A) Tabulation : Frequency distribution Table : - Quantitative - Qualitative B) Drawing: (Graphs / Charts/ Diagrams) Quantitative Data : i) Histogram ii) Frequency Polygon iii) Frequency Curve iv) Line chart /graph v) Cumulative Frequency Diagram / Ogive vi) Scatter or Dot diagram vii) Stem & Leaf plot Qualitative Data : i) Bar diagram (Simple / Multiple / Proportional) ii) Pie or Sector chart iii) Pictogram
General principles in designing table :
The tables should be numbered e.g., Table-1, Table-2 etc.
There should be a brief and self-explanatory title, mentioning time, place & persons.
The headings of columns and rows should be clear and concise
The data must be presented according to size or importance; chronologically, alphabetically or geographically
Data must be presented meaningfully
No table should be too large
Foot notes may be given, if necessary
Total number of observations (n) i.e the denominator should be written
The information obtained in the table should be summarized beneath the table
TABLE-1 Population by sex in Kolkata urban area in 2001 Source: Health on the March 2004-05, Govt. of West Bengal Characteristics Population (in million) % Male Female 7.07 6.14 53.52 46.48 Total 13.21 100.00
Frequency distribution table for qualitative data Characteristics Population (in million) % Male 7.07 53.52 Female 6.14 46.48 Total 13.21 100.00
Frequency distribution table for quantitative data Pulse rate/minute No of medical students Percentage 51-60 2 1.33 61-70 22 14.67 71-80 56 37.33 81-90 55 36.67 91-100 14 9.33 101-110 1 0.67 Total 150 100.00
lists classes (or categories) of values, along with frequencies (or counts) of the number of values that fall into each class
Cumulative Frequency Table Cumulative Frequencies Table 2-6 0 - 2 20 3 - 5 14 6 - 8 15 9 - 11 2 12 - 14 1 Rating Frequency Less than 3 20 Less than 6 34 Less than 9 49 Less than 12 51 Less than 15 52 Rating Cumulative Frequency
Frequency Tables 0 - 2 20 3 - 5 14 6 - 8 15 9 - 11 2 12 - 14 1 Rating Frequency 0 - 2 38.5% 3 - 5 26.9% 6 - 8 28.8% 9 - 11 3.8% 12 - 14 1.9% Rating Relative Frequency Less than 3 20 Less than 6 34 Less than 9 49 Less than 12 51 Less than 15 52 Rating Cumulative Frequency Table 2-6 Table 2-5 Table 2-3
The widths of the bar should be equal
The bars are usually separated by appropriate spaces with an eye to neatness and clear presentation. The spaces between two bars are usually kept equal to the width of the bars.
The length of the bar is proportional to the frequency.
A suitable scale must be chosen to present the length of the bars.
The Y-axis corresponds to the frequency in vertical bar diagram, whereas the X-axis corresponds to the frequency in a horizontal bar diagram
Simple Bar Diagram
HIV+ve cases in six districts of West Bengal in 2004
Simple ar Diagram each bar represents frequency of a single category with a distinct gap from another bar . .
Multiple / Compound Bar diagram show the comparison of two or more sets of related statistical data .
Component /Segmented Bar diagram
to compare sizes of the different component parts among themselves
also show the relation between each part and the whole.
Causes of Maternal deaths of West
Bengal in 2005
For for qualitative or discrete data
Areas of sectors are proportional to frequencies
Angle (degree) of a sector=
Class % X3.6,
Expressing proportional components of the attributes
compared with that of other segments as well as the whole circle.
A histogram is a bar graph that shows the frequency of each item. Histograms combine data into equal-sized intervals.
There are no spaces between the bars on the histogram.
A line graph uses a series of line segments to show changes in data over time.
Plot a point for each data item, and then connect the dots with straight line segments.
Refer to page 336 for the line graph.
of histogram blocks
When no. of
very large: Frequency
Polygon loses it’s
angulations & giving
a smooth curve:
Frequency Distribution Haemoglobin Level
variations by time
Trend of an event occurring over a time
Year 1901 1911 1921 1951 1961 1971 1941 1931
Line Chart or Graph
Growth rate in India from 1921-1931 to 1991-2001
the trend of an event occurring over a period of time
• • • • • • • • • • • • • • 0 0.0 0.5 1.0 1.5 10 20 • NICOTINE TAR A plot of paired (x,y) data with the horizontal x-axis and the vertical y-axis. will discuss scatter plots again with the topic of correlation. Point out the relationship that exists between the nicotine and tar – as the nicotine value increases, so does the value of tar. • • • • • •