This document discusses variables, scales of measurement, and related terminology in statistics. It defines a variable as any characteristic that differs between individuals, time, or place. Variables can be either qualitative (categorical) or quantitative (numerical) in nature. Quantitative variables are further divided into discrete variables, which have no gaps between values, and continuous variables, which have decimals. Scales of measurement include nominal, ordinal, interval, and ratio scales. The document also defines key terms like population, sample, parameter, statistic, and provides examples of variable types.

1. Variables and Scales of
Measurement

2. Variables
• Variable is any characteristic that differs
between individuals, Time or place.
• Example of Variables:
• (1) No. of patients (2) Height
• (3) Sex (4) Educational Level

3. Types of variables
1. Quantitative/Numerical Variable: is a
characteristic that can be measured in
numbers.
Examples:
(i) Family Size (ii) No. of patients
(iii) Weight (iv) height (v) Age

4. Types of Quantitative Variable
a)Discrete Variables: There are no gaps or
decimals between the values.
•Examples:
•- Family size (x = 1, 2, 3, … )
•- Number of patients (x = 0, 1, 2, 3, … )
•(b) Continuous Variables: There are
gaps/decimals between the values.
•Examples: - Height (140 < x < 190)
•- Blood sugar level (10 < x < 15)

5. 2. Qualitative/Categorical Variable: is a
characteristic that its values can be divided into
categories.
Example:-
i) Blood type ii) Nationality
iii) Students Grades iv) Educational level
• All qualitative variables are desecrate.

6. Discrete
(whole
number)
Qualitative Quantitative
Discrete
(whole
number)
Continuous
(Decimal)
Variable
Type:
Nature:

7. Scales of Measurements
• Nominal Scale: implies name only no order or rank is involved.
E.g. Sex, blood type, institutional departments, nationality.
• Ordinal Scale: implies name and order or rank. E.g. Educational
Level, military rank, students’ grades.
• Interval Scale:0 does not imply absence of the characteristics.
Interval between two numbers – meaningful
Ratio between two numbers not meaningful.
E.g. Temperature
• Ratio: 0 imply absence of the characteristics
both Interval and Ratio between two numbers – are
meaningful
eg. Height, Weight, age, income

8. Qualitative Quantitative
Variable
Interval Ratio
Type:
Scale: Ordinal
Nominal

9. Pre-request terminologies
• Data: is the raw material of statistics.
• Population (N): is the largest collection of
entities (elements or individuals) in which we
are interested at a particular time and about
which we want to draw some conclusions. E.g.
all HIU students.
• Sample: subset of the population.
• Sample size (n): : No. of individuals or
elements in the sample. E.g. 50 HIU students

10. • Parameter: is summaries computed from
population. E.g. mean age of entire HIU
students
• Statistic: is summaries computed from
sample. E.g. mean of 50 HIU students

11. Variable name Var type (Qn/Ql) Var nature (D/C) Scale (N/O/I/R)
Occupation
Religion
Hours of study
Parity
Shirt collar size
Sample size
Blood group
Exam score
Serum creatinine level
Duration of hospital stay
Eye colour
Eye Vision
Liver size
Education
Practical Exercise