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بسم الله الرحمن الرحيم. Graphical Presentation. Dr. Laila Mohamed Nofal Professor of Biostatistics High Institute of Public Health University of Alexandria. Graphical Presentation. Graphical presentation is the use of a graph to show the distribution of data. Why ?.
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Graphical Presentation Dr. Laila Mohamed Nofal Professor of Biostatistics High Institute of Public Health University of Alexandria
Graphical Presentation Graphical presentation is the use of a graph to show the distribution of data. Why ? • Attract the reader’s attention • A graph or diagram, provides an easily understood picture of the data. A suitable diagram is easier to grasp and leaves a more permanent impression of the main features of the data • To compare two or more distributions.
There are many varieties of graphs. The use of a particular type depends on: Type of data (quantitative continuous or discrete or qualitative) Type of table (simple or complex) Graphical Presentation
Histogram • For quantitative continuous variables • S.F.D.T only
Age in Years Distribution of patients by age in Hospital X, 2012
Frequency Polygon • Quantitative continuous variable • SFDT or Complex FDT
Example: Frequency Polygon
Figure (3): Distribution of patients by age and sex in Hospital X, 2012
Frequency Curve • Quantitative continuous variable • SFDT or Complex FDT • Points are joined by a smooth curve • The more the number of points (categories) the more smooth will be the curve