Dot plot is almost the easiest of the graphs. It can be drawn by hand easily while collecting data. Dot plot will be very useful when the number of objects in our study is rather small such as up to 50 observations. Dot plot is generally used to investigate univariate (quantitative) data, but sometimes it is used to compare two variables. Essentially a dot plot is a one-dimensional scatterplot of observed values of a variable. In order to create a dot plot one needs to identify the lowest and the highest value of the data set first, then a horizontal axis is drawn and scaled so that it covers the lowest and highest values.