3. BIO - STATISTICS
Two words bio and statistics
1. Bio :
that relating to biological
problems or living organisms
2. Statistics :
data gathering
4. BIOSTATISTICS
• DEFINITION
Statistical processes and methods applied to the
collection, analysis, and interpretation of
biological data and especially data relating to
human biology, health, and medicine
5. VARIABLES
• A variable is a factor that can
take different values for
individuals in a study
• Variable is something that we
can measure as well as
manipulate
• Experimental or non-
experimental studies
• Dependent and independent
variable
9. TYPES OF VARIABLE
1. Variable may Qualitative (Categorical – Describe attribute)
• Binary
• Nominal
• Ordinal
2. Variables may Quantitative (Numerical values)
• Continuous Data
• Discrete Data
10. QUALITATIVE = CATEGORICAL VARIABLE
1. Binary:
Allocation of observations to one of only two possible
categories.
Example, Gender m/f , yes/no, True/False
11. QUALITATIVE = CATEGORICAL VARIABLE
2. Nominal:
• Allocation of observations into
more than two categories.
• The data cant be ranked or
grouped in any order at all
• Example, Brown Black Red
Silver Yellow
12. QUALITATIVE = CATEGORICAL VARIABLE
3. Ordinal:
Allocation of observations into more
than two categories that can be
ordered.
Example
Unhappy - Ok Happy - Very Happy
Anxious - Not anxious - Very anxious –
Extremely
anxious
13.
14. QUANTITATIVE = NUMERICAL VARIABLES
1. Continuous Data: A set of data is said to be continuous
if the values are measurements that can assume any
value within a specified range.
Example: Temperature ,Height, Weight
15. QUALITATIVE = CATEGORICAL VARIABLE
2. Discrete Data: A set of data is said to be discrete if the
values are distinct and separate. That is, they can be
counted (1,2,3, ...).
Example : Number of new TB cases in a month /
Number of patients in a clinic
16. DATA
• Data is a set of values of qualitative or quantitative
variables.
• Facts or figures to be processed; evidence, records,
statistics, etc. from which conclusions can be inferred
17.
18.
19. 1- QUANTITIVE OR (NUMERICAL DATA).
Data which can be measured with a scale or
which gives numeric values
Example;
1. Age
2. weight & Hight
3. Temperature
4. Blood pressure
5. How many pages you can read of your
favorite book before you fall asleep
20. 2-QUALITATIVE OR CATEGORICAL DATA
Data which can be counted or which has
different categories
Example;
1. Gender
2. Blood Group
3. Marital Status
4. Hometown
5. Types of Movies they Like
21. CLASSIFICATION OF DATA
• Data can classified in number of ways, one is as
described above Qualitative & Quantitative
• Others types are;
1. Nominal Data
2. Ordinal Data
3. Interval
4. Ratio
22. NOMINAL DATA
• This type of data is in the form of names, labels or
categories.
• It cannot be ranked or grouped in any order.
• Nominal is the lowest level. Only names are
meaningful here.
Example; Gender , Race, Type of teeth ect
23. ORDINAL DATA
• Ordinal adds an order to the name
Example
• Large, Medium, Small
• Good, Bad, Malnourished
• Normal , Overweight, Obese,
• Decayed , Missing , Filled
24. INTERVAL DATA
• Interval data is a type of data which is measured
along a scale, in which each point is placed at an
equal distance (interval) from one another.
• Examples;
1. Temperature
2. Time
3. IQ
25. INTERVAL DATA
1. Temperature
An example of interval data is the
data collected on a thermometer—
its gradation or markings are
equidistant.
26. INTERVAL DATA
2. Time
• Time passes as a good example of interval
data if measured during the day or using a
12-hour clock. The numbers on a wall clock
are on an interval scale since they are
equidistant and measurable.
• For example, the difference between 1
o’clock and 2 o’clock is the same as that
between 2 o’clock and 3 o’clock.
27. INTERVAL DATA
3. IQ Test
• According to psychological
studies, one can not have zero
IQ. Also, IQ is determined using
a fixed measurement scale.
Therefore, IQ is an example of
interval data.
28. RATIO DATA
Similar to interval but ratio has a true
ZERO or starting point
Example;
Hight, Weight, Length, distance,
traveled
Each point value can be expressed as
meaningful ratio to another e.g twice
the weight
29. EXAMPLES
What is your weight in kgs?
• Less than 50 kgs
• 51-60 kgs
• 61-70 kgs
• 71-80 kgs
• 81-90 kgs
• Above 90 Kgs
What is your height in feet
and inches?
• Less than 5 feet.
• 5 feet 1 inch – 5 feet 5
inches
• 5 feet 6 inches- 6 feet
• More than 6 feet
What is the number of
burgers you can eat daily?
• 1-2
• 2-3
• 3-4
• 4-5
• 5-6
• More than 6
