Parametric nature

Option	Description
Parametric	All functional relationships are specified by a finite set of parameters.
Semi-parametric	Combines parametric and non‑parametric elements.
Non-parametric	No fixed form, often data‑driven.
Rule-based	Deterministic rules define relationships.

Definition

The level of assumed functional specification in the method’s core structure.

Explanation

Parametric methods impose strong structural assumptions that simplify estimation but risk misspecification, while non‑parametric approaches adapt to data but require larger sample sizes. Semi‑parametric methods strike a compromise by combining parametric core components with flexible adjustments.

Tools/rationale for helping assessment

1. Think whether you trust a specific functional form (e.g. logistic growth) or need flexibility depending on your system’s knowledge.
2. If theory prescribes a form, Parametric; if you want a mixture, Semi-parametric; if you want entirely data‐driven, Non-parametric; if you want to set decision rules, Rule-based.

Example

Population growth is known logistic from past studies → Parametric. If you combine logistic with spline corrections, Semi-parametric. If you choose a random forest, Non-parametric. If you use an expert‐system of rules (“if NDVI>0.7 then high habitat”), Rule-based.