Description
Subtract down step for correct or add up step otherwise, then clamp nextLevel to bounds.
A stimulus model relates a chosen level to a supplied response curve, geometry or adaptive rule. One inverse curve or staircase step can be computed without fitting observations, measuring perception or establishing an individual's threshold.
Subtract down step for correct or add up step otherwise, then clamp nextLevel to bounds.
When to use this tool
Use Staircase One Up Down Step Response when you need the stated stimulus-model or adaptive-step calculation.
How to use the tool and how it works
- Enter level, correct, stepUp, stepDown, minimum, maximum. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read unbounded, nextLevel. Use the output convention below.
Require positive up/down steps, ordered min/max and level inside them. Subtract down step for correct or add up step otherwise, then clamp nextLevel to bounds.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| level | Level | Required. Finite number. |
| correct | Correct | Required. Boolean. |
| stepUp | Step Up | Required. Finite number; strictly above 0. |
| stepDown | Step Down | Required. Finite number; strictly above 0. |
| minimum | Minimum | Required. Finite number. |
| maximum | Maximum | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| unbounded | Unbounded | Required. Finite number. |
| nextLevel | Next Level | Required. Finite number. |
{
"input": {
"level": 5,
"correct": true,
"stepUp": 2,
"stepDown": 1,
"minimum": 0,
"maximum": 10
},
"output": {
"unbounded": 4,
"nextLevel": 4
}
}Limitations and assumptions
- This is one response-contingent staircase update. It does not estimate a threshold, track reversals or establish the convergence of a full adaptive procedure.
- 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. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Fit and validate the appropriate model on the study data when estimating a threshold. Review lapse/guess assumptions, calibration, convergence, uncertainty and participant context.
References
Similar or alternative tools
- Psychometric Threshold Supplied Curve Inverse
Return location+scale×ln((target-guess)/(1-lapse-target)).
- Psychometric Lapse Guess Asymptote Gap
Return guess and 1-lapse asymptotes and guess+(1-guess-lapse)×latent.