Taking a wide lab-result export to third normal form, HI520's Unit 3 exercise states every functional dependency first and shows which split removed which anomaly. Searches like "hi 520 unit 3 assignment example", "hi520 unit 3 sample" and "hi520 unit 3 example" land here.
What a finished HI520 Unit 3 normalization exercise looks like
Five pages in relational notation. Fifteen attributes make up the opening relation: MRN, patient name, birth date, site name, site address, provider name, provider identifier, order number, order date, test name, local test code, result value, units, collection time and a diagnosis list reading [dx-1]; [dx-2]; [dx-3]. A dependency list follows in arrow form, MRN determining name and birth date, local test code determining test name and units, eleven lines in all. The first normal form section moves the diagnosis list into its own relation keyed on order number and code. The second removes attributes that depend on only part of the composite key of order number and test code. The third lifts patient details and site address out along their chains. The resulting relations are listed with keys underlined, and a two-column anomaly table follows.
How a HI520 Unit 3 example is structured
Every dependency is listed before the relation it affects is touched, so no split appears without a stated reason. Each normal form section follows the same order: the rule in one sentence, the attributes that break it, the decomposition, and a join test showing the pieces reassemble to the original rows without inventing any. First normal form handles the semicolon list, since no query can count patients by a condition buried inside a string. Second normal form separates facts about the order from facts about the test, because the composite key of order number and test code makes partial dependency possible. Third normal form removes the chains that run through a non-key attribute, patient details through MRN and the address through the site. The closing anomaly table pairs each split with the update, insert or delete problem it prevents in this particular data.
The export as received
Fifteen attributes in one relation, with the semicolon diagnosis cell and the repeated clinic address marked as the two features that trigger every later step.
Eleven dependencies in arrow form
Each line names a determinant and what it fixes, including the test code that determines units, so every decomposition can be checked against a stated rule.
Three normal forms, one pattern
Rule, violation and split are repeated for first, second and third normal form, and each section closes with a join test on the shared key.
A derived column dropped
Patient age, present in the export, is removed rather than normalized, because it can be computed from birth date and collection time and would otherwise go stale.
Anomalies each split prevents
A two-column table ties every decomposition to a concrete failure, such as a clinic move that would demand hundreds of address edits in the flat file.
Where marks go in HI520 Unit 3
Graders look first for the dependencies, and an answer that jumps from the flat export to finished tables without listing them gives the rubric nothing to score. Splitting the semicolon diagnosis cell into numbered columns, diagnosis one through three, is a frequent first normal form error, since it spreads the repeating group across columns rather than eliminating it. Partial and transitive dependencies are regularly confused, and claiming a partial dependency in a relation with a single-attribute key shows the definition was memorized rather than applied. Decompositions that drop the shared attribute cannot be joined back, and papers seldom test for that. A derived age kept as a stored column draws a comment in some sections. Stopping short of third normal form without saying so, or overshooting into tables of one attribute, also costs credit.
Get a HI520 Unit 3 example written to your instructions
Where the Unit 3 prompt supplies its own flat table, attach it as delivered, whether a spreadsheet or a relation typed into the instructions, along with the HI520 rubric. Dependencies, each normal form and the join tests are then worked on that table. Delivery is 24-48h, and there is no charge for the first custom sample.
HI520 Unit 3 questions, answered
Does the exercise need to go beyond third normal form?
Most HI520 prompts stop at third normal form, and the sample does too unless instructed otherwise. Boyce-Codd normal form adds a requirement only where an attribute that is not a candidate key determines part of a key, which is uncommon in a small health dataset. If your rubric names BCNF, the sample adds a short section testing each relation against it and records what it found.
Why not keep the diagnosis list as text and parse it in queries?
Because every query that needs a diagnosis would then depend on string handling, and one extra space or a changed separator makes a patient invisible to a count. A separate relation with one row per code lets a query filter with an ordinary equality test and lets the database enforce that each code exists in the reference table.
What is a join test, and do graders expect one?
It checks that the decomposed relations, joined on their shared attributes, reproduce the original rows exactly, with nothing invented. Some rubrics call it lossless decomposition, others leave it implicit. Showing it briefly after each split demonstrates that the design lost nothing, and it catches a missing foreign key before your schema is built on top of it.