Statistics Lecture 1 Flashcards
Statistics
The science of assembling, classifying, tabulating, and analyzing data of a numerical nature to present significant information about a given subject.
Main branches of statistics
- Descriptive statistics
- Inferential statistics
Descriptive statistics
a way of summarizing data from a population or a sample.
Inferential statistics
Comparison of data, extrapolation…
Data
A collection of information. A set of values of qualitative or quantitative variables.
Types of data
- Qualitative
- Quantative
Quantitative data
Numeric date
Qualitative data
Non-numeric date
Observation
Entity whose characteristics we measure
Measurement
Assigning numbers to observations according to pre-set rules
Variable
A measurement characteristic that can have various values or levels
Types of variables
- Qualitative(categorical) = Non numerical
- Quantitative = Numerical
Types of quantitative variables
- Discrete
- Continuos
Types of qualitative variables
- Binary
- Nominal
- Ordinal
Continuos:
- Quantitative
- Not restricted to taking specified values
Discrete:
- Quantitative
- Can have only certain values (usually whole numbers)
Binary:
Only 2 possible values (usually : 1/0 or Yes/No
Nominal:
- Qualitative
- Categorical with no order
Ordinal:
- Qualitative
- Non numerical but with a specific order
Population
is an entire group of observations that have at least one common characteristic
- Monkey Population St. Kitts
- Female monkey population in St. Kitts
- Monkeys in a research facility
Sample
is a group of elements selected from a population
A characteristic of a population
Parameter
Characteristic of a sample
Statistic
Absolute frequency
Number of observations
Relative frequency
Proportion of observations
