# Assessment Instructions: Problem Set 05 — Hyades Cluster Structure and Dynamical Timescales

## Inputs to Inspect
Student submission, this problem set, the solution key, the corresponding lecture slides/notes, and the referenced dataset(s) under `materials/ASTR330/data/`.

## Grading Standard
Award credit for correct method and units first, then for the specific numeric result. A student who shows correct reasoning with a small arithmetic slip should receive most of the available credit; a student with a correct-looking number but no visible derivation steps should not. Because this is a 300-level quantitative course exceeding ASTR 310's own rigor, full marks require a genuine derivation (not just formula substitution) wherever the problem set asks for one.

## Problem-Level Criteria
- Problem 1: 20 points — correct volume and density arithmetic.
- Problem 2: 15 points — correct half-mass density arithmetic and comparison.
- Problem 3: 15 points — correct opacity-metallicity-lifetime reasoning chain.
- Problem 4: 20 points — correct identification of the primary versus secondary cause of the age discrepancy.

## Resubmission Policy
Students may resubmit within one week of receiving feedback. A resubmission must show a corrected derivation, not only a corrected final number, and should reference the specific feedback comment it addresses. Regrade to a maximum of 90% of the original point value unless the error was a grading mistake.

## Common Errors to Flag
- Forgetting the 4/3πr³ volume formula or mis-cubing the radius.
- Reversing the direction of the metallicity-opacity-lifetime relationship in Problem 3.
- Conflating the metallicity effect (Problem 3, secondary) with the fixed-exponent effect (Problem 4, primary cause) as if they were the same explanation.