DEMOGRAPHY

DEMOGRAPHY
DR. MAHESWARI JAIKUMAR.
maheswarijaikumar2103@gmail.com

ETYMOLOGY
• 1. DEMOS - People.
• 2. GRAPHO - To write.
• The word was coined by JOHN
GRUNT

DEFINITION
• Demography is the "study of
human populations in relation to
the changes brought about by the
interplay of births, deaths, and
migration" PRESSAT

DEFINITION
• "Demography is the statistical
description and analysis of
human population". - WRONG

• Demography is the "statistical and
mathematical study of the size,
composition and spatial
distribution of human populations,
and of the changes over time, in
these aspects through the
operation of the five processess of
fertility, mortality, marriage,
migration and social mobility" -
BOGUE

CONCEPT & SCOPE
• Demography is the branch of
social size, structure, which deals
with the study of size, structure
and distribution of populations,
along with the spatial and temporal
changes in them in response to
birth, migration, ageing and death.

DEMOGRAPHIC INDICATORS :
(Eg)
• Crude Birth Rate. (CBR)
• General Fertitlity Rate. (GFR)
• Crude Death Rate. (CDR)
• Infant Mortality Rate. (IMR)

• Life expectancy. (LE)
• Total Fertility Rate. (TFR)
• Gross Reproduction Rate.(GRR)
• Net Reproduction Rate. (NRR)

SCOPE OF DEMOGRAPHY
• Demography is the science of
population. In it's most general
meaning, a population is a set of
people who live in a specific land
area : a commune, a district, a
country or a continent,etc.
• A formal demography is concerned
with the size, distribution, structure
and changes of population

SIZE
• Is the number of units (inhabitants)
in the population

DISTRIBUTION
• Is the arrangement of the
population at a given time,
geographically or among various
types of residential areas.

STUCTURE
• Is the distribution of characteristics
such as age, gender groups etc
among the population.
• Additional characteristics of the
uinits such as marital status,
occupation educational level, ethnic
characteristics, socio economic
status etc.

CHANGE
• Is the increase or decrease of
the total population or of the
one of it's structural units.

NARROW SCOPE
• Population is constantly
changing over time.
• The components of change in a
population are births, deaths
and migration.

• Thus one generation will be
replaced by another younger
generation by birth and death
process.
• This is a natural change or
demographic reproduction.

BROADER SCOPE
• The broader scope of
demographic reproduction
includes migration. It means
the movement of people from
place to place.
• Migration has great influence
on population change.

• Within a country or an area, this
movement does not affect the total
size of the population.
• It changes the structure of the
population and area as well as the
living conditions of immigrants and
out-migrants.

• This process may also influence
the behaviour of the inhabitants,
especially out migrants.
• Migrations have great influence on
population change.

• A balancing equation of population
change in time that involves the
relationship between birth, death
and migration is as follows.
• P1 = P0 + (B - D) + (I - O):
• where, P1 & P0 : Population at the
ending & begening point.
• B = # of Births in a period.
• D = # of Deaths in a period.
• I = # of In - migrants.
• O = # 0f Out - migrants

DEMOGRAPHIC CYCLE
• Demography cycle has five stages:
• HIGH STATIONARY.
• EARLY EXPANDING.
• LATE EXPANDING.
• LOW STATIONARY.
• DECLINING.

DEMOGRAPHY CYCLE
DEMOGRAPHY
CYCLE
HIGH STATIONARY.
EARLY EXPANDING.
LATE EXPANDING.
LOW STATIONARY.
DECLINING.

DEMOGRAPHY CYCLE
HIGH STATIONARY.
EARLY EXPANDING.
LATE EXPANDING.
LOW STATIONARY.
DECLINING.
High Birth Rate
High Death Rate
Unchanged Birth Rate
Decline Death Rate
Fall in Birth Rate
Death Rate further
Low Birth Rate
Low Death Rate
Birth rate lower than
Death Rate

STAGES OF DEMOGRAPHY
CYCLE & COUNTRIES
High Stationary High High India (1920)
Early Expanding Unchanged Decline
South Asia,
Africa
Late Expanding Fall
Further
Decline
China,
Singapore, India
Low Stationary Low Low
Austria (1980-
1985)
Declining Further lowers Unchanged
Germany,
Hungary
STAGE BIRTH RATE DEATH RATE COUNTRIES

DEMOGRAPHIC INDICATORS
• 1. Measurement of Mortality.
• 2. Measurement of Morbidity.
• 3. Measurement of disability.
• 4. Measurement of natality.
• 5. Measurement of the presence,
absence or distribution of the
characteristics or attributes of the
disease.

