Graphs are now almost exclusively computer generated and epidemiologists become more and more dependent on the possibilities and limits of computer graphic software packages.
Whatever the software used some principles should probably be respected. We should avoid three dimensional graphs. They do not improve communication and they are not easier to interpret, rather the opposite. Colours should be selected according to complementary colour criteria. Many software programmes do not allow the user to construct histograms. What is frequently called a histogram is in fact a bar graph. Units and scales on the x and y axes are not always clear in some of the software packages. Most software does not allow users to create a standard epidemic curve with one square representing one case. Particularly when the x-axis illustrates time, most of the software programmes are not flexible enough to comply with what epidemiologists need.
Personal productivity tools are commercial products designed to handle standard computing tasks such as word processing, numerical analysis, data manipulation and storage, and data presentation. Typical products include :
1. Statistics Canada, Power from data! - The computer industry