probability
calculation tool
statistics
observation of past
sample space
all possible outcomes
event
a specific possible outcome
discrete
finite
continuous
changing
frequentist
measure of occurrences
subjective
measure one's belief
random sample
any possible outcome
population
collection to be analyzed
experiment
planned activity that yields data
parameter
number that describes a population
statistic
number computed from sample
statistic variable
measurable characteristic
statistical model
an equation that shows relationship of variables
statistical inference
using sample information to learn about population
Descriptive Statistics
statistics dealing with organizing and summarizing data
Inferential Statistics
making predictions about unknown population parameters using sample statistics
Constant
do not change in repeated trials over time
Variable
measurements of some characteristic vary from trial to trial
Qualitative
Measurements vary in kind or name but not in degree meaning they cannot be ranked
Quantitative
measurable data that is discrete or continuous
nominal
named
ordinal
ordered
bias
some individuals are systematically favored over others
Simple random sampling
list of all possible individuals in the population is made and n subjects are chosen in such a way that every set of n subjects has an equal chance of being selected
Stratified random sampling
population is naturally divided into two or more groups of similar subjects called strata
Multistage random sampling
The population is divided into several clusters and these are further divided into smaller sub-clusters
Haphazard sampling
This method involves selecting a sample by some convenient mechanism that does not involve randomization
Volunteer Response Sampling
people volunteer to be a part of the study. EX- telephone call in polls ,internet survey
Factor
explanatory variables that cause a change in the response
Levels
specific value of factor
Double-blinding experiment
In addition to the experimental units, those people who are conducting the experiments not know to which group the experimental units have been assigned
Confounding experiment
The existence of some factor other than the treatment that makes treatment and control groups different
Observational study
No treatment is imposed (shows association not causation)
Block
group of individuals that are known before the experiment to be similar in some way that is expected to affect the response to the treatments