A measurement becomes much more powerful when you can return to it.
Record the baseline.
Change the input.
Repeat the task.
Measure again.
Compare.
That is the purpose of a retest.
What is a retest?
A retest repeats relevant parts of an earlier assessment so the recorded responses can be compared.
The closer the relevant testing conditions are, the more meaningful the comparison can become.
The goal is not to reproduce every variable perfectly.
It is to create a sufficiently controlled comparison to ask:
What changed?
Why one measurement is not enough
A single measurement describes a moment.
It does not show direction of change.
Once a baseline and retest exist, comparison becomes possible.
Did pressure distribution change?
Did timing change?
Did the sequence change?
Did the response become more repeatable?
Did the athlete report a different experience?
Those questions require at least two points of reference.
Change the input
Between baseline and retest, something changes.
That input might relate to the assessment or calibration process, task instruction, movement condition or another defined variable relevant to the athlete.
The important principle is that the change should be deliberate enough that the subsequent response can be meaningfully compared.
Repeat the Measurement
A retest repeats the relevant parts of the original assessment under comparable conditions.
The recorded measures return — pressure, distribution, angle, timing, sequence, repeatability, loading and movement response — whichever were relevant to the question being tested.
The measurement is repeated. It is not assumed.
Compare What Changed
Comparison does not begin by declaring that the second result must be better.
First establish whether it is different.
Then examine:
- direction of change
- magnitude of change
- repeatability
- athlete feedback
- task context
- relevance to the performance objective
This prevents the data from being forced into a predetermined conclusion.
What if nothing changes?
No measurable change is still a result.
It may mean the input did not materially alter the recorded response under those conditions.
That information can prevent unnecessary assumptions and inform what is tested next.
Measurement is useful because it can challenge an expectation as well as support one.
Retest is where calibration becomes visible
Calibration is not simply making a change.
The important part is checking the response after the change.
That creates the I AM 900 loop:
MEASURE → CALIBRATE → RETEST
And operationally:
BASELINE → MEASURE → CHANGE THE INPUT → RETEST → COMPARE WHAT CHANGED
Build the athlete's own record
Over time, repeated baseline and retest comparisons can create a clearer record of how that athlete responds under defined testing conditions.
The athlete becomes their own reference.
That is more useful than assuming every athlete should produce an identical response.
Do not stop at:
"We changed something."
Ask the stronger question:
"What changed when we measured it again?"
That is the purpose of retesting.
