Understanding Data Flow Diagrams

What is the primary purpose of a Data Flow Diagram (DFD)?

• To represent the physical layout of a system

• To illustrate the flow of data within a system

• To show the organisational hierarchy

• To display the network architecture

Which of the following is considered an external entity in a DFD?

• A database

• A user

• A process

• A data flow

In a DFD, what does a large rectangle symbol typically represent?

• A process

• A data store

• An external entity

• A data flow

What is the rule regarding data flows in a Level 1 DFD?

• Data flows can be bidirectional

• Data flows must be labelled

• Data flows do not need to connect to a process

• Data flows can be left unlabelled

Which of the following is NOT a standard symbol used in DFDs?

• Circle

• Arrow

• Triangle

• Rectangle

What must every data flow connect to in a DFD?

• A data store

• An external entity

• A process

• A network

In a DFD, what does an ellipse (Circle) symbol typically represent?

• A data store

• A process

• An external entity

• A data flow

What is the minimum number of inputs or outputs required for each external entity in a Level 1 DFD?

• None

• One

• Two

• Three

Which of the following is a rule for drawing Level 1 DFDs?

• Data flows can be circular

• Every process must have at least one input and/or one output data flow

• External entities can be connected directly to data stores

• Data flows can be left unlabelled

What does a thin rectangle symbol represent in a DFD?

• A process

• A data store

• An external entity

• A data flow