“That way, you can readily see the difference between the three It’s more effective than three graph lines on top of each other.”
Another tool is a bar chart, with bars of different sizes—horizontal or vertical.
NAME THAT CHART With Apple’s Macintosh and the Microsoft chart graphics package from Microsoft, you can whip up charts like the ones below. Chart will even pick up numbers from a sister spreadsheet program, Multiplan. My thanks to artist Jo Steele, who works for the Dartmouth College Computer Center and is a partner in Northtronics Associates. Oh, and don’t blame Jo for the use of those over-mentioned woks. My mistake. Next time I’ll use dishwashers or watermelons.
Do broad trends count more than the numbers themselves? Then use a line chart, a graph with the outlines of hills and valleys. Amalgamated Wok might decorate each sales rep’s office with such a chart, at which a myopic CEO could smile or frown as he walked in.
Use a bar chart to compare sizes or emphasize differences, including those over time. With the bar chart, you might contrast 1979 wok sales with 1984’s.
Don’t normally use the bar chart, however, to illustrate trends. For that, it’s usually back to the old line or curve chart.
Just the same, Mike Slade, a product manager at Microsoft, says: “There are times when you can illustrate trends successfully using overlapping bar charts—with bars of different colors or patterns.
A curve chart or area chart is just a line chart with the area below the lines filled in. This is a deluxe version with different shadings indicating different years. A no-frills area chart might actually be easier on the CEO’s eyes than would a line chart without shading.