Question

Having trouble distuguishing between reliability, validity, objectivity and accuracy

Reliability states that the test will produce the same results on Tuesday morning as the will on Thursday morning, correct?

And accuracy results will be the same regardless of who administers the test?

Answer 1

Let me first define all these 4 variables and then we will discuss the statement you have mentioned.

Reliability - As the name suggests, it is a measure of how dependably an observation is exactly the same when repeated. It refers to the measuring procedure rather than to attribute being measured.

Validity - Simply put, it is the extent to which the study measures what it is intended to measure.

Objectivity - It is the degree and how close to which more than one person can measure a test.

Accuracy - It is the degree to which a measurement represents the true value of something.

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So, the statement that 'The test will produce the same results on Tuesday morning as it will on Thursday morning' is claiming the observation to be repeated. So, definitely its measure of reliability.

And if the results will be same regardless of who administers the test, we would be measuring objectivity and not accuracy. This is because objectivity gives us the measure of how close two values are measured irrespective of person who measures it.

Note that accuracy is a parameter of one measurement. It measures how close your data is to an already specified value. But Objectivity is the measure of how close your two observations are.

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