Definition
Reliability
Reliability is how consistently a measure, method, or data source gives repeatable results.
Continue from this idea into connected AXIO math.
Repeat it the same way: reliable results stay close.
Boundary: One result cannot show repeatability by itself, and repeated agreement does not guarantee validity.
What it means
Reliable results behave steadily. Repeat the same measurement in the same way, and the answers should be close; ask another trained person, and their result should also agree. A tool can repeat the same mistake, so reliability is about consistency, not truth.
Remember it
Repeat it the same way: reliable results stay close.
Example
A table is measured three times with the same ruler: 119.8 cm, 119.9 cm, and 119.8 cm. The close readings support reliability, although a faulty ruler could still make all three inaccurate.
Watch for
One result cannot show repeatability by itself, and repeated agreement does not guarantee validity.
Common mix-up
Reliable means consistent; valid means suitable for the intended question or measurement.
Exact meaning
Reliability describes the consistency of results when a measurement or method is repeated under suitably similar conditions, or when different raters use the same agreed method. Consistency alone does not show that the result measures the intended thing correctly.