In Minitab, the height of each bar on a graph represents a statistic for a category (categorical data) or interval (continuous data).
Suppose your bar chart summarizes the following data:
Chart Sum(Data)*Machine; Group Operator; Bar; Color Colors.
The base position is a value from which the bars originate. Graphed values greater than the base position project up from the line; graphed values less than the base position project down from the line. You can change the base position, for example, to show distance from a target value.
Suppose each person on your sales team has a goal of $12,000 for a month. The base position 0 makes it easy to compare total sales. To emphasize the relationships to the target value of $12,000 (12 on the y-scale), you set the base for the bars to 12 and draw a reference line there. Now, you can see that Steve's totals are below the goal, Mary's are slightly above, and Roberto and Bill's are the highest.