Two readers, one design
The shop owner reads your design to decide if she wants it. A builder you have never met reads it to make it.
The owner wants to know what she gets and what it costs. The builder wants every name, type and rule. One set of notes has to serve both.
Key words
| Word | What it means |
|---|---|
| Client | the person or business who asked for the work |
| Third party | somebody else, outside the project, who may use your notes |
| Audience | the people who will read or use what you write |
| Technical vocabulary | the exact words of the subject, such as primary key |
| Attribute | one fact about an entity, such as a name |
| Data dictionary | a table that describes every attribute: its type, size and rules |
| Primary key | an attribute whose value is different for every row |
| Personal data | facts about a living person who can be named |
| Diagram | a picture that shows structure, such as an ERD |
| Option | one of several ways to do something, with good and bad points |
The cells students fill in are left blank in this preview.
By the end of this lesson
Note
I can write design notes that let a client decide and let a third party build, using words and diagrams together.
Starter
Have a go
Starter
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
This is practice
Important
The real task comes from the exam board. This lesson uses an invented organisation and its own made-up data. Your teacher tells you how the real tasks are set and what you may bring.
Worked example: what each reader needs
| Reader | Needs | Style |
|---|---|---|
| Client | What it does, what it costs, the choices and the risks | Plain words, a simple picture |
| Third party builder | Every table, key, type, size, rule and step | Exact words, full diagram and dictionary |
The cells students fill in are left blank in this preview.
Write in layers
Start each part with a short plain summary for the client. Follow it with the exact detail for the builder.
Put the diagram first, then the words that explain it. Use the exact technical words, but explain each one the first time.
Worked example: weak and strong notes
| Weak | Strong |
|---|---|
| The data is stored in tables. | Four tables hold the data: CUSTOMER, SALE, ITEM and SALE_LINE. The ERD shows how they join. |
| Points are worked out. | Step 5 gives one point for each whole pound in a sale. The input is the loaded sale rows. The output is a points total for each customer. |
| Bad data is dealt with. | A row with a missing name or an amount outside 1 to 1000 pounds goes to the problem list, and is not loaded. |
The cells students fill in are left blank in this preview.