Confidence Interval on Stratigraphic Range Strauss-Sadler
Calculate one-sided Strauss–Sadler endpoint extension assuming independent uniform recovery over the true stratigraphic range; not simultaneous two-endpoint coverage or corrected for heterogeneous collecting.
Description
Observed range endpoints underestimate true endpoints under incomplete recovery.
Observed range endpoints underestimate true endpoints under incomplete recovery. Strauss–Sadler extension uses a uniform independent-recovery assumption.1
Calculate one-sided Strauss–Sadler endpoint extension assuming independent uniform recovery over the true stratigraphic range; not simultaneous two-endpoint coverage or corrected for heterogeneous collecting.
When to use Confidence Interval on Stratigraphic Range Strauss-Sadler
Use this tool to calculate one-sided Strauss–Sadler endpoint extension assuming independent uniform recovery over the true stratigraphic range; not simultaneous two-endpoint coverage or corrected for heterogeneous collecting.
Prepare the fossil measurements or occurrence records and the chosen calibration parameters. Retain the stated coordinate, age and measurement conventions.
How to use Confidence Interval on Stratigraphic Range Strauss-Sadler and understand its results
- Prepare the fossil measurements or occurrence records and the chosen calibration parameters. Retain the stated coordinate, age and measurement conventions.
- Enter independentOccurrencePositionsM, oneSidedConfidence using the field table and calculation rules, then run the tool.
- Read straussSadlerOneSidedExtensionM, upperTrueRangeEndpointM. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| independentOccurrencePositionsM | Independent occurrence positions m | list of number | Required |
| oneSidedConfidence | One sided confidence | number | Required |
Use at least two distinct independently sampled positions and confidence in (0,1). Find the observed span, calculate the stable extension and add it to the upper observed endpoint.2
extension = observed span × [(1 − confidence)^(−1/(n−1)) − 1] Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| straussSadlerOneSidedExtensionM | Strauss sadler one sided extension m | number |
| upperTrueRangeEndpointM | Upper true range endpoint m | number |
{
"input": {
"independentOccurrencePositionsM": [
0,
5,
10
],
"oneSidedConfidence": 0.75
},
"output": {
"straussSadlerOneSidedExtensionM": 10,
"upperTrueRangeEndpointM": 20
}
}Limitations and assumptions
One-sided coverage is not simultaneous coverage of both endpoints; heterogeneous collecting violates the model.
Numbers and computed results must be finite; overflow produces an error. Numeric lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Signor-Lipps Effect Back-Extension Estimate: Model a Signor–Lipps unobserved tail under stationary independent Poisson recovery using caller rate exposure/detection; fitted rate uncertainty and correlated sampling are excluded, not a confirmed extinction date. For a complementary task, use Stratigraphic Range Extent: Summarize observed section-position span and endpoint measurement uncertainty, not true taxon duration; positions share a caller increasing chronological/section convention.
Further background: Estimating time of origin from fossil occurrences.
References
-
Estimating time of origin from fossil occurrences — Palaeontologia Electronica
-
Confidence Interval on Stratigraphic Range Strauss-Sadler — tool.io
Similar or alternative tools
- Signor-Lipps Effect Back-Extension Estimate
Model a Signor–Lipps unobserved tail under stationary independent Poisson recovery using caller rate exposure/detection; fitted rate uncertainty and correlated sampling are excluded, not a confirmed extinction date.
- Stratigraphic Range Extent
Summarize observed section-position span and endpoint measurement uncertainty, not true taxon duration; positions share a caller increasing chronological/section convention.