Here's why:

* Instrumental refers to the use of instruments or tools.

* Observations are the act of noticing and recording something.

Therefore, instrumental observations are the data collected through the use of instruments. This can include:

* Scientific instruments: Telescopes, microscopes, thermometers, etc.

* Technological devices: Cameras, sensors, GPS devices, etc.

* Everyday tools: Rulers, scales, measuring cups, etc.

Let me know if you'd like more examples!