STATISTICS : PRESENTATION OF DATA

Data can be presented in three ways:

Textual presentation
Tabular presentation
Diagrammatic presentation

1. Textual Mode of presentation is layman’s method of presentation of data. Anyone can prepare, anyone can understand. No specific skill(s) is/are required.

2. Tabular Mode of presentation is the most accurate mode of presentation of data. It requires a lot of skill to prepare, and some skill(s) to understand. Table facilitates comparison.

But, Table should be good enough as per some points of view:

1. Appealing
2. Well-balanced
3. Compulsory Title and Table Number
4. Title should be self-explanatory
5. Units must be properly mentioned
6. Comparison should be easy
7. Sources and footnotes (if any) must be mentioned at the bottom

Below is a sample of how a table should look like:

Table No. 1: Format of a table

CAPTION

Height (cm)

Weight (kg)

Age (Years)

STUB

BODY OF THE TABLE

*Sources: 1. Kailasha Foundation – Fun & Learn Portal LMS Directory
*Footnotes: The entire upper part of the table is called BOX HEAD.

3. Diagrammatic Mode of Presentation:

A. Non-Frequency Diagrams: Non-frequency diagrams correspond to the data which are NOT frequency data.
(a) Bar Diagrams
(b) Line Diagrams (Historiagram)
(c) Pie Diagram or Pie Chart

B. Frequency Diagrams: Frequency Data are presented. Mostly class-intervals are presented via this mode. Three most common frequency diagrams are:
(a) Histogram
(b) Frequency Polygon
(c) Ogives: (i) Less than type Ogives (ii) More than type Ogives

Notes:

1. Bar Diagram and Line Diagram are inter-convertible
2. Bar Diagram and Line Diagram can both be of simple and multiple types
3. Multiple bar diagram or Multiple Line diagram is used when two related series (in same unit) are to be compared
4. Multiple axis bar diagram or Multiple axis Line diagram is used when units in the two series are different

Frequency, when continuously added from lower to higher, is called "less than cumulative frequency" and when continuously added from higher to lower, is called "more than cumulative frequency". 

A particular frequency, divided by total is called relative frequency.

Frequency divided by class size is called Frequency Density.

ILLUSTRATIONS OF PRESENTATION OF DATA:

Bar Diagrams:

Line Diagram:

Pie Chart:

Histogram:

Multiple Bar Diagram:

Frequency Polygon:

Ogives:

FREQUENCY CURVE:

A smooth join of all vertices of a frequency polygon. This is broadly divided into four shapes:

(i) Bell Shaped (Most Common Shape)
(ii) U-Shaped
(iii) J – Shaped: Simple J – shaped & Inverted J – Shaped
(iv) Mixed Curve (Second Most Common Shape)

GLOSSARY:

1. CENSUS: The collection of data from every element in a population or universe or arena of statistical enquiry.
2. SAMPLE: The collection of data from subgroup or subset of the population.
3. FREQUENCY: The number of times a certain value or class of values occurs.
4. CUMULATIVE FREQUENCY: The running total of the frequencies at each class interval level.
5. FREQUENCY DISTRIBUTION: The organization of raw data in table form with classes and frequencies.
6. CLASS LIMITS: The originally assigned extreme values of classes are called class limits, viz. Lower class limit and upper class limit.
7. CLASS WIDTH: The difference between the upper and lower boundaries (NOT limits) of any class.
8. CLASS BOUNDARY: After making the distribution continuous, the upper class boundary of a class becomes equal to the lower class boundary of the next class.
9. CLASS MARK: The mid-point of any class is called the class mark.