The document discusses biostatistics fundamentals, focusing on data collection and graphical presentation techniques, including histograms and frequency polygons. It outlines the characteristics, advantages, and disadvantages of various graphical representations, emphasizing their effectiveness in conveying complex information. Additionally, it describes different sampling methods, including census and random sampling, highlighting the importance of effective data presentation for analysis and decision-making.

1. skhot1976@gmail.com B.Sc.-III Paper- XIV (DSE –F26) Bioinformatics, Biostatistics and Economic Botany
skhot1976@gmail.com
Paper XIV
Unit. 2. Biostatistics
2.4 Graphical representation- Histogram and polygon
Dr. Sudhakar Sambhaji Khot
M.Sc., Ph.D., SET
Assistant Professor in Botany
Y. C. Warana Mahavidyalaya, Warananagar

2. skhot1976@gmail.com B.Sc.-III Paper- XIV (DSE –F26) Bioinformatics, Biostatistics and Economic Botany
Dr. S. S. KHOT 2
B.Sc. Part- III Botany
Paper- XIV DSE –F26
Bioinformatics, Biostatistics and Economic Botany
Unit 2: Biostatistics (11)
2.2 Collection and presentation of data:
Types of data, techniques of data collection- Census method,
sampling method- simple random, stratified and systematic sampling.
Classification, tabulation, graphical representation- Histogram and polygon.

3. skhot1976@gmail.com B.Sc.-III Paper- XIV (DSE –F26) Bioinformatics, Biostatistics and Economic Botany
Dr. S. S. KHOT
2.2 Collection and presentation of data:
Data – Set of facts expressed by individuals / reported by investigator
Presentation of data: Tabular method, and Pictorial / graphical Method
“A picture is worth a thousand words”
Advantages of pictorial/ graphical presentation:
 conveys information more effectively than words
 Can convey complex ideas more effectively
 Conveys messages with long lasting impact
 Can tell a story without words
 Useful for comparative analysis
 Useful for decision making
 Overcome language barriers
Disadvantages: Time consuming,
requires expertize, may create errors

4. skhot1976@gmail.com B.Sc.-III Paper- XIV (DSE –F26) Bioinformatics, Biostatistics and Economic Botany
Dr. S. S. KHOT
2.2 Collection and presentation of data: Graphical Presentation
‘Graphical representation: geometrical image of a data/ pictorial presentation ’
Characteristics of graph:
 The graph is drawn on graph paper
 Two intersecting lines (axis)
 Abscissa: X-axis
 Ordinate: Y-axis
 Origin point: intersect point (0,0)
 Quadrant I: +, +
 Quadrant II: -, +
 Quadrant III: -, -
 Quadrant IV: +, -
 Title of graph
 Scale on axis
Quadrant I: +, +
Quadrant II: -, +
Quadrant III: -, - Quadrant IV: +, -
Title of graph: …
Scale on X-axis
Scale on Y-axis
X-axis
Y-axis

5. skhot1976@gmail.com B.Sc.-III Paper- XIV (DSE –F26) Bioinformatics, Biostatistics and Economic Botany
Dr. S. S. KHOT
2.2 Collection and presentation of data:
Data Processing- Graphical representation- Histogram and polygon
‘Histogram: graph containing frequencies in form of vertical rectangles close to
each other. It is area diagram
Characteristics of graph:
 X-axis: class intervals
 Y-axis: frequency
 Rectangles without any gap in between
 2-Dimensional diagram
Advantages
 Simplifies complex data
 Easy to understand and memories
 Median and mode located easily
 Facilitates comparison
 Shows pattern of distribution

6. skhot1976@gmail.com B.Sc.-III Paper- XIV (DSE –F26) Bioinformatics, Biostatistics and Economic Botany
Dr. S. S. KHOT
2.2 Collection and presentation of data:
Data Processing- Graphical representation- Histogram and polygon
‘Polygon: (Frequency Polygon) histogram with straight lines joining the mid-points
of the top of the rectangles
Characteristics of graph:
 Polygon: figure with many angles
 Area diagram
 Rectangles without any gap in between
 Mid-points connected by straight lines
Advantages
 Simplifies complex data
 Easy to understand and memories
 Median and mode located easily
 Facilitates comparison
 Shows pattern of distribution
 Smooth transition betn classes

7. skhot1976@gmail.com B.Sc.-III Paper- XIV (DSE –F26) Bioinformatics, Biostatistics and Economic Botany