Description
Display-rounding uncertainty under an explicit uniform quantization model combined with independent supplied repeatability, not a device acceptance standard.
Pediatric research records use chronological age, visit windows, measurement resolution, task observations, and caregiver reports. Missing observation differs from noncompletion, and a completeness share depends on its denominator. Arithmetic on supplied records is separate from a developmental or clinical assessment.
Display-rounding uncertainty under an explicit uniform quantization model combined with independent supplied repeatability, not a device acceptance standard.
When to use this tool
Use Pediatric Device Resolution Halfwidth when you need this age, observation, visit, measurement, or record-completeness calculation with supplied inputs.
How to use the tool and how it works
- Enter displayIncrement, conversionScale, repeatabilitySd. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read roundingHalfWidth, roundingSd, combinedStandard. Use the output convention below.
For nonnegative displayIncrement and repeatabilitySd return roundingHalfWidth=displayIncrement*abs(conversionScale)/2, roundingSd=displayIncrement*abs(conversionScale)/sqrt(12), and combinedStandard=hypot(roundingSd,repeatabilitySd).1
A uniform interval with halfwidth a has standard uncertainty a/sqrt(3). With a full rounding increment d this gives d/sqrt(12), under the stated uniform-rounding assumption.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| displayIncrement | Display Increment | Required. Finite number; minimum 0. |
| conversionScale | Signed source-to-target length factor; magnitude used for uncertainty. | Required. Finite number. |
| repeatabilitySd | Nonnegative standard deviation already in converted units. | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| roundingHalfWidth | Rounding Half Width | Required. Finite number. |
| roundingSd | Rounding Sd | Required. Finite number. |
| combinedStandard | Combined Standard | Required. Finite number. |
{
"input": {
"displayIncrement": 0.2,
"conversionScale": 1,
"repeatabilitySd": 0
},
"output": {
"roundingHalfWidth": 0.1,
"roundingSd": 0.05773502691896258,
"combinedStandard": 0.05773502691896258
}
}Limitations and assumptions
- RepeatabilitySd must already use the converted output unit. The standard-uncertainty combination assumes a uniform rounding interval and independent components; no device validation or clinical decision threshold is supplied.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Signed zero is exported as zero.
Alternative or Complementary methods
Use verified dates, measurement protocols, and observation definitions for the intended research question. A clinical interpretation needs the relevant age-specific assessment and context beyond the arithmetic record check.
References
-
Calculation and input contract: pediatrics/pediatric-device-resolution-halfwidth — tool.io
-
Evaluating uncertainty components: Type B — National Institute of Standards and Technology
Similar or alternative tools
- Pediatric Measurement Repeat Range Term
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- Tissue Margin Measurement Uncertainty Term
Independent standard-uncertainty quadrature and supplied coverage factor, without a margin-status or clinical interpretation.