• 6. Measurement of medical needs,
health care facilities, utilization of
health services and other health
related events.
• 7. Measurement of the presence,
absence or distributionof the
environmental and other factors
suspected of causing the disease.

• 8. Measurement of demographic
variables.

TOOLS OF MEASUREMENT
• An epidemiologist usually
expresses the health event as
RATES, RATIOS or PROPOTION.

RATE
• A rate measures the occurence
of some particular event in a
population during a given
period of time period.
• It is the statement of the risk of
of developing a condition.

• It indicates the change in some event
that takes place in a population over a
period of time.
•
X 1000
DEATH RATE = NUMBER OF DEATHS
MID YEAR POP
X 1000

RATE : EXAMPLE
Weekly death rate = Deaths in a week x 52
Mid year population
x 1000

• A rate comprises the following
elements.
• 1. Numerator.
• 2. Denominator.
• 3. Multiplier.

The time dimension is usually a
calender year.
The rate is expresses per 1000 or
some round figure.(selected
according to convenience or
convention to avoid fraction).

RATIO
• Ratio expresses a relation in
size between two random
quantities.
E.g., x : y (or) x/y.

• The numerator is not a component
of the denominator.
• The numerator and denominator
may involve an interval of time or
may be simultaneous in time.
The number of children with scabies at a
certain time.
The number of children with malnutrition
at a certain time

PROPORTION
• A Proportion is a ratio which
indicates the relation in magnitude
of a part of the whole.
• The numerator is always included
in the denominator.
• A Proportion is usually expressed
as percentage.

Example
The number of children with
scabies at a certain time.
The total number of children in
the village at the same time
x 100

MEASUREMENTS OF
MORTALITY
• Mortality refers to the number of
deaths in a given time or a place or
a proportion odf deaths in relation
to a population.
• E.g., : 1. Crude Death Rate.
2. Infant Mortality Rate.
3. Maternal Mortality Rate
4. Life Expectancy.

MEASUREMENTS OF
MORBIDITY
• It refers to diseases and illness,
injuries and disabilities in a
population.
• Data on the frequency and
distribution of a disease helps in
controlling its spread, and in some
cases it may lead to the
identification of cases.

Example
• 1. Case Rate : The case rate is
the number of reported cases
of a specific disease or illness
per 100,000 population during a
given year.

• 2. Case Fatality Rate : The Case
Fatality Rate is the proportion
of persons contacting a
disease who die of that disease
during a specified time period.

MEASUREMENT OF
DISABILITY
• Dependancy Ratio : The ratio of the
economically dependent part of the
population to the productive part;
arbitrarily defined as the ratio of
the elderly ( ages 65 and older)
plus the young (under age 15) to
the population in the "working
ages".

MEASUREMENTS OF
NATALITY
• Natality in population ecology is
the scientific term for Birth Rate.
• Along with mortality rate, natality
rate is used to calculate the
dynamics of a population.

• They are the key factors in
determining whether a population
is increasing, decreasing or
staying the same in size.
• Natality is the greatest influence on
a population’s increase.

• Natality is shown as a crude birth rate
or specific birth rate. Crude Birth Rate
is used when calculating population
size (number of births per 1000
population/year).
• whereas Specific Birth Rate is used
relative to a specific criterion such as
age. By calculating specific birth rate,
the results are seen in an age-specific
schedule of births.

BIRTH RATE (BR)
NUMBER IF LIVE BIRTHS DURING
THE YEAR.
ESTIMATED MID YEAR
POPULATION
X 1000BIRTH RATE =

GENERAL FERTILITY
RATE (GFR)
NUMBER OF LIVE BIRTHS
DURING A YEAR.
MID YEAR FEMALE POP (15-49)
IN THE SAME YEAR
X 1000GFR =

GENERAL MARITAL
FERTILITY RATE (GMFR)
DURING A YEAR.
MID YEAR MARRIED FEMALE
POP (15-49) YRS
GMFR = X 1000

AGE SPECIFIC FERTILITY
RATE (ASFR)
NUMBER OF LIVE BIRTHS IN A
PARTICULAR AGE GROUP.
MID YEAR POP OF THE
SAME AGE GROUP
ASFR = X 1000

