Practice Calibration

Use this after attempting independent practice. These are calibration notes for the new cases, not answers to every original open-ended project. The module assessment retains its own scoring and evidence requirements.

Prerequisite calibration

Its actual service/burst time; turnaround 5 alone does not determine waiting. Repair units and state timelines rather than guess a scheduler policy.

A ready answer includes the example or trace requested in the entry check. A memorized term is not sufficient. Repair the named earlier skill, then change the example and explain it without this page.

Case A

FCFS completion 4/5, turnaround 4/4, waiting 0/3. SRT runs first 0–1, second 1–2, first 2–5; completion 5/2, turnaround 5/1, waiting 1/0. Explicitly name tie/event policy.

Full practice credit requires the result, assumptions and an explanation of the tempting error. A correctly guessed conclusion without those elements is only partial evidence.

Case B

Preemption adds work not present in the zero-cost trace. Recompute using a specified switching rule; do not reuse zero-cost numbers unchanged.

The key judgment is which guarantee survives the changed condition. Do not transfer a result from the first case without checking that condition.

Experiment calibration

Run the supplied scheduling simulator and compare with one actual owned-process observation. Model output is not a measurement of the OS scheduler; record policy/version and avoid assigning causality to one timing sample.

A usable record links the hypothesis to the actual input, observation and interpretation. The negative control must fail for the intended reason, and the repaired setup must pass the relevant check again. Report unexpected outcomes rather than altering the hypothesis afterward. Explicitly state the model, environment and untested boundary; passing a small fixture never proves every deployment behavior.

Recheck

Explain a fresh variant without the key. Retain the original error, repair, help received and delayed result in the existing evidence packet. Self-calibration is not an independent reviewer sign-off or a learner-pilot result. For retrieval-question explanations, use quiz calibration only after attempting the quiz.