Chapter 1 Vocabulary
Data are collections of observations (such as measurements, genders, survey
responses).
Statistics is the science of planning studies and experiments, obtaining data, and
then organizing, summarizing, presenting, analyzing, interpreting, and drawing
conclusions based on the data.
A population is the complete collection of all individuals (scores, people,
measurements, and so on) to be studied. The collection is complete in the sense
that it includes all of the individuals to be studied.
A census is the collection of data from every member of the population.
A sample is a subcollection of members selected from a population.
A parameter is a numerical measurement describing some characteristic of a
population.
A statistic is a numerical measurement describing some characteristic of a sample.
Quantitave (or numerical ) data consist of numbers representing counts or
measurements.
Categorical (or qualitative or attribute) data consists of names or labels that are not
numbers representing counts or measurements.
Discrete data result when the number of possible values is either a finite number or
a “countable” number. (That is, the number of possible values is 0 or 1 or 2, and so
on.)
Continuous (numerical) data result from infinitely many possible values that
correspond to some continuous scale that covers a range of values without gaps,
interruptions, or jumps.
The nominal level of measurement is characterized by data that consist of names,
labels, or catagories only. The data cannot be arranged in an ordering scheme
(such as low to high).
Data are at the ordinal level of measurement if they can be arranged in some order,
but differences (obtained by subtraction) between data values either cannot be
determined or are meaningless.
The interval level of measurement is like the ordinal level, with the addition
property that the difference between any two data values is meaningful. However,
data at this level do not have a natural zero starting point (where none of the
quantity is present).
