VARIABLE A measurable quantity which can vary from one individual or object to another is called a variable. A measurable quantity which can vary from one individual or object to another is called a variable. A variable that can assume any value within a given range is called a continuous variable. A variable that can assume any value within a given range is called a continuous variable. A variable which can assume only some specific values within a given range is called a discrete variable. A variable which can assume only some specific values within a given range is called a discrete variable.

DATA Data which is described by a qualitative variable is called qualitative data. E.g. religion, gender, Data which is described by a qualitative variable is called qualitative data. E.g. religion, gender, Data described by a quantitative variable are called quantitative data. E.g. height, weight etc. Data described by a quantitative variable are called quantitative data. E.g. height, weight etc.

DATA CLASSIFICATION The process of arranging data into classes or categories according to some common characteristics present in the data. The process of arranging data into classes or categories according to some common characteristics present in the data. Classification is arranging of things in groups or classes according to their resemblences and affinities. Classification is arranging of things in groups or classes according to their resemblences and affinities.

PRESENTATION OF DATA TEXT PRESENTARION TEXT PRESENTARION TABULAR PRESENTATION TABULAR PRESENTATION DRAWING DRAWING

TABULAR PRESENTATION A table is a systematic arrangement of data into vertical columns and horizontal rows. A table is a systematic arrangement of data into vertical columns and horizontal rows. The process of arranging data into rows and columns is called tabulation. The process of arranging data into rows and columns is called tabulation.

TABULATION Simple table Simple table Complex table Complex table PrinciplesPrinciples Table should be numbered Table should be numbered Each table has a Title---brief & self explanatory Each table has a Title---brief & self explanatory Headings of column & rows should be clear Headings of column & rows should be clear Data must be presented a/c to size, importance, chronologically, alphabetically or geographically. Data must be presented a/c to size, importance, chronologically, alphabetically or geographically. No too large table No too large table Foot note may be given. Foot note may be given.

STATISTICAL TABLE THE TITLE THE TITLE THE STUB THE STUB THE BOX-HEAD THE BOX-HEAD THE BODY THE BODY

TABLE I Population of Punjab & Baluchistan (thousands) census PunjabBaluchistan MaleFemaleTotalMaleFemaleTotal

SIMPLE TABLE Table 1 Table 1 Population of Pakistan Population of Pakistan year Population (millions)

COMPOUND TABLE Table III Table III Sex wise fatality rate of untreated patients Sex wise fatality rate of untreated patients AttributeMenWomenTotal Attacked Deaths12820 %age died

COMPOUND TABLE Table II Colour choices of medical students of shirtS SexWhiteBlueYellowGreenPinkTotal Male Female Total

DATA Arrangement of data is based on Arrangement of data is based on Classification Classification Purpose of table Purpose of table Alphabetically Alphabetically Geographically Geographically According to magnitude According to magnitude Historically Historically Customary classes Customary classes Progressive arrangement. Progressive arrangement.

FREQUENCY DISTRIBUTION Is a tabular arrangement of data in which various items are arranged into classes and the no. of items falling in each class (class frequency) is stated. Is a tabular arrangement of data in which various items are arranged into classes and the no. of items falling in each class (class frequency) is stated. Grouped data Grouped data Class limits Class limits Class interval Class interval

FREQUENCY DISTRIBUTION Data is split into groups-called--- class intervals Data is split into groups-called--- class intervals No. of items (frequency) is written in adjacent column No. of items (frequency) is written in adjacent column

FREQUENCY DISTRIBUTION TABLE TABLE II TABLE II Age distribution of patients on Monday Age distribution of patients on Monday AgeNumber of patients

FREQUENCY DISTRIBUTION TABLE TABLE II TABLE II Weight of medical students of SZMC Weight of medical students of SZMC Weight (Kg)Number of students and above28

FREQUENCY DISTRIBUTION DRAWINGS After class wise and group wise tabulation, the frequencies of a characteristic can be presented by: After class wise and group wise tabulation, the frequencies of a characteristic can be presented by: GraphsGraphs DiagramsDiagrams By lines By lines Dots Dots Figures. Figures.

GRAPHIC AND DIAGRAMATIC PRESENTATION Useful method for presentation of data Useful method for presentation of data Impact on imagination of people Impact on imagination of people Diagrams are better retained in mind of human. Diagrams are better retained in mind of human. More attractive More attractive Comparison of data Comparison of data

GRAPHIC AND DIAGRAMATIC PRESENTATION Bar chart Bar chart Multiple bar chart Multiple bar chart Component bar chart Component bar chart Histogram Histogram

BAR CHART

COLUMN CHARTS

BAR CHART

MULTIPLE BAR CHART

COMPONENT BAR CHART

HISTOGRAM Reaction (mm) Frequency TOTAL229

FREQUENCY POLYGON

LINE DIAGRAM

PIE CHART

Tuberculin reaction

FREQUENCY CURVE When no. of observations is very large and group interval is reduced, the frequency polygon tends to lose its angulations giving place to a smooth curve known as frequency curve. When no. of observations is very large and group interval is reduced, the frequency polygon tends to lose its angulations giving place to a smooth curve known as frequency curve. This provides a continuous graph that is obtained in normal distribution of individuals in a large sample or of means in populations. This provides a continuous graph that is obtained in normal distribution of individuals in a large sample or of means in populations.

Normal distribution