1. EPIDEMIOLOGY

2. CLASSIFICATION OF
STATISTICAL DATA
• According to Nature
Quantitative data
Qualitative Data
• According to Source
Primary data
Secondary data

3. CLASSIFICATION OF
STATISTICAL DATA
• According to Arrangement
Ungrouped data
Grouped Data
• According to measurement
Discrete data
Continuous data

4. PRESENTATION OF STATISTICAL
DATA
• Tabular form
Reference purpose or general
Special purpose or text
• Bar charts
Subdivided
Multiple
• Pie diagram
• Time series line graph

5. PRESENTATION OF STATISTICAL
DATA
• Pareto chart
• Histogram
• Ogive
• Lorenz curve

6. SOURCES OF DATA
Primary Secondary Tertiary
Autobiographies Abstracts
correspondence Biographies bibliographies
descriptions of prior books & papers on a chronologies
travel topic classifications
diaries literary criticism & dictionaries &
literary works interpretation encyclopaedia
interviews history & historical criticism directories
personal narratives political analyses guidebooks and manuals
paintings and reviews of law and population registers
photographs legislation statistics
essays on morals and ethics
analyses of social policy
study and teaching material

7. SAMPLING
• It is concerned with the selection of a subset of
individuals from within a population to estimate
characteristics of the whole population.
• Researchers rarely survey the entire population
because the cost of a census is too high.
• The three main advantages of sampling are that
the cost is lower, data collection is faster, and
since the data set is smaller it is possible to
ensure homogeneity and to improve the
accuracy and quality of the data.

8. METHODS OF SAMPLING
• Simple random
• Systematic
• Stratified
• Cluster
• Probability proportional to size
• Quota sampling
• Accidental
• Line-intercept
• Panel