Bar graphs best illustrate results that are gathered at one given time and are independent of each other. Results of surveys, then, are best captured in bar graphs. The bar graph below was used by Soraya J. NetoAlvarez to summarize the chances of projects of different sizes – as expressed in terms of total project costs – to be successful.
As shown in the bar graph, the x- axis or the abscissa presents the percentages of success achieved by projects while the y-axis or the ordinate presents the different scales or sizes of projects. The bar graph’s x-axis is divided into equal intervals of 10 percent, from 0 percent at the meeting point of x- and y-axes to 60 percent going to the right. Its y-axis, meanwhile, scales the sizes of the project from the same zero-point of x-axis to less than $750k as the smallest size in terms of project cost to the designated biggest size, over $10 million, as the highest point.
The highest points of both x- and y-axes are set based on the given data to be plotted in the bar graph. In the case of the subject data, the highest percentage of success attained is 55 percent. As to the project sizes, the group that conducted this particular survey formed the scale of sizes and since all the companies that participated in the survey have total project costs that did not go beyond $10 million, then the highest point in the y-axis has been set at over $10 million.
With the x- and y-axes accordingly labeled, the percentages of success of each of the identified project sizes are next plotted as horizontal bars spanning the space from the point that represents 0 percent to the point that represents the exact percentages in the x-axis. Once all the data have formed part of the bar graph, the result is an illustration that gives at one glance the general picture of the details gathered in the course of the survey.
Thus, the bar graph effectively conveys that based on the survey conducted, the small-sized projects turned out to be more successful, while the big-sized projects were the ones with lower chances of success. These same information bits are included in the written lines, but it cannot be argued that the inclusion of the bar graph in the final output serves to provide a good grasp of the data.
Reference
- NetoAlvarez, S. (2003). Project Management Failure: Main Causes. Retrieved January 24, 2009 from http://faculty.ed.umuc.edu/~meinkej/inss690/netoalvarez.pdf.
