Understanding your users pt.1

Continuing from the last post where I talked about a pollution issue, and how I alleviated it. One of the things I found I did differently from others was using the pollution concentration unit instead of the air quality index.

You might be wondering what the difference is between PM2.5 concentration and air quality index (AQI for short).

The air quality index is calculated from a concentration value, and there are 2 major indexes that we're using. Chinese vs USA.

We use both indexes interchangeably, as there are many devices from China that measure PM2.5 in Chinese AQI, and some websites, like iqair.com, use USA AQI.

As you can see from the diagram above, both Chinese and USA AQI are calculated from the same base value, a concentration level (μg/m³), but they use different ranges entirely. This could cause confusion because, at a certain AQI, between Chinese and USA ones, they have different concentration levels.

And as the first user of this air pollution notification system, I want to be clear about what value means what. That's why I opted for the concentration level rather than the Air Quality Index. Since, for me, the concentration levels are the single source of truth, and when we're talking about the same concentration level, it's the same across the globe.

In the next episode, I'll talk about understanding the needs of my other pollution notification users.