Statistics terminology

Terminology

individual:         The item under study (object, person, etc)
variable:           Characteristic of individual being studied

# types of populations
population:               A group of `individuals` that all share a theme. (ex. subset of individuals that live in urban areas)
sample:                   A small portion of a `population` (ex. subset of individuals that live in urban areas, between 30-40)

# study types
census:                   A study that includes data from all individuals in a population (rather than a sample)
#??                       A study that includes data from a sample of a population

parameter:                A measure describing the entire population
statistic:                A measure describing a sample of population

descriptive stats:        Organize/Picture/Summarize info from a population or sample
inferred stats:           Using info from a `sample` to inform a stat

quantitative/continuous:  A numeric measure (can calculate mean) (ex. temp)
qualitative/categorical:  A quality (cannot calculate mean) (ex. gender, country)

interval:                 A `quantitative` datatype where a 0 value is *NOT* possible (ex. time)
ratio:                    A `quantitative` datatype where a 0 value *IS* possible (ex. blood pressure)

nominal:                  A `qualitative` datatype that can be categorized, but not ranked (ex. gender, country-of-birth)
ordinal:                  A `qualitative` datatype that can be categorized and ranked (ex. coding-profficiency, stage of cancer)

class:                    An interval in data (ex. between 20-29)
class-limit:              Lowest/Highest number within class (ex. 20 and 29)
class-width:              Number of distinct possible values within class 29-20==9

Statistical Notation

N:  Total population
n:  Sample of population