Graphical Presentation Of Data PDF

GRAPHICAL PRESENTATION OF DATA Prepared by: Mary May Noynay, LPT Objectives:  Identify methods in summarizing data;  Construct graphs out of raw data given ; Introduction  Summarizing data plays an important role in statistics.  One cannot interpret the data by merely u...

GRAPHICAL PRESENTATION OF DATA Prepared by: Mary May Noynay, LPT Objectives:  Identify methods in summarizing data;  Construct graphs out of raw data given ; Introduction  Summarizing data plays an important role in statistics.  One cannot interpret the data by merely using the raw data ( or raw data may not be that informative), but when data are presented in summary form, it becomes more interesting and meaningful to a researcher.  Thereare different methods in summarizing the data, such as the graphical methods and the tabular methods. Graphical Presentation Of Data  Good graphs convey information quickly and easily to the user.  Graphs highlight the salient features of the data.  Theycan show relationships that are not obvious from studying a list of numbers. Sales  They can also provide a convenient way to compare different sets of data.  Graphical presentation of data  Different situations call for different types of graphs, and it helps to have a good knowledge of what types are available.  The type of data often determines what graph is appropriate to use.  Qualitative data, quantitative data, and paired data each use different types of graphs. Lists of commonly used graphs:  Pareto /Bar Graph  Pie Chart/ Circle Graph  Line Graphs  Steam And Leaf Plot  Dot Plot  Histogram  Scatter Plots  Time-Series Graphs Pareto/ Bar Graph  Contains a bar for each category of a set of qualitative data.  Viewers can develop a clear mental image of comparisons among data series by distinguishing the relative heights of the bars. Pie Chart / Circle Graph  Pie graphs emphasize where your data fits in relation to a larger whole.  Itworks best when the data consists of several large sets. Too many variables divide the pie into small segments that are difficult to see. Use colour or texture on individual segments to create visual contrast. Line Graphs  Usefulin emphasizing the movement or trend of the numerical data over time, since they allow a viewer to trace the evolution of a particular point by working backwards or interpolating.  Highand lows, rapid or slow movement , or a tendency towards stability are all types of trends that are well suited to a line graph. Stem And Leaf Plot  Breaks each value of a quantitative data set into two pieces, a stem, typically for the highest place value, and a leaf for the other place values.  Itprovides a way to list all data values in a compact form. Dot Plot A hybrid between a histogram and a stem and leaf plot.  Eachquantitative data value becomes a dot or point that is placed above the appropriate class values. Minutes to Eat Breakfast Histogram  Another kind of graph that uses bars in its display. This type of graph is used with quantitative data.  Ranges of values, called classes, are listed at the bottom, and the classes with greater frequencies have taller bars. Scatter Plots  Displays data that is paired by using a horizontal axis (x axis), and a vertical axis (y axis). The statistical tools of correlation and regression are then used to show trends on the scatterplot. Time-series Graphs  Displays data at different points in time, so it is another kind of graph to be used for certain kinds of paired data.  The horizontal axis shows the time and the vertical axis is for the data values. These kinds of graphs can be used to show trends as time progresses. References:  Statistics Book of Dr. Liza Lorena Jala  https://www.thoughtco.com/frequently- used-statistics-graphs-4158380  Google images