AGE SPECIFIC MARITAL
FERTILITY RATE (ASMFR)
NUMBER OF LIVE BIRTHS IN A
PARTICULAR AGE GROUP.
MID YAER POP OF THE SAME AGE
GROUP.
ASMFR = X 1000

TOTAL FERTILITY RATE
(TFR)
• It is the average number of children
a women can give birth throughout
the reproductive period.
• It is represented by summing the
age specific fertility rates for all
ages; if 5 - year age groups are
used, the sum of the rates is
multiplied by 5.

TFR
45 - 49
15 - 19
1000
TFR =
5 X ASFR∑

TOTAL MARITAL
FERTILITY RATE (TMFR)
Average number of children
that would be born to a married
women if she experiences the
current fertility pattern through
her reproductive span.

TMFR
45 - 49
15 -19
1000
5 X ∑ ASMFRTMFR =

GROSS REPRODUCTION
RATE (GFR)
• Average number of girls that would
be borne to a women if she
experiences the curent fertility
pattern throught her reproductive
span (15 - 49 years) having no
mortality.

NET REPRODUCTIVE
RATE (NRR)
• NRR is defined as the number of
daughters a new borne girl will
bear during her lifetime assuming
fixed age-specific fertility and
mortality rates.
• At presesnt in India NRR is about
1.5

• If NRR is < 1, then the reproductive
performance of the population is
said to be below replacement level.

MARRIAGE RATES
• The marriage rate (CRUDE
MARRIAGE RATE) is the
number of marriages per 1000
total population in a given year.

MARRIAGE RATE
NUMBER OF MARRIAGES IN
THE YEAR
MID YEAR POPULATION
MR = X 1000

CHILD WOMAN RATIO
• Is the number of children 0 - 4
yrs of age per 1000 women of
child bearing age.

PREGNANCY RATE.
• It is the ratio of number of
pregnancies in a year to married
women in the ages 15-49 yrs.
• The "number of pregnancies"
includes all pregnancies, whether
or had terminated as live births,
stillbirths or abortions or had not
yet terminated.

ABORTION RATE
• The annual number of all types
of abortions, usually per 1000
women of child bearing age
(15-19 yrs).

ABORTION RATIO
• This is calculated by dividing
the number of abortions
performed during a particular
time period by the number of
live births over the same
period.

CRUDE DEATH RATE
(CDR)
NUMBER OF DEATHS DURING A
YEAR
MID YEAR POPULATION
CDR = X 1000

SPECIFIC DEATH RATE
NUMBER OF DEATHS FROM TB DURING A
CALENDER YEAR.
MID YEAR POPULATION
SDR = X 1000

SPECIFIC DEATH RATE IN
AGE GROUP 15-20 YRS
NUMBER OF DEATHS OF
PERSONS AGED 15-20
DURING A CALENDER
YEAR.
MID YEAR POPULATION OF
PERSONS AGED 15-20
SPECIFIC DEATH
RATE (15-20 YRS) = X 1000

DEATH RATE FOR
JANUARY
DEATHS IN
JANUARY X 12
MID YEAR
POPULATION
DEATH RATE
FOR JAN =
X 1000

WEEKLY DEATH RATE
DEATHS IN THE WEEK
MID YEAR POPULATION
WEEKLY
DEATH RATE = X 1000

CASE FATALITY RATIO
TOTAL NUMBER OF
DEATHS DUE TO A
PARTICULAR DISEASE
TOTAL NUMBER OF
CASES DUE TO THE
SAME DISEASE
X 100CFR =

PROPORTIONAL
MORTALITY RATIO
NUMBER OF DEATHS
FROM THE SPECIFIC
DISEASE IN A YEAR
TOTAL DEATHS FROM
ALL CAUSES IN THAT
YEAR
X 100PMR =

SURVIVAL RATE
TOTAL NUMBER OF PATIENTS
ALIVE AFTER 5 YEARS
TOTAL NUMBER OF PATIENTS
DIAGNOSED OR TREATED
SURVIVAL
RATE = X 100

