Source: L. Krempel and T. Plümper, "Exploring the Dynamics of International Trade by Combining the Comparative Advantages of Multivariate Statistics and Network Visualizations", Journal of Social Structure, Vol. 4, No. 1
Description: This image shows the trade relationships in 1994 between the 26 biggest trading countries in the world. The arrows represent trade in the direction that they are pointing and their thickness represents the volume of the trade. The distance between the country nodes represents the distance between the capitals of the countries. Finally, the different colors of the connections represent the error in the trade flow estimates.
Critique: This image is a poor visualization of the data for many reasons. The first problem is that there is too much information displayed. Since there are so many links, many of the countries names are hidden by connectors, and it is virtually impossible to follow the links since they cross over so. Also, the color choice is distracting since they are mostly highly saturated and draw too much focus to them. Another issue is when countries are close geographically, like Canada and the USA , it is nearly impossible to differentiate the values. Finally, there is a bar graph in the top corner that is supposed to show the error rates in the data, but there is no text indicating what it is supposed to do.
Source: "Flat income tax: A dip in the middle", The Economist, Sep 8th 2005
Description: This image shows the impact of a flat income tax that is proposed in Britain , eliminating multiple tax brackets like we have here. For different income levels, it shows how the imposition of this tax will affect them (gain or loss).
Critique: This is a good visualization because it concisely shows the relationship between annual income and the new flat rate income tax. It quickly and clearly allows the viewer to determine that the average income earner is affected negatively, where as the low and high earners gain from this change. This visualization has logical increments that are evenly spaced on both scales, meaning that it is simple to determine the effect on the income that the viewer wishes to look at. Also, the graph is labeled very clearly so that the text from the article is not required to understand what it is showing. The graph even states the basis of the calculations for the flat tax rate.