Cherry Picked Start Date Trend Splice Warning Checker

Audit actual selected trend window versus full observed series OLS slope with signed difference and opposition witness; no causal inference, automatic cherry-picking intent diagnosis, seasonality adjustment or guarantee full window is appropriate.

Description

Selected and full-window trends can differ in sign.

Selected and full-window trends can differ in sign. Comparing fitted slopes exposes that evidence without determining motive.^[1]

Enter at least two aligned finite values/nonnegative strictly increasing times and inclusive integer start/end indices enclosing at least two points. Fit intercept-bearing OLS for both windows; return slopes/difference/opposition.

When to use Cherry Picked Start Date Trend Splice Warning Checker

Use Cherry Picked Start Date Trend Splice Warning Checker when you need to evaluate the supplied records under the calculation and evidence rules below. No seasonality, causal claim, cherry-picking intent or preferred observation window is inferred.

Prepare the actual editorial, source, layout, timing or audience records requested. Supply explicit house-policy limits and preserve missing evidence.

How to use Cherry Picked Start Date Trend Splice Warning Checker and understand its results

Prepare the actual editorial, source, layout, timing or audience records requested. Supply explicit house-policy limits and preserve missing evidence.
Enter observationTimes, observedValues, callerSelectedStartIndex, callerSelectedEndIndex using the field table and calculation rules, then run the tool.
Read fullSeriesLinearSlope, selectedWindowLinearSlope, signedSelectedMinusFullSlope, opposedSlopeSigns. 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
observationTimes	Observation times	list of number	Required
observedValues	Observed values	list of number	Required
callerSelectedStartIndex	Caller selected start index	number	Required
callerSelectedEndIndex	Caller selected end index	number	Required

difference=selectedOLSSlope−fullOLSSlope; opposed=both nonzero with opposite signs

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
fullSeriesLinearSlope	Full series linear slope	number
selectedWindowLinearSlope	Selected window linear slope	number
signedSelectedMinusFullSlope	Signed selected minus full slope	number
opposedSlopeSigns	Opposed slope signs	boolean

json

{
  "input": {
    "observationTimes": [
      0,
      1,
      2,
      3
    ],
    "observedValues": [
      0,
      10,
      10,
      0
    ],
    "callerSelectedStartIndex": 0,
    "callerSelectedEndIndex": 1
  },
  "output": {
    "fullSeriesLinearSlope": 0,
    "selectedWindowLinearSlope": 10,
    "signedSelectedMinusFullSlope": 10,
    "opposedSlopeSigns": false
  }
}

Limitations and assumptions

No seasonality, causal claim, cherry-picking intent or preferred observation window is inferred.

Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Numeric lists are limited to 10,000 entries; string lists to 128 strings of at most 128 characters each. The rules above may impose smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors. A successfully returned false flag is an evaluated outcome; its meaning is explained above.

Alternative or Complementary methods

Use Chart Axis Zero Truncated Bar Misleading Checker: A truncated bar axis changes apparent lengths relative to zero-based values. Out-of-range bars should remain visible. For a complementary task, use Statistic Staleness Years Old Data Flag Checker: Statistic age should use its reference date rather than its publication date. Future dates need a separate flag.

References

Cherry Picked Start Date Trend Splice Warning Checker — tool.io

Similar or alternative tools

Chart Axis Zero Truncated Bar Misleading Checker
A truncated bar axis changes apparent lengths relative to zero-based values. Out-of-range bars should remain visible.
Statistic Staleness Years Old Data Flag Checker
Statistic age should use its reference date rather than its publication date. Future dates need a separate flag.