Within the scientific community, journal impact factors play a large but controversial role in determining the kudos attached to a scientist's published research record.
It allows operating systems to perform power management operations via a smart battery charger based on remaining estimated run times by determining accurate capacity readings.
Most commonly, the growth of fish is measured by collecting individuals of varying sizes, measuring their length and determining their age by the otoliths.
Although the baryon per photon ratio is important in determining elemental abundances, the precise value makes little difference to the overall picture.