Simple Slope at +/-1 SD Calculator
Specified linear interaction simple slopes at actual mode rat or mean±SD, centering/coefficient units independently matched. No standard error, causal effect or significance test.
Description
A linear interaction model has a predictor slope that depends on moderator value.
A linear interaction model has a predictor slope that depends on moderator value.1
Evaluating the moderator mean plus and minus one standard deviation gives two conditional slopes. The calculation and input requirements are explained below.
When to use Simple Slope at +/-1 SD Calculator
Enter finite predictor and interaction coefficients, finite moderator mean and nonnegative moderator SD.
How to use Simple Slope at +/-1 SD Calculator and how it works
- Prepare the measurements or independently established model inputs described below, with matching units and observation scope.
- Enter the required fields and run Simple Slope at +/-1 SD Calculator.
- Read the result fields using the formula, output units, signs and ordering explained below.
- Correct any rejected inputs and rerun; interpret the result within the stated model and its assumptions.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| actualPredictorCoefficient | Actual Predictor Coefficient. Use the units and matching context stated in the calculation below. | number | Required; finite; other constraints below |
| actualInteractionCoefficient | Actual Interaction Coefficient. Use the units and matching context stated in the calculation below. | number | Required; finite; other constraints below |
| callerModeratorMean | Caller Moderator Mean. Use the units and matching context stated in the calculation below. | number | Required; finite; other constraints below |
| callerModeratorSd | Caller Moderator Sd. Use the units and matching context stated in the calculation below. | number | Required; nonnegative; finite; other constraints below |
Enter finite predictor and interaction coefficients, finite moderator mean and nonnegative moderator SD. Evaluate predictor coefficient plus interaction times mean+SD and mean-SD, preserving signs. No uncertainty or significance test is computed.
slopePlus=b1+b3*(mean+SD); slopeMinus=b1+b3*(mean-SD) Apply the input ordering, units and branch conditions stated above.
| Output field | Meaning | Value type |
|---|---|---|
| result | Object containing the calculated or selected fields below. | object |
| result.conditionalSlopeAtPlusOneSd | Conditional Slope At Plus One Sd. Interpret its unit, sign, order or availability flag as explained above. | number |
| result.conditionalSlopeAtMinusOneSd | Conditional Slope At Minus One Sd. Interpret its unit, sign, order or availability flag as explained above. | number |
{
"input": {
"actualPredictorCoefficient": 2,
"actualInteractionCoefficient": 3,
"callerModeratorMean": 1,
"callerModeratorSd": 2
},
"output": {
"result": {
"conditionalSlopeAtPlusOneSd": 11,
"conditionalSlopeAtMinusOneSd": -1
}
}
}Limitations and assumptions
The calculation uses the supplied observations and model inputs. It does not collect measurements, select a reference population or coefficient, or establish that the model applies to the actual case. The stated branch conditions and output units remain part of the result.
All fields require explicit values. Unexpected fields, wrong types, nonfinite numbers and sparse arrays are rejected. Alignment, bounds and supported-token rules are explained above; extremely large inputs or nonfinite results can also fail. Input errors differ from successful false comparisons, unavailable-domain flags and empty match lists.
Alternative or Complementary methods
Use Sobel Test Z Mediation Calculator for a complementary operation: The Sobel statistic uses a first-order variance approximation for a product of paths.
Use Mediation Indirect Effect a*b Calculator for a complementary operation: A linear mediation product multiplies two compatible path coefficients.
References
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Simple Slope at +/-1 SD Calculator — tool.io
Similar or alternative tools
- Sobel Test Z Mediation Calculator
The Sobel statistic uses a first-order variance approximation for a product of paths.
- Mediation Indirect Effect a*b Calculator
A linear mediation product multiplies two compatible path coefficients.