What makes one country better than another in science? It's not an easy thing to measure. Publishing research papers is a good way to get a bead on basic research, but it doesn't say much about whether a nation is taking advantage of those good ideas. For this, other metrics come into play. Patents give a clue as to how well a country is exploiting its ideas for commercial gain. What a nation spends on R&D captures not only what universities and government research programs do but also the contribution from industry. How many students a nation educates in science and technology disciplines is a key metric, but little data are available.

The rankings of the top 25 nations that snake through the middle of these two pages are based on preliminary data from Digital Science, a sister company to Nature Publishing Group (which owns Scientific American). It has assembled a database of research papers published in top peer-reviewed journals around the world and has organized them by nation of origin. The table at the left shows the rankings for this metric and others—patents, R&D expenditures and doctoral candidates produced.

Interactive by Jan Willem Tulp