Drawn from a supplied community health scenario, the HI520 Unit 2 diagram shows eight entities, cardinality and optionality on every line, and a narrative reading each relationship both ways. Searches like "hi 520 unit 2 assignment example", "hi520 unit 2 sample" and "hi520 unit 2 example" land here.
What a finished HI520 Unit 2 entity relationship diagram looks like
A single-page diagram in Information Engineering notation, followed by two pages of prose. The boxes are PATIENT, SITE, PROVIDER, ENCOUNTER, DIAGNOSIS CODE, ENCOUNTER DIAGNOSIS, LAB ORDER and LAB RESULT, each listing attributes with the identifier marked PK and any borrowed identifier marked FK. ENCOUNTER DIAGNOSIS resolves the many-to-many link between visits and codes and carries a sequence attribute, so a principal diagnosis can be told from a secondary one. LAB RESULT hangs from LAB ORDER on a zero-to-many line, because an order can be canceled before any specimen exists. DIAGNOSIS CODE has a dashed border and a label calling it reference data loaded from an external code set rather than typed by staff. A symbol legend sits under the diagram, and a numbered list of seven assumptions precedes the narrative.
How a HI520 Unit 2 example is structured
The narrative walks the diagram in the order a patient meets the organization: registration, an encounter at a site, the diagnoses recorded there, orders placed, results returned. Each relationship gets a pair of sentences, one per direction, with the minimum stated as well as the maximum, since optionality is where health scenarios hide their rules. A patient may exist with zero encounters, for example, because registration can precede the first visit. Attribute placement is argued wherever it is not obvious: the ordering provider sits on LAB ORDER rather than on ENCOUNTER, because a covering physician can order during another clinician's visit. The assumptions list sits between diagram and prose so each one can be cited by number. The last paragraph lists two scenario questions the model can already answer and one it cannot, insurance coverage, flagged for a later revision.
Eight boxes, keys marked
Every entity lists its attributes with PK and FK labels, and the reference entity for diagnosis codes is visually set apart from the tables staff will populate.
An associative entity with a sequence
ENCOUNTER DIAGNOSIS sits between visits and codes, and its sequence number separates the principal diagnosis from the secondary ones a later query will need.
Optional ends read aloud
Zero-to-many lines from patient to encounter and from order to result are each defended with an event from the scenario that produces the zero.
Seven numbered assumptions
Gaps in the scenario, such as whether one encounter can span two sites, are closed with a stated assumption that the narrative then cites by number.
A question the model cannot answer yet
Insurance coverage is named as outside the current diagram, with a sentence on which entity and which relationship it would add when the scope grows.
Where marks go in HI520 Unit 2
Cardinality is what graders test first on a health ERD, and bare lines forfeit that row before any other reading. Minimums are the subtler gap: a line marked one-to-many that never says whether zero is allowed hides whether a registered patient with no visits can exist. Many-to-many relationships left unresolved between encounters and diagnoses are the common structural miss, often paired with a single diagnosis column on the encounter that cannot hold a second condition. Code sets drawn as though staff typed them lose accuracy credit. Attributes placed on the wrong entity, an ordering provider stored on the visit, draw comments under most rubrics. Diagrams copied from a textbook hospital example, with entities the supplied scenario never mentions, are scored as not derived from the case. Mixed notation within one diagram costs points as well.
Get a HI520 Unit 2 example written to your instructions
Scenarios for this diagram vary widely by HI520 section, from a hospital pharmacy to a public health registry. Share the scenario text exactly as given, the Unit 2 rubric and any notation or drawing tool the instructions name. A sample diagram and narrative are built on that case in 24-48h, and the first custom sample is free.
HI520 Unit 2 questions, answered
Should reference code sets appear as entities in the diagram?
Usually yes, drawn as lookup entities that other tables point to. A diagnosis code table lets each encounter diagnosis reference a valid value instead of free text, and it makes the code set version visible as an attribute. Some instructors prefer them omitted for simplicity, so check whether your prompt limits the diagram to entities that staff populate.
What is the difference between cardinality and optionality?
Cardinality is the maximum at each end of a relationship, one or many. Optionality is the minimum, zero or one, and says whether the relationship must exist at all. A lab order with zero-to-many results tells a reader that an order can exist before, or without, any result, which a line showing only one-to-many would leave ambiguous.
Can the ERD include attributes I am not sure about yet?
It can, provided each uncertain choice is recorded as an assumption rather than left silent. Graders generally accept a reasonable reading of an unclear scenario when the reasoning is written down. The sample numbers its assumptions and refers to them in the narrative, making plain which parts of the diagram rest on interpretation.