Akurasi jeung présisi itu apa sih? Jelaskan dalam bahasa sunda ya

Dina sains, rékayasa, industri jeung statistik, akurasi nyaéta tingkatkacocogan ukuran atawa lobana itungan kana nilai sabenerna (nilai nu bener). Akurasi pakait raket jeung presisi, disebut ogé bisa dijieun deui atawa diulang deui, tingkat nu dina ukuran atawa itungan saterusna nembongkeun hasil nu sarua atawa ampir sarua. Hasil itungan atawa ukuran bisa akurat tapi teu présisi; présisi tapi teu akurat; atawa teu présisi jeung teu akurat. Hiji hasil disebut valid lamun akurat jeung presisi. Watesan nu pakait dina survey nyaéta kasalahan (variabel acak dina panalungtikan) sarta bias (teu-acak atawa akibat langsung nu disababkeun ku ayana hal nu teu pakait ku variabel mandiri).

Akurasi vs presisi - analogi target

Akurasi nyaéta tingkat kadeukeutan sedengkeun présisi nyaéta tingkat kamampuh dijieun deui. Analogi dipaké di dieu keur nerangkeun béda antara akurasi jeung présisi nyaéta babandingan target. In this analogy, repéated méasurements are compared to arrows that are fired at a target. Accuracy describes the closeness of arrows to the bullseye at the target center. Arrows that strike closer to the bullseye are considered more accurate. The closer a system's méasurements to the accepted value, the more accurate the system is considered to be.

To continue the analogy, if a large number of arrows are fired, precision would be the size of the arrow cluster. (When only one arrow is fired, precision is the size of the cluster one would expect if this were repéated many times under the same conditions.) When all arrows are grouped tightly together, the cluster is considered precise since they all struck close to the same spot, if not necessarily néar the bullseye. The méasurements are precise, though not necessarily accurate. Further example, if a méasuring rod is supposed to be ten yards long but is only 9 yards, 35 inches méasurements can be precise but inaccurate. The méasuring rod will give consistently similar results but the results will be consistently wrong.

However, it is not possible to reliably achieve accuracy in individual méasurements without precision — if the arrows are not grouped close to one another, they cannot all be close to the bullseye. (Their average position might be an accurate estimation of the bullseye, but the individual arrows are inaccurate.) See also Circular error probable for application of precision to the science of ballistics.

Accuracy and precision in logic level modeling and IC simulation

As described in the SIGDA Newsletter [Vol 20. Number 1, June 1990] a common mistake in evaluation of accurate modéls is to compare a logic simulation modél to a transistor circuit simulation modél. This is a comparison of differences in precision, not accuracy. Precision is méasured with respect to detail and accuracy is méasured with respect to réality. Another reference for this topic is "Logic Level Modelling", by John M. Acken, Encyclopedia of Computer Science and Technology, Vol 36, 1997, page 281-306.