Name: how measurement errors affect results
Uploaded: 2023-04-30T12:12:04.000Z
Duration: 1 min 20 s
Channel: JoVE

K12 Standards

Florida Department of Education

High School

Nature of Science

SC.912.N.1

SC.912.N.1.4

Random and Systematic Errors

Częstym problemem są błędy w procesie pomiaru. Takie błędy można podzielić na dwie kategorie: losowe i systematyczne.
Błędy losowe są wynikiem niespójności w procesie pomiarowym lub zmian w mierzonej ilości. Powodują one wahania, zbyt wysokie lub zbyt niskie, wokół wartości rzeczywistej.
Wyobraźmy sobie naukowca mierzącego długość dżdżownicy za pomocą suwmiarki. Niekonsekwencja naukowca w prawidłowym odczytaniu wagi, lub ciągły ruch ciała dżdżownicy podczas pomiaru, może skutkować nieprawidłowymi pomiarami długości.
Błędu losowego nie da się uniknąć, jednak można go uśrednić za pomocą powtarzających się prób.
Błędy systematyczne są wynikiem uporczywego problemu i prowadzą do stałej rozbieżności w pomiarach. Błędy te są zwykle albo zbyt wysokie, albo zbyt niskie w porównaniu z rzeczywistą wartością. Na przykład masy mierzone za pomocą nieprawidłowo skalibrowanej wagi.
Są one przewidywalne i w większości związane z instrumentami. Jednak w przeciwieństwie do błędu losowego, nie można go uśrednić przy wielokrotnym pomiarze.

błędy losowe i systematyczne

Naukowcy zawsze starają się rejestrować pomiary z najwyższą dokładnością i precyzją. Czasami jednak zdarzają się błędy. Błędy te mogą mieć charakter przypadkowy lub systematyczny. Błędy losowe są obserwowane ze względu na niespójność lub wahania w procesie pomiarowym lub różnice w samej mierzonej wielkości. Błędy te wahają się od większych lub mniejszych od wartości prawdziwej w powtarzanych pomiarach. Wyobraźmy sobie naukowca mierzącego długość dżdżownicy za pomocą linijki. Losowy błąd w tym procesie pomiarowym może wynikać z niespójnej metody odczytu wagi przez naukowca lub z ruchu dżdżownicy. Nie da się uniknąć błędu losowego; jednakże można go uśrednić w powtarzanych próbach.

Błędy systematyczne wynikają z utrzymującego się problemu i skutkują stałą rozbieżnością w pomiarach. Błędy te są zwykle albo większe, albo mniejsze od wartości prawdziwej. Są one przewidywalne i mają przeważnie charakter instrumentalny. Na przykład niewłaściwie skalibrowana waga może stale ważyć przedmioty cięższe niż ich rzeczywista wartość. W przeciwieństwie do błędu losowego, błędów systemowych nie można uśrednić w przypadku powtarzanych pomiarów.

Ten tekst jest adaptacją <a href="https://openstax.org/books/chemistry-2e/pages/1-5-measurement-uncertainty-accuracy-and-precision">Openstax, Chemistry 2e, sekcja 1.5: Niepewność pomiaru, dokładność i precyzja.</a>

Błędy losowe i systematyczne

Naukowcy zawsze dokładają wszelkich starań, aby rejestrować pomiary z najwyższą dokładnością i precyzją. Czasami jednak zdarzają się błędy. Te błędy mogą być ...

Education

JoVE Core

Physics

Fizyka

Unit 1

Jednostka 1

Units, Dimensions, and Measurements

Jednostki, wymiary i pomiary

KEY TERMS AND CONCEPTS

Kluczowe terminy i pojęcia

how measurement errors affect results

Measurement errors can change how accurate and precise a result appears. Scientists try to record measurements as carefully as possible, but errors can still happen. These errors are usually random or systematic.

Random errors come from inconsistency or fluctuation in the measuring process. They can also come from changes in the quantity being measured. In repeated measurements, random error may make a value appear greater than the true value one time and less than it the next.

A simple example is measuring the length of an earthworm with a ruler. The error could come from reading the scale differently each time. It could also happen if the earthworm moves during the measurement. Random error cannot be avoided, but repeated trials can help average it out.

Systematic errors come from a persistent problem that causes a steady measurement shift. They usually make results consistently greater than the true value or consistently less than it. These errors are predictable and are often instrumental in nature.

An improperly calibrated weighing balance is one example of systematic error. It may keep weighing objects heavier than they really are. Unlike random error, systematic error cannot be averaged out by repeating the measurement.

How Measurement Errors Affect Results

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random and systematic errors

Measurement errors can change how accurate and precise a result appears. Scientists try to record measurements as carefully as possible, but errors can still happen. These errors are usually random or systematic. Random errors come from inconsistency or fluctuation in the measuring process. They can also come from changes in the quantity being measured. In repeated measurements, random error may make a value appear greater than the true value one time and less than it the next. A simple...

rules for significant figures

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key terms and concepts

Learn how random and systematic errors affect scientific measurements, with clear examples like a moving earthworm and an uncalibrated balance.

How Measurement Errors Affect Results | JoVE K12

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SC.912.N.1.1

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SC.912.N.1.5.

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SC.912.N.1.7

How Measurement Errors Affect Results

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