| Course | BU 453 Database Management |
|---|---|
| Unit | Unit 3 |
| Paper type | Normalization exercise |
| Length | About 1,030 words, 6 pages |
| Format | APA 7 student paper |
| School | Herzing University |
| Program | BS in Business Analytics |
| Updated | September 2026 |
Free sample paper for BU 453 Unit 3
One 412-Row Spreadsheet, Three Normal Forms and the Anomaly Each Step Removes: A Normalization Exercise for a Composite Boise Music School's Lesson Roster
Student Name
Business, Herzing University
BU 453: Database Management
Instructor Name
February 11, 2026
One 412-Row Spreadsheet, Three Normal Forms and the Anomaly Each Step Removes: A Normalization Exercise for a Composite Boise Music School's Lesson Roster
The Table That Holds Too Much
Harmony Hill Music School, the composite Boise lesson school in this course, runs its business from a single spreadsheet called Lesson Roster. It has 412 rows, one for each student's weekly lesson in the spring 2026 term, and twenty columns: student name and birth date; two sets of guardian name and phone; teacher name, phone and hourly rate; instrument; term; weekday, start time, lesson minutes and room; whether the room has a piano; the lesson price; and, for students renting an instrument, its serial number, type and monthly fee. This exercise decomposes that table one dependency at a time, stating after each step which update, insertion or deletion problem has just become impossible.
Kent (1983) explains the normal forms informally: each non-key fact should depend on the key, the whole key and nothing but the key. The exercise follows that sequence, and the entities it arrives at should match the model built in the first two units, which is itself a check on both pieces of work.
First Normal Form: One Value per Cell, No Repeating Groups
The roster stores guardians as a repeating group: Guardian 1 name and phone, Guardian 2 name and phone. Adults have both pairs empty; one child with three contacts, two parents and a grandparent, has the grandparent written into a notes column. Moving guardians into their own rows, one row per student and guardian pair, removes the repeating group.
What becomes impossible: an insertion anomaly, having nowhere to record a third guardian, and a query anomaly, needing to search two columns to find every child of a given parent. The roster's key at this point is the combination of student, term and instrument, since a student taking two instruments appears twice.
Second Normal Form: No Fact About Part of the Key
With a key of student, term and instrument, several columns depend on only part of it. A student's birth date depends on the student alone, not on the term or instrument. The term's dates depend on the term alone. These partial dependencies are removed by moving student facts into a Student table keyed by student and term facts into a Term table.
What becomes impossible: an update anomaly. In the roster, 31 students take two instruments and so appear twice, each row carrying the birth date. When the office corrected one boy's birth date last fall, it changed one row and not the other, and the two rows now disagree. With birth date stored once in Student, the disagreement cannot arise.
Third Normal Form: No Fact About a Non-Key Column
Four columns depend on another non-key column rather than on the enrollment. Teacher phone and hourly rate depend on the teacher, so they move to a Teacher table. Whether a room has a piano depends on the room, so it moves to a Room table. Lesson price depends on the lesson length and the term, since the school sets one price for each length each term, so it moves to a Rate Card table keyed by term and minutes. And instrument type and monthly fee depend on the serial number, so they move to an Instrument table.
What becomes impossible: three anomalies at once. An update anomaly: one teacher's phone number appears in 26 rows and changed in January; the roster still holds the old number in four. An insertion anomaly: the school hired a cello teacher in February who had no students yet, and there was nowhere to record her rate. A deletion anomaly: when a student who rented a violin stopped lessons, deleting her enrollment row also deleted the only record of that violin's serial number and fee.
The rental itself needs one more separation. In the roster, rental columns sit on the enrollment row, but a rental is between a student and an instrument, not between an enrollment and an instrument; a student taking piano and renting a cello shows why. Rentals move to their own table keyed by instrument and start date, linked to the student.
Checking the Result Against the Model and the Data
The ten tables match the entities in the first two units for everything the roster covers. The roster does not hold billing accounts, invoices, payments, individual lesson outcomes or recitals, which the school keeps in separate documents, so those tables come from the model rather than from this decomposition. Counting the rows in each new table checks that nothing was lost: 380 students, 301 guardians, 342 student and guardian pairings, 14 teachers, 9 rooms, 1 term, 3 rate card rows, 412 enrollments, 120 instruments and 97 current rentals. The 412 enrollments equal the roster's 412 rows, and joining the tables back together reproduces the original roster exactly, apart from the corrected birth date and phone number, which is the evidence that the decomposition lost no information while removing the contradictions.
Where the Decomposition Stops
The result is ten tables: Student, Guardian, Student Guardian, Teacher, Room, Term, Rate Card, Enrollment, Instrument and Rental. Checked against the normal forms, every non-key column in each table depends on its whole key and nothing else. Each table also meets the stricter Boyce-Codd form: in Rate Card, for example, the only determinant of price is the full key of term and minutes.
