BV M10 Lec 2 Presentation of data and frequency distribution.pptx

Community

1. Presentation of DATA Prof. Dr Rubina Mumtaz HOD, Community Dentistry BV M10 Lecture 2

2. Learning Objectives At the end of this lecture, students will be able to: Demonstrate presentation of data in form of Tables, Graphs, Charts and Maps

3. Presentation of Data Methods of presenting data Numerical presentation Tables Graphical presentation Graphs, charts and maps

4. Tables A table is the simplest form of summarizing a set of variables and can be used for all types of numerical data Table is made up of rows titled stubs and columns titled Captions and corresponding cells that show their relationship How often something occurs is called Frequency Data placed in tables are called Frequency Distribution Tables or contingency tables Frequency distribution tables can range from simple to complex

5. Simple Frequency Distribution Table smokers Non-smokers Female 30 25 Male 45 16 TITLE Gender based distribution of Smokers and non-smokers in our study 2 by 2 Table Variable A B X Y Footnotes

6. Distribution of 20 lung cancer patients and 40 controls at Hospital X 2016 according to smoking Complex Frequency Distribution Table Smoking Lung cancer Total Cases Control No. % No. % No. % Smoker 15 75% 8 20% 23 38.33 Non smoker 5 25% 32 80% 37 61.67 Total 20 100 40 100 60 100

7. Presentation of Data Cont ’ Numerical presentation – Tables Graphical presentation – graphs, charts Mathematical presentation- ✔

8. GRAPHICAL PRESENTATION OF DATA Three categories of graphical presentation: Graphs drawn using Cartesian coordinates Bar Chart Stacked Bar Histogram Line graph Frequency Polygon Scatter plot Box plots Pie Charts Statistical Maps

9. Bar Chart Common for nominal or ordinal data X-axis denote the variable (1 or more) Y-axis denotes the frequency – height varies Bars are of equal width Bars are separate to avoid implying continuity

10. Stacked bar A stacked bar is like the bar chart, except that each series value is “stacked” on the value of previous series, instead of being set out side-by-side

11. Histogram Commonly used for discrete or continuous data X-axis denotes numerical range of variable; width of bars equal, hence range equal Y-axis denotes frequency

12. Line Graph Often used to display changes over time; x-axis denotes time and y-axis frequency

13. Frequency Polygon Like a line graph but based on histogram axes. Constructed by placing a point at center of each interval (bar) and connecting the points

14. A frequency polygon is used to compare changes over time

15. Scatter Plot A scatter plot can display both discrete or continuous data Uses a single horizontal axis; ideal for indicating relative position of each data point Two types One-Way Two-Way

16. Two way scatter plot A two-way scatter plot is used to compare two different continuous variables X-axis denotes one variable Y-axis denotes other variable Can be used to compare same data in different times or places

17. Two-way scatter plot of prevalence of (under-5-year-old) child stunting and prevalence of adult female obesity in African countries

18. Box plot Also called Box and Whiskers Plot Box plots are similar to one-way scatter plots in that they require one axis But instead of showing each and every variables, Box plots only display a summary in terms of quartiles of the data i.e. percentiles The maximum, minimum and median values are plotted and the size of the box above and below the median indicates the position of the data in the percentiles Can be used to compare groups

19. IQR- Interquartile Range ; also called the Middle 50% IQR is also called H-Spread It is the measure of statistical dispersion Difference between the 75 th Percentile and 25 th Percentile

20. Box and whisker plots for systolic blood pressure of screened cats

21. GRAPHICAL PRESENTATION OF DATA Three categories of graphical presentation: Graphs drawn using Cartesian coordinates Bar Chart Histogram Line graph Frequency Polygon Scatter plot Box plots Pie Charts Statistical Maps

22. Pie Chart A type of graph in which a circle is divided into sectors that each represent a proportion of the whole.

23. Statistical Maps Used for data regarding geography-related variables e.g. rainfall, population density, per capita income, GDP, GNP, crops, distribution of disease burden etc

24. Global Distribution of Forests and Woodlands

25. Questions? Thank you