I commonly analyze packages of scientific journals, and we often want to know if there are titles that are not being used that we can stop subscribing to. I usually graph usage (download count) vs. publications (how many papers did our authors publish in that journal) for a given year. Generally, high use journals will have more publications, though not always.
Creating this graph every year gives me multiple independent snapshots of each journal's performance. But how can I best compare these yearly graphs to each other? Is this low (or high) performing journal from this year one that is a common underachiever, or was this just an outlier year? The packages usually contain anywhere from 70-150 individual journal titles, so the plots are fairly cluttered already, which is why I am reluctant to color-code by year and symbol-code by title.
What are some recommendations to track a journal title over time, while also seeing the bigger picture?
Regarding "But how can I best compare these yearly graphs to each other?", I would generally advocate using a local data filter, possibly with animation, with your favourite graph types. In this case I would define 'Year' to have Modelling Type 'Ordinal' and filter by that. You may also need to 'Lock Scales' of graphs to facilitate the comparison.
