In a dot plot, each value is represented by a dot placed along a number line.  

More than one dot above the same point means that the value was present in the data value more than once (one time per dot).  

A type of graph that uses bars, placed vertically or horizontally, to illustrate the frequency of data set categories. Bar graphs are particularly useful for categorical data sets.   

Bar charts allow for the visual comparison of data.  The bars should be spaced evenly and should be the same width.   

A bar graph is usually drawn with the bars separated, although sometimes you may see the bars without a separation.  

It is easy to confuse a Histogram with a Bar Chart.  While a bar chart displays categorical data, a histogram displays continuous data.  In terms of display, a histogram is always drawn without any separation between the bars.  

Another type of graphical data display in the field of statistics, the frequency polygon, uses lines to connect points that represent frequencies.  These points can be equated to the vertical bars in a histogram or bar graph.  

A frequency polygon is particularly useful because it visually demonstrates the "shape" of the distribution of the population.  That is, trends in the population may be easily demonstrated with a frequency polygon.  

A stem and leaf display is a type of data plot that divides a data values (numbers) into stems and leafs.  Part of the data value becomes the stem and part of the data value becomes the leaf. 

This type of data display keeps the actual data in tact but displays it in a better graphical form than a regular table or list.   In addition, it allows large data sets to be displayed in a more concise form.  

Take the following set of data values:  92, 96, 98, 118, 119, 121, 122, 123, 129, 135, 146, 147, 150.  Lets use data value 129 as an example.  129 can be divided into a stem and leaf in a few different ways.  12 can be the stem and 9 the leaf (put them next to each other and you get 129), or 1 could be the stem and 19 could be the leaf.   

Some data is collected over a period of time.  As a result, statisticians use a time series graph to examine the behavior of this data over time.    

A time series graph must have time on the x or y axis.  Visually, a time series graph may be represented in many forms, including a histogram or frequency polygon.  However, a frequency polygon or other line graph tend to be favored in making time series graphs.  

A pie graph or chart is a circle that is divided into different portions (slices).  The size of the slices depends on what percentage of the data falls into each "slice," or category.   

A pie graph may display both qualitative and quantitative data.  However, a pie graph is particularly useful and easy-to-use  for qualitative data.  

A Pareto chart is a form of bar chart.  It is usually used for categorical data.  In a Pareto chart, the horizontal axis represents the categories.  The bars, which represent data frequency, are ordered from largest to smallest so that interpreting the chart is more convenient.