Validity, Reliability, Precision, Accuracy Flashcards
What is a methodology?
A methodology is a step-by-step procedure
What is validity? How can you ensure it in an experiment?
The validity of an experiment assesses if the hypothesis follows the overall purpose of the investigation/experiment.
To ensure validity, there must always be:
- An Independent Variable
- A Dependent Variable
- A Controlled Variable
What is reliability? How can you ensure reliability?
Reliability refers to whether the experiment was repeated multiple times.
To ensure reliability, you need to ensure whether the results were consistent and that there was sufficient replication of the experiment to minimise error.
Why does repeating an experiment multiple times make it reliable?
Repeating the experiment on and on at least three times helps minimise error and ensures that there were no mistakes or faults within the experiment
What is accuracy?
Accuracy refers to the ability of one to obtain the MOST ACCEPTED AND CORRECT MEASUREMENT.
It is how close the result is to the official value/measurement that other scientists have agreed upon
What is Precision? What is the difference between accuracy and precision?
Precision is the ability to consistently obtain the same measurement.
The difference between accuracy and precision is that accuracy relies on the instruments used to measure the independent/dependent variables. It focuses on human error and the technique of measuring something. Accuracy is defined by how close it is to the officially accepted answer. However, precision is an assessment of how close your results were towards each other. High precision means that your results were very close apart and consistent, but that does not ensure that the experiment was accurate.
It could have had high precision but low accuracy, due to a wrong method for example, thus affecting the value from the official measurement.
Is precision a part of reliability? What about accuracy?
Precision refers to the reliability of an experiment
Accuracy is how close your measurements/results were to the official, accepted value. Thus, accuracy refers to the validity of an experiment.
What are the three main types of errors in science?
Systematic Error
Random Error
Mistakes
What is a systematic error?
A systematic error is an error that is consistent, which means it can happen again if the investigations are repeated in the same way.
Examples of systematic errors are usually the result of instruments that are not correctly calibrated
What is a random error?
A random error could be a result of when a controlled variable is not kept constant, or when the experiment is just generally unpredictable. A random error can also be considered to be a human error.
How can errors be reduced?
- Use appropriate equipment (Ensure they are calibrated)
- Correct use of the equipment
- Repeat the investigation multiple times (Precision and reliability)
- Using information from secondary sources