STANDARDIZED
MORTALITY RATIO
OBSERVED DEATHS
EXPECTED DEATHS
SMR = X 100

INFANT MORTALITY RATE
(IMR)
NUMBER OF DEATHS OF
CHILDREN LESS THAN 1
YEAR OF AGE IN A YEAR
IN THE SAME YEAR
X 1000IMR =

ATTACK RATE
NUMBER OF NEW CASES OF
A SPECIFIED DISEASE
DURING A SPECIFIED TIME
INTERVAL
TOTAL POPULATION AT RISK
DURING THE SAME
INTERVAL
X 100AR =

STILL BIRTH RATE (SBR)
FOETAL DEATHS WEIGHING
OVER 1000g AT BIRTH
DURING THE YEAR
TOTAL LIVE + STILL BIRTHS
WEIGHING OVER 1000g AT
BIRTH DURING THE YEAR
X 1000SBR =

PERINATAL MORTALITY
RATE (PMR)
LATE FOETAL AND EARLY
NEO NATAL DEATHS
WEIGHING OVER 1000g
AT BIRTH
TOTAL LIVE BIRTHS
WEIGHING OVER 1000g
AT BIRTH
X 1000PMR =

NEONATAL MORTALITY
RATE (NMR)
NUMBER OF DEATHS
OF CHILDREN
UNDER 28 DAYS OF
AGE IN A YEAR
TOTAL LIVE BIRTHS IN
THE SAME YEAR
X 1000NMR =

POST NEONATAL
MORTALITY RATE
NUMBER OF DEATHS OF
CHILDREN BETWEEN 28
DAYS AND ONE YEAR OF
AGE IN A GIVEN YEAR
TOTAL LIVE BIRTHS IN THE
SAME YEAR
X 1000PNMR =

CHILD DEATH RATE
NUMBER OF DEATHS OF
CHILDREN AGED 1-4
YEARS DURING A YEAR
TOTAL NUMBER OF
CHILDREN AGED 1-4
YEARS AT THE MIDDLE
OF THE YEAR
X 1000CDR =

CHILD MORTALITY RATE
NUMBER OF DEATHS OF
CHILDREN LESS THAN 5
YEARS OF AGE IN A
GIVEN YEAR
IN THE SAME YEAR
X 1000CMR =

CHILD SURVIVAL INDEX
1000 - UNDER 5
MORTALITY RATE
10

MATERNAL MORTALITY
RATIO
TOTAL NUMBER OF FEMALE DEATHS
DUE TO COMPLICATIONS OF
PREGNANCY, CHILDBIRTH OR
WITHIN 42 DAYS OF DELIVERY
FROM PUERPERAL CAUSES IN AN
AREA DURING A GIVEN YEAR
TOTAL NUMBER OF LIVE BIRTHS IN
THE SAME AREA AND YEAR
X 1000 /
100000MMR =

DISABILITY RATES
• INDICATORS USED TO MEASURE
DISABILITY :
1. SULLIVAN INDEX
2. HEALTH ADJUSTED LIFE
EXPECTANCY (HALE).
3. DISABILITY ADJUSTED LIFE
YEAR

SULLIVAN INDEX
LIFE EXPECTANCY - (PROBABLE DURATION
OF BED DISABILITY + INABILITY TO
PERFORM MAJOR ACTIVITIES)

HEALTH ADJUSTED LIFE
EXPECTANCY (HALE)
• Is an indicator of health which
measures healthy life expectancy.
• HALE is equivalent to the number
of years newborn child expected to
live with full health.

DISABILITY ADJUSTED LIFE
YEAR (DALE)
• Is used to express the years of life
lost to premature death and years
lived with disability for severity of
disability.
• ONE DALY = ONE LOST YEAR OF
HEALTHY LIFE

CASE RATE
Number of reported
cases of a specific
disease or illness
100,000 population
during a given year

EMIGRATION RATE
NUMBER OF EMIGRANTS
DEPARTING AN AREA OF
ORIGIN
1000 POPULATION AT THAT
AREA OF ORIGIN IN A GIVEN
YEAR

NET EMIGRATION RATE
The net effect of immigration and
emigration on an area's population
(increase or decrease) is refered to
as net migration.
The net migration shows the net
effect of immigration & emigration
on an area's population of the area
in a given year.

GROWTH RATE
The growth rate is the rate at which a
population is increasing (or
decreasing) in a given year due to
natural increase and net migration,
expressed as a percentage of the base
population.
• The growth rate takes in to account all
components of population growth:
births, deaths and migration.

