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Venusn99 t1_isru8ft wrote

What type of graph is this?

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DiamondIceNS t1_istvv15 wrote

It's called a Sankey diagram.

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epolonsky t1_isufs70 wrote

And it’s exactly the wrong kind of chart for this data.

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DiamondIceNS t1_isulwnp wrote

Sankey diagrams are almost never the right answer.

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AgentNoShow t1_isumbuc wrote

When should they be used? What kind of diagram would be better?

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DiamondIceNS t1_isuomdp wrote

In my view, a Sankey is strongest when it also behaves like a flowchart, using the left-to right axis demonstrating a sequence of events rather than a hierarchy of categories. There's a comment chain in here complaining about the number of employment search Sankeys posted to this sub; as low-effort and overplayed as those posts may be, I think a Sankey suits that kind of use case optimally.

In this situation, where the data is purely hierarchical, I feel it would be clearer as a bar graph. Either a series of bar graphs broken up by manufacturer or a stacked bar graph. The Sankey here is doing... alright, I suppose. But the large amount of 1's in the data and how at the lowest level of breakdown the range of the data doesn't exceed 7, it's a little cluttered and difficult to parse.

IMO, I'd say the Sankey has the same weaknesses as pie charts.

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epolonsky t1_isuzjic wrote

I would say that Sankey is best when modeling a literal flow (e.g., electricity through a power station, wastewater through a processing plant, armies over a battlefield) and second best when modeling a metaphorical flow like a job search.

One big problem with how they get used in this sub that I’ve noticed is that the most popular Sankey tools online don’t allow for cyclical flows, which would often be a feature of physical flows.

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