Before the advent of computers, all data was written in notebooks. One of Leonardo da Vinci's notebooks, above, is an example, as are the notebooks by the great scientists of the past.
While observation by eye is still used today, more often than not we automate readings by electronics. In any given day, billions of sensors worldwide take readings of heat, light, wind, etc. But where does that data go?
To record and analyze readings, it is easiest for most folks to use a spreadsheet. Available on all computer platforms, a spreadsheet is one of the first programs people learn. And, the analytical capabilities (re. plotting/graphing) are excellent.
This guide will quickly allow you to learn about placing data readings directly into the spreadsheet of your choice, A Circuit Playground Express and it's multitude of sensors, will log data to a spreadsheet and an Android phone.
Or a standard USB OTG cable adapter