LIFE EXPECTANCY
The number of years which an
individual at a given age could
expect to live, at present
mortality levels

USES OF DEMOGRAPHIC
DATA
• Analysis patterns and trends
related to human religion,
nationality, education and
ethnicity.
• Estimates are reliable standards
for judging the accuracy of the
census information gathered at
any time.

• Estimates size and flow of
populations of workers; in
population ecology, the focus is on
birth, death and movement of firms
and institutional forms.
• Uses administrative records to
develop an independent estimate
of the population.

• Provides insight into the links
between these characteristics and
cultural, economic, geographic and
other social attributes present in a
given area.
• Demographic analysis is a
powerful tool that can explain a
number of sociological
phenomena.

• Used to estabilish the percentage
of the total population involved in a
particular resource use activity,
such as fishing or tourism.
• Apply to whole societies or to
groups defined by criteria such as
education, nationality, religion and
ethnicity.

• Analyzes the relationship between
economic, social, cultural and
biological proceses influencing a
population.
• Time and age have special
relationships in popultion studies,
from which cross sectional and
cohort analysis are developed.

• Relates to whole societies or to a
smaller groups defined bycriteria
such as education, religion or
ethnicity.
• Develops targeted outreach and
training activities for local
communities.

HEALTH
INFORMATION
SYSTEM (HIS)

DEFINITION
• Heath Information or Medical
Statistics refers to any quantifyable
and non quantifiable information
that can be used by health decision
makers and clinicians to better
understand disease process and
health care issues, and to prevent,
diagnose or treat health problems.

• Medical statistics deals with the
application of bio statistics to
medicine and the health sciences,
including epidemiology, public
health, forensic medicine and
clinical research.

• A HIS system refers to inter
related component parts for
acquiring and analysing data and
providing information for the
management of a health
programme or system and for
monitoring health services

SOURCES OF HEALTH
INFORMATION
• The main population based
sources of health information are
as follows :
• 1. Census.
• 2. Household Surveys.
• 3. Sample Registration System.
• 4. Notification of Diseases'.
• 5. Hospital Records.

• 6. Disease Registers.
• 7. Record Linkage.
• 8. Epidemiological Surveillence.
• 9. Other Health Service Records.
• 10. Environmental Health Data.
• 11. Population Surveys.
• 12. Other routine statistics related
to health.
• 13. Non quantifiable information.

METHODS OF DATA
COLLECTION
• There are two methods of data
collection:
1. DIRECT METHOD.
2. INDIRECT METHOD.

DIRECT METHOD
1. VITAL STATISTICS REGISTRIES:
A. BIRTHS & DEATHS.
B. CENSUS.
C. LEGAL STATUS (Marriage,
divorce and migration)

CENSUS
• Census is taken typically every 10
yrs.
• Census are also used as direct
source of information about
fertility and mortality.

• The census is commonly
performed by a government
agency and the methodology used
is the individual or household
enumeration.
• In India the first census was taken
in the year 1901 on March 1st.
• The latest census was taken in the
year 2001 on March 1st.

The purposes for census include :
1. As a basis for taxation.
2. As a basis for political
representation.

INDIRECT METHOD
• THERE ARE SEVERAL METHODS
AS FOLLOWS:
• 1. SISTER METHOD: The survey
researchers ask women how many
of their sisters have died or had
children and at what age.

• 2. OTHER INDIRECT METHOD
include asking people about
siblings, parents and
children.
• 3. RESEARCH SURVEY.
• 4. NATIONAL SAMPLE SURVEY
• 5. SAMPLE REGISTRATION
SURVEY.

• 6. DEMOGRAPHIC METHODS :
• MODELS OF MORTALITY - Life
table, Gompertz models, hazards
models, multiple decrement life
tables, Brass relational logits.
MODELS OF FERTILITY - Hernes
model, Coal-Trussell models,
parity progression ratios.

• MODELS OF MARRIAGE :
Singulate Mean at marriage, Page
model.
• MODELS OF DISABILITY :
SAULLIVAN'S METHOD,
MULTISTATE LIFE TABLES.

• POPULATION PROJECTIONS: Lee
Carter, the Leslie Matrix.
• MODEL OF MIGRATION : Keyfitz.

