A complete model with two parameter values and four sample points

On this page
  1. Goal and scope
  2. Givens and symbols
  3. Rules and sources
  4. Main derivation
  5. Substeps and lemmas
  6. Reverse audits
  7. Error controls and negative controls
  8. Result and limitations
  9. Verification and source binding

← Guide index · Original MKO

derivation-mko-parametric-statistical-model-01 · ocme-new142-reader-adoption-20261021

Goal and scope

Validate every parameter law and distinguish likelihood from posterior.

A complete finite table; no posterior or optimality inference.

Givens and symbols

  • work
  • G1 — Theta={1/4,3/4}, Omega={00,01,10,11}; P_(1/4)=(9,3,3,1)/16 and P_(3/4)=(1,3,3,9)/16.
  • θ — fixed unknown parameter

Rules and sources

  • mko_definition · cited — Validate the finite parameter set and every nonnegative normalized row of the complete law table. In L(theta;x)=P_theta(x), likelihood varies theta while the observation x is fixed. It is not a posterior; without a prior no Bayes update is performed. One observation does not establish identifiability. · mko-parametric-statistical-model
  • work · prerequisite — Finite laws have nonnegative probabilities summing to one; a statistic depends only on data, and expectation sums all weighted outcomes.

Main derivation

S01 · implies

Before

\Theta=\{1/4,3/4\},\quad\Omega=\{00,01,10,11\}

After

P_\theta:\Omega\to[0,1]\quad(\theta\in\Theta)

Conditions: none

Rule: work · Uses: G1, work

Leaf basis: work

Fix the common carrier without deleting samples as theta changes.

S02 · implies

Before

P_{1/4}=(9,3,3,1)/16

After

(9+3+3+1)/16=1

Conditions: none

Rule: work · Uses: G1, S01, work

Leaf basis: work

All four entries of the first row are nonnegative and normalized.

S03 · implies

Before

P_{3/4}=(1,3,3,9)/16

After

(1+3+3+9)/16=1

Conditions: none

Rule: work · Uses: G1, S02, work

Leaf basis: work

Validate the second row explicitly rather than skipping it by appearance.

S04 · implies

Before

x=01\text{ fixed}

After

L(1/4;01)=3/16,\quad L(3/4;01)=3/16

Conditions: none

Rule: mko_definition · Uses: G1, S03, mko_definition

Leaf basis: mko_definition

After fixing the observation, theta is the likelihood's argument.

S05 · implies

Before

\sum_{\theta\in\Theta}L(\theta;01)

After

3/16+3/16=3/8\ne1

Conditions: none

Rule: work · Uses: G1, S04, work

Leaf basis: work

Likelihood values across parameters need not normalize to a probability law.

S06 · implies

Before

x=00

After

L(1/4;00)=9/16>1/16=L(3/4;00)

Conditions: none

Rule: work · Uses: G1, S05, work

Leaf basis: work

Another observation gives different likelihoods for the two parameters.

S07 · implies

Before

P_{1/4}(00)=9/16\ne1/16=P_{3/4}(00)

After

P_{1/4}\ne P_{3/4}

Conditions: none

Rule: work · Uses: G1, S06, work

Leaf basis: work

The model laws are distinct, witnessed by an explicit sample event.

S08 · implies

Before

\theta\mapsto P_\theta\text{ with both rows normalized}

After

\{P_\theta:\theta\in\Theta\}\text{ is a finite parametric model}

Conditions: none

Rule: mko_definition · Uses: G1, S07, mko_definition

Leaf basis: mko_definition

The common carrier and every parameter law qualify the finite model.

Substeps and lemmas

No substeps in this guide.

Reverse audits

  • S08 · premise_audit · G1, S07, mko_definition — No prior was supplied, so no Bayes update is performed.
  • S07 · premise_audit · G1, S06, work — This comparison uses the complete laws, not one observed 01.
  • S06 · premise_audit · G1, S05, work — A larger likelihood is not a computed parameter probability.
  • S05 · premise_audit · G1, S04, work — The sum3/8 explicitly refutes treating likelihood itself as a posterior.
  • S04 · premise_audit · G1, S03, mko_definition — Do not interchange the roles of x and theta.
  • S03 · premise_audit · G1, S02, work — These two rows exhaust the parameter set.
  • S02 · premise_audit · G1, S01, work — The weight9 is not itself probability 9.
  • S01 · premise_audit · G1, work — Both rows require four entries.

Error controls and negative controls

Rowwise

Check both complete denominator 16 rows separately.

Fixed observation

Fix x before traversing every theta for the likelihood table.

  • The posterior at 01 is(3/16,3/16). → reject — Its sum is 3/8, not 1, and no prior is supplied.
  • Each theta may silently use a different carrier. → reject — This model requires the same four-sample carrier.
  • One01 proves the laws identical. → reject — Their00 probabilities differ:9/16 versus1/16.

Result and limitations

The rows define a valid finite parametric model; both L(theta;01) values are 3/16, not a posterior.

    Verification and source binding

    3 declared checks for this guide; only the listed expressions are covered.

    • source commit: b1b2f1dcf8c50d67a93fe52d95f8eef7b3abba9f
    • adopted source SHA-256: d00df7b6f9cdd89591f628108246c88f499ea10b7d1142e3b840f769915b49dc
    • original source SHA-256: fcaef8fae4f87c9c47807672f655dbe899166728be3799d64ec5e07d2e5c74f2
    • Lean: NOT_RUN · independent AI: SCOPED_LEAD_AND_BILINGUAL_CONTEXT_REVIEW

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