Changes in Size: Using Rates vs. Totals
"How Are We Doing?" Understanding Trends • 4m 56s
When we explore trends, it's easy to mistake a change in population size for a change in something else. This is why rates are useful. Rates tell us how something is changing per unit or member of the population, which lets us control for changes in the population.
Up Next in "How Are We Doing?" Understanding Trends
Change in Definition
Lots of the things that interest us have definitions that are not stable over time, especially in areas involving human behavior. When these definitions change, it can affect data on those things. Does this mean definitions should never change? No. But when they do, we should be aware of those ch...
Changes in Behavior/Environment
There is a difference between what is happening in the environment and what we observe in our data. Sometimes, the environment (or a behavior in it) changes in ways that affect our data and create a mistaken impression of change in the thing that really interests us. When you see a big change, co...
Changes in How We Gather Data
Every change in how we gather data can affect the likelihood of observing the things that interest us. A leader who knows when those changes happen will be better positioned to understand how trends may be the result (at least in part) of changes in the approach to collecting data.