AP Computer Science Principles- Big Idea 1

Program/Software

- is a collection of program statements that performs a specific task when run by a computer

- it needs to work for a variety of inputs and situations

- it is a set of instructions that a computer needs to follow in order to perform a task

Code Segment

- is a collection of program statements that is PART of a program.

The Behavior (of a program)

-is how a program functions during execution and is often described by how a user interacts with it.

-A program can be described broadly by WHAT IT DOES, AND/OR in more detail by both what the program does and HOW THE PROGRAM STATEMENTS ACCOMPLISH THIS FUNCTION

Program Inputs

-are DATA sent to a computer for processing by a program

-Input can come in a variety of forms, such as tactile, audio, visual, or text.

Event

-is associated with an action and supplies input data to a program

-can be generated when a key is pressed, a mouse is clicked, a program is started, or any other defined action occurs that affects the flow of execution

-Inputs usually affect the output produced by a program

-Input can come from a user or other programs

Program Outputs

-are any data sent from a program to a device

-Program output can come in a variety of forms, such as tactile, audio, visual, or text

Program Documentation

-is a Written Description of the function of a code segment, event, procedure, or program and how it was developed

-helps in developing and maintaining correct programs when working individually or in collaborative programming environments

Comments

-are a form of program documentation written into the program to be READ BY THE PEOPLE and do not affect how a program runs

Logic Error

-is a mistake in the algorithm or program that causes it to behave incorrectly or unexpectedly

Syntax Error

-is a mistake in the program where the rules of the programming language are not followed

Run-time Error

-is a mistake in the program that occurs during the EXECUTION of a program

Overflow Error

-is an error that occurs when a computer attempts to handle a number that is outside of the defined range of values

Testing

-uses defined inputs to ensure that an algorithm or program is producing the expected outcomes

Topic 1.1- Collaboration

-Collaboration is crucial when developing computing innovations, because having multiple perspectives offers opportunities to improve the design of innovations and help avoid bias

-Collaboration includes consