured in a data collection study Descriptive Statistics - Summary of the information in a sample of data Inferential Statistics - Statements regarding a population, based on a sample

Parameters and Statistics (1.2) Parameter - Numeric summary of a population Population Mean - Average of a numeric measure Population Proportion - Fraction having a particular characteristic Statistic - Numeric summary of a sample Populations can be well defined or conceptual Inferences depend on the sample being representative of the general population

Statistical Computing (1.3) Statistical computer packages have become widespread over recent years, and their methods and ease of use have improved drastically in recent years (SPSS, SAS, Minitab, STATA, etc) Data must be entered into a data file: Rows typically represent individuals Columns typically represent variables