Week 1: Basic Concepts Flashcards
Type of variables
1) qualitative or categorial and 2) quantitative
Types of qualitative variables
1) Ordinal or ordered
2) Nominal or unordered
Example of ordinal variables
Hot hotter hottest
Example of nominal or unordered variables
Red, green, yellow
Type of quantitative variables
1) Discrete and 2) continuous
Discrete variables
Values are whole numbers
Continuous variables
May contain decimals
Statistical variable
Observed characteristic or measurement
Statistical unit
Unit observation for which data are collected
Population
The whole set of statistical units
Random sample
The subset of statistical units selected from the population in a suitable way
Sample size
Total number of sample units
Random sample is used to
Avoid non representative samples of the population
First step of statistical analysis
Descriptive analysis
Descriptive analysis
Summarizes and visualizes the main features of the sample data
Descriptive analysis
Summarizes and visualizes the main features of the sample data
Second step of statistical analysis
inferential analysis
Descriptive analysis of sample data
1) frequency distributions
2) study of the shape data
3) measures of central tendency
4) measures of variability
What do we do with inferential analysis?
We generalize findings from samples to populations to estimate population values, make comparisons and asses relationship between variables
Inferential analysis can be
1) point estimates and confidence intervals
2) hypothesis testing
3) regression models
4) analysis of variance