Two choices deliberately stop short of further decomposition. Instrument taught remains a text value on Enrollment rather than a separate lookup table, because the school needs no facts about instruments as subjects; a misspelling risk is handled by a check constraint in the schema. And a teacher's list of instruments taught remains out of the tables for now, since no process uses it; adding a Teacher Instrument table later would be simple. Leaving a table less decomposed is acceptable when no anomaly follows from it, and Hoffer et al. (2019) note that normalization is a tool for removing specific problems, not a goal in itself. Codd (1970) introduced normalization to protect a database from exactly the inconsistencies found in this spreadsheet. Harmony Hill and its roster are composites written for this course.
References
Codd, E. F. (1970). A relational model of data for large shared data banks. Communications of the ACM, 13(6), 377-387. https://doi.org/10.1145/362384.362685
Hoffer, J. A., Ramesh, V., & Topi, H. (2019). Modern database management (13th ed.). Pearson.
Kent, W. (1983). A simple guide to five normal forms in relational database theory. Communications of the ACM, 26(2), 120-125. https://doi.org/10.1145/358024.358054
Reading the BU 453 Unit 3 instructions
BU 453 Unit 3 asks students to normalize a table step by step. Typical requirements include identifying the starting table's key and dependencies, moving through first, second and third normal form, naming the update, insertion or deletion anomaly each step removes, and presenting the final tables. Many instructors ask how far decomposition must go and whether leaving something denormalized is a mistake; stopping is acceptable when no anomaly results and the reason is stated. Using a department's real spreadsheet is usually discouraged. A step-by-step narrative with before and after structures in APA 7 is typical, and strong submissions check that the decomposed tables still reproduce the original data.
How this BU 453 Unit 3 example is built
The paper opens with the roster's twenty columns and the informal rule for normal forms. The first normal form section moves guardians into their own rows and names two anomalies removed. The second normal form section removes partial dependencies on the composite key, illustrated by a birth date corrected in one row but not another. The third normal form section moves four groups of facts to their own tables and describes three anomalies from the school's records, then separates rentals from enrollments. A checking section compares the result with the model and confirms row counts. The final section confirms Boyce-Codd form and explains two places where decomposition deliberately stops.
Reading the BU 453 Unit 3 rubric
Normalization rubrics at Herzing generally reward correct identification of keys and dependencies, accurate progression through normal forms, clear naming of anomalies, a correct final structure and justified stopping points, together with writing and APA. Key identification earns full credit when the starting key is stated. Progression scores highest when each step removes a specific type of dependency. The anomaly criterion rewards naming the update, insertion or deletion problem each step makes impossible, ideally with an example. The final structure is judged on whether every non-key column depends on the whole key. Stopping points earn points when the student explains why further decomposition is unnecessary rather than stopping silently.
Common BU 453 Unit 3 mistakes, and how to avoid them
Normalization answers often lose points by jumping straight to final tables without showing the steps. Another common problem is naming normal forms without saying which anomaly each removes. Students frequently misidentify the key, which makes the second normal form step meaningless. Some confuse partial and transitive dependencies. Others decompose too far, splitting tables where no anomaly exists and complicating queries. Many never check that the new tables can be joined back to reproduce the original data. Finally, normalizing a real department spreadsheet can expose colleagues' or customers' information; working from the supplied case shows the same reasoning without that risk. Showing the reassembled roster beside the original, row count for row count, is the simplest proof that the decomposition kept every fact.
Get a BU 453 Unit 3 example written to your instructions
Send the Unit 3 instructions and the rubric posted in your BU 453 classroom, together with whatever starting table the assignment supplies. The custom example prints sample rows, lists the dependencies it reads out of them, splits one at a time with keys marked, and names the anomaly each move removes. First custom sample free, back in 24 to 48 hours.
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BU 453 Unit 3 questions, answered
How far do I have to take the decomposition?
As far as the instructions name, and no further without saying so. Many undergraduate sections stop at third normal form because that is where the common update problems disappear. If you continue past it, treat the extra step as an argument rather than a habit: state the dependency that survives, show the split, and say what the additional tables cost when the data is read back.
Is it a mistake to leave a table denormalized?
Only when it happens by accident. Deliberate repetition is a normal design decision and gets credit here provided the exercise names what it bought, what problem it reintroduced, and which process is now responsible for keeping the duplicated values in step. What loses the criterion is a table that stops short of the required form with nothing written beside it, since a marker cannot tell judgment from an unfinished step.
Can I normalize a spreadsheet my department actually uses?
No, and a spreadsheet is deceptively easy to hand over because it looks harmless. The columns encode how the business tracks its own work, the rows are usually real customers, vendors or staff, and a graded file leaves the company for good. Work the table the assignment supplies. Your familiarity with how such a sheet grows sideways will show in the dependencies you notice, which is the part being marked.
Where can I find a free BU 453 Unit 3 sample paper?
The whole BU 453 Unit 3 normalization exercise is free on this page, with each step, the anomalies removed and margin notes. If your starting table differs, share the assignment and a custom decomposition follows at no cost, typically within two days.
How far should BU 453 Unit 3 decomposition go?
Usually to third normal form, checking Boyce-Codd where it matters. The sample stops there and explains two places where going further would add tables without removing any anomaly.