DRAFT — under teacher review.
Essential Terms — C02
Hamilton College · Year 12 · 2026
A glossary of every term you need to recognise and use correctly across C02. Click a term to expand its definition. Use this as a vocabulary self-check before your C2-1 (Poster Peer-Assessment) and C2-2 (Hand-Drawn Diagrams) validations — if you can't define a term in your own words, you can't defend it under questioning.
Topics covered
- Data collection methods (interviews, surveys, observations, reports)
- User stories
- Context diagrams
- Data flow diagrams
- Use case diagrams
Glossary
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- Actor An entity that can interact with the software solution as shown in a use case diagram
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- Association A relationship between two elements in a use case diagram
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- Close-ended questions Questions that can be answered with a finite set of responses
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- Context diagram A visualisation of a system in its entirety that indicates the data that is passed into and out of the system
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- Data Raw, unprocessed facts and figures
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- Data flow The movement of a piece or collection of data within an information system, as shown in context diagrams and data flow diagrams (DFDs)
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- Data flow diagram (DFD) A graphical visualisation of the flow of information within a system, including data provided by external entities
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- Data store A representation of a collection of data that is stored in some way within a system
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- Entity The users or external systems that interact with the system being created
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- Extend A relationship between use cases where one use case has optional or additional functionality, which is represented in a use case diagram as a second use case
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- Generalisation A parent-child relationship between two elements in a use case diagram
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- Include A relationship between use cases where one use case is tied to, or relies upon, the functionality contained within another use case
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- Interview A face-to-face meeting between people for consultative purposes
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- Observation A method of data collection that involves physically observing how a system operates and how it is used
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- Open-ended questions Questions where the number of potential answers is infinite
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- Process (context diagram) An abstract representation of the whole system being created
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- Process (data flow diagram) An abstract representation of a function within a system
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- Qualitative data Data that consists of descriptive details, usually gathered via surveys or interviews
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- Quantitative data Data that can be easily processed in a statistical manner, usually composed of definite numbers
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- Relationship The connections between elements within a use case diagram
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- Report A written document providing a summary or finding in relation to the context or system being analysed
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- Survey A set of questions that ask for a response to be selected from a list of alternatives
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- System boundary A rectangle around relevant use cases that indicates the use cases that are within the scope of the solution
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- Unified Modeling Language (UML) A general-purpose visual modelling language
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- Use case A representation of the transactions or functions a user (actor) can complete in a system, as shown in a use case diagram
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- Use case diagram (UCD) A method of describing how a user interacts with a system, using Unified Modeling Language (UML)
See also
- Context Diagram — the highest-level view of your system
- Context Diagram vs Data Flow Diagram — what changes between Level 0 and Level 1
- What Is an Entity — entities aren't only people
- Excalidraw Diagram Starters — pre-framed canvases for rehearsing all three diagrams