Programme for International Student Assessment (PISA 2009)
Every 3 years the OECD assesses student scores on a number of educational skills. I have ordered the 66 countries by overall scores in 3 key areas.
Insights
- From the shape of the data the scores are roughly normal (bell-curved) with the extreme gaps larger than those at the middle.
- The United States is near the 3rd quartile in reading, the 2nd tercile in science, and mediocre in mathematics, below the OECD average.
- In general Asian nations score well, Shanghai consistently at the top and well ahead of #2.
- Finland is an interesting exception, and Canada does quite well.
Revisions and discussion
The data were copied from an OECD table and manipulated as follows:
- The datagraphic clearly shows both rankings and actual scores.
- The US is both highlighted and indicated with lines that point to its absolute score and relative rank, the latter being nonparametric.
- The key axes are labeled in the upper-right where they are most visible.
- The vertical axis was relabeled by rank (highest = 1, lowest = 66), which means that the first interval is only 9, and the last is only 6.
Technology and sources
- PDF saved as text file, then copied into Excel spreadsheet and saved as comma-delimited (csv) file.
- CSV file read by an R language script to generate plots with custom axes, symbology, etc.
- GIF file saved by Corel PaintShop.