About the Visualization
We show the ebb & flow of important keywords as they appear in different contexts (history, literature, film, music, etc.) in Wikipedia.

Try this!
You can compare different contexts across years – try selecting different contexts to view from the lists to the right of each graph, and try selecting a range of years to zoom in on from the mini graph below. Click an area to filter the graphs on that word.

About the Dataset
You may have noticed that, for example, World War II can appear across the entire timeline, even though it only occurred from 1939-1945! There's still a spike from 1939-1945 in some contexts, but events before then influenced the war and events after it were influenced by the war. This same reasoning applies to the rest of the data. That's part of why this dataset is so interesting.

How We Count Keywords
We find the yearly count of each keyword based on how the Wikipedia articles' internal links from that year's set of articles link to other articles – the totals for each link become the counts of keywords that we visualize. The initial sample of 18 keywords we show here is taken from a Gallup poll on the most important events of the 20th century.