APPLICATION-METHODS
OF DATA COLLECTION
I. PRIMARY DATA
collection is done by the individual
using:
1. Interviews.
2. Observation.
3. Questionnaires.
4. Diaries.
5. Critical incidents.

• SECONDARY DATA collection is
done by :
1.Census.
2. National Survey.
3. Registration of vital events.
4. Demographic studies.
5. Records.

INTERVIEWS
• Interviews are undertaken on
personal, one to one basis or in a
group.The advantages of interview
method are as follows.
1.It is the best means to collect an
indepth information.
2.The feedback and response rate is
good.

3.The information is recorded
immediately and complete.
4. Help can be provided immediately.

DISADVANTAGES OF
INTERVIEW
1. It is expensive and time
consuming.
2. Training is required in case of
employing many interviewers.
3. Pre fixed questionnaire are
required.

TYPES OF INTERVIEWS
• An interview can be of three types:
1. STRUCTURED.
2. SEMI STRUCTURED
3. UNSTRUCTURED.

OBSERVATION
• Is a method to record behavioural
pattern of people in a systematic
manner.
• The methods of observation
include: structured, un structured,
natural, personal, mechanical,
participant or non participant
observations.

• Observation method provides
information on what is actually
observed.
• Bias in observation method can be
eliminated by two observers.
• Hence this method has limitations
in eliciting accurate information.

QUESTIONNAIRES
• Questionnaire is a common
method of data collection.
• It takes time and expertise to
prepare a structured questionnaire.

• The questionnaire can be used to
interview for a direct data
collection or a telephonic survey
could be conducted.
• It can be posted, emailed or faxed.
• The main advantage of this method
is that there is no bias.

• The use of questionnaire is simple
but requires a certain level of
education and skill from
respondents.

DIARIES
• Diaries are used to record data
obtained from the individuals.
• The data expressed in the diaries
are an indepth information and can
be used for reseaech purposes.

CRITICAL INCIDENTS
• The critical incidents relating to
health - illness event is recorded
and used for arriving desicions
and policies regarding health
matters.

II.SECONDARY DATA
• The secondary data is collected
indirectly (not from inviduals) from
other sources such as hospital
records, census data etc.

SOURCES OF
DEMOGRAHIC DATA
• Census.
• Natioal Survey.
• Registration of vital events.
• Demographic studies.
• Records.

CENSUS
• Census is the direct method of
collection of demographic data.
• Census is conducted by the
government every 10 yrs.

• Census is an attempt to contact
every member of the population in
a country.
• Census not only provides
information regarding the number
of people, but other relevant
information (age, gender, marital
status, occupation, education,
employment status, migration,
language, religion etc.)

• A census covers social &
economic aspects of a population.
• It is conducted at the end of first
quarter of each decade.
• The census commisioner of India
guides, operates, and directs the
census.

REGISTRATION OF VITAL
EVENTS
• Registration of vital events is the
basis of vital statistics.
• Vital events refers to births, death,
migration, marriages, divorces,
foetal deaths are registration in
India.

• In 1873, Govt of India passed the
Birth, Deaths & Marriage
Registration Act.
• Indian states such as Karnataka,
Tamil Nadu etc have passed their
own acrs related to registration of
vital events.

• The main drawback in this
registration process is that it has
the provision only for voluntary
registration.
• So data is not accurate and
complete as people do not
voluntarily get the birth, death or
marriages registered.
• The data tends to be unreliable.

• The other reasons for
incompleteness include :
1. Illiteracy.
2. Ignorance.
3. Lack of concern.
4. Lack of motivation.
5. Lack of uniformity.
6. Multiple registration agencies.

NATIONAL SURVEY
• National Survey refers to the
survey conducted at central level
to collect the information related to
population from various states.

DEMOGRAPHIC STUDIES
• Studies conducted on demography
also provide data regarding the
population's education, occupation
etc.
• The demographic studies provide
information about the latest
demographic changes occuring
from time to time.

RECORDS
• Records available in hospitals
constitute the basic and primary
source of information about births
and deaths due to specific illness.
• Hospital data provides the
numerator. (not the denominator &
hence is incomplete)

ANALYSIS &
INTERPRETATION OF DATA
• The data thus collected should be
aranged in tables, charts,
diagrams, graphs, picture & curves
to stress important points.
• The data presented should be
based on the principles designed
to meet the criteria.

CHARACTERISTICS OF A
TABLE
• A table has a title, table number,
rows, coloums, row head, coloum
head.
• The data is presented as discrete
variables or as class intervals or
according to chronological order
or in alphabetical order.

CHARTS
• The data collected could be
represented in the form of a chart.
• The data contained in a chart is
more easy to understand and
retained easily than a table.

TYPES OF CHARTS :
1. BAR CHARTS. (simple. Compound,
Histogram)
2. LINE DIAGRAMS.
3. PIE CHARTS.
4. PICTOGRAM.
6. STATISTICAL MAP.
7. STATISTICAL AVERAGES &
DISPERSION OF MEASURES OF
VARIATION

• Bar charts are easy to prepare.
• They enable values to be
compared at a glance.
• In bar charts, bars proportional to
the magnitude are presented.

TYPES OF BAR CHARTS
1. Simple Bar
Chart.
2. Component
Bar Chart.
3. Histogram.

SIMPLE CHART
• The simple bar
chart represents
observations
proportional to
the magnitude.
• 2. The bars can
be either vertical
or horizontal.

COMPONENT BAR CHART
1. The component
bar chart represents
many components.
2. The representation
could be either as
vertical or as
horizontal bars.

HISTOGRAM
1.Histogram is a pictorical
diagram which consists
of series of blocks.
2.If the mid point of
histogrms blocks is
joined, then a line with
fluctuation is seen
3.frequency polygon is
obtained by joining the
mid points of histogram
blocks.

LINE DIAGRAM
• Line Diagram show the trend of
events occuring over a pasage of
time in continuation such as rise or
fall of AIDS cases over a period of
5 years.
• i.e. during the year
2000,2001,2002,2003 & 2004,

PIE CHART
• Pie charts are diagramatically
represenred in circles with the
radius "O". and at radius angle 360
degree.
• The area of the circle in the form of
segment which depends upon the
angle.

• These segments within the circle
are comparable.
• The segments are indicated in
percentages.
• To find out the angle at radius "O"
from the data, can be calculated
using a formula.

Degree to be
presented =
Given
percentage
100
x
360

Example
• 75% of people are literate & 25% of
people are illiterate.
• Angle for literate = 75 /100 x 360 =
270.
• Angle for illiterate = 25 / 100 x 360 =
90.

REPRESENTATION
90
270
75% LITERATE
25% ILLITERATE

PICTOGRAM
• In pictogram, small pictures or
symbols are used to present the
data.

STATISTICAL MAP
• Statistical maps are used to
present the data of different sizes.
• The data are presented in form of
shaded maps or dot maps.

• When there is a
need to indicate the
relationship of two
variables, scattered
diagrams are used.
• A linear relationship
is evident if the dots
are near or around a
straight line.
SCATERRED DIAGRAM

STATISTICAL AVERAGES
• Statistical averages refers to the
values in distribution, around
which other values are distributed
such as mean, median & mode.
• These are commonly used
averages which provide an
information of about central value.

DISPERSION OF MEASURES
OF VARIATIONS

NORMAL DISTRIBUTION CURVE
• Normal distribution curve is used
to represent the values for a very
large number of people after
creating narrow class intervals
with frequency distribution.
• The shape of the curve is based on
mean and standard deviation.

CHI SQUARE TEST
• Chi square test
is used to test
the significance
of difference
between two
proportions.

CORRELATION
• A correlation test is
used to find out the
relationship
between two
variables.
• E.g., Relationship
between level of
knowledge and
practice.

REGRESSION TEST
• Regression test
is used to find
out the
estimated value
of one variable
from value of
another.

INTERPRETATION OF
DATA
• The data collected is analyzed and
interpreted.
• The interpretations are then
generalized to public.

• The values interpreted should be in
simple so as to make it
understandable.
• While interpreting, the maximum &
minimum values should be shown
so as to have an estimation in
between.

• The data represented shoul be
presents as rates, ratios,
proportions, percentage, mean,
median, mode and normal curve.
• The demographic data are usually
analyzed and interpreted by tables,
charts, diagrams, pie charts,
pictogram etc.

DEMOGRAPHY

More Related Content

What's hot

Similar to DEMOGRAPHY

More from MAHESWARI JAIKUMAR

Recently uploaded

DEMOGRAPHY