2. Objectives
•Define universe and differentiate it with
population; and
•Define and differentiate between qualitative
and quantitative variables, and between
discrete and continuous variables (that are
quantitative);
3. Definition of BasicTERMS
UNIVERSE (of the study) - The collection of
respondents from whom one obtain the data
What is the UNIVERSE of the study in our past
activity?
4. Variables
•is a characteristic that is observable or
measurable in every unit of the universe.
What are the variables in the activity?
5. POPULATION
•the entire set of items from which you
draw data for a statistical study
•any complete group with at least one
characteristic in common
6. SAMPLE
•A subgroup of a universe or of a
population
•Smaller and more manageable
representation of a larger group
•Unbiased subset of a population that best
represents the whole data.
7. Population parameter vs. sample
statistics
•Population parameter is a numerical value that
describes a characteristics of a population while
sample statistics is a numerical value that
describes a characteristics of a sample
•MEAN vs SAMPLE MEAN
•SD vs Sample SD
10. Qualitative variable
•Express a categorical attribute
•Not strictly take on numerical values
•Answers the questionWHAT KIND?
•Sometimes it considers the sense of
ordering
•Also known as categorical variables
16. Keypoints
•A universe is a collection of units from which the data were
gathered.
•A variable is a characteristic we observed or measured from
every element of the universe.
•A population is a set of all possible values of a variable.
•A sample is a subgroup of a universe or a population.
•In a study there is only one universe but could have several
populations.
•Variables could be classified as qualitative or quantitative, and
the latter could be further classified as discrete or continuous.
