Adverb
observationally (comparative more observationally, superlative most observationally)
In an observational way.
We live at a very special time . . . the only time when we can observationally verify that we live at a very special time! Lawrence M. Krauss
Changes in physical constants are not meaningful if they result in an observationally indistinguishable universe. Source: Internet
Selenium has six observationally stable or nearly stable isotopes, 26 radioactive isotopes, and 9 isomers. Source: Internet
These predictions have not yet been tested either observationally or experimentally. Source: Internet
This resulted in an observationally based lunar calendar shifting relative to the seasons of the solar year. Source: Internet