One of the things about being in a position of organizational power – whether you’re an internal unit head or a library director – is that people will be constantly trying to convince you to do certain things. Those things may be micro (“I need a raise”; “We need more student employees”) or  macro (“The library needs a new remote-work policy”; “The library needs to do more to promote diversity, equity, and inclusion”), or they may be somewhere in between. But you will regularly be dealing with arguments both in favor of and against doing particular things, and the people advancing those arguments are likely to offer data in support of their contentions.

And here’s something I’ve noticed about how people present data: when they use percentages but don’t tell you raw numbers, or use raw numbers but don’t tell you percentages, you should be cautious in accepting the data at face value. Because in many contexts, either the raw numbers or the percentages – when presented alone – will be misleading.

For example, consider the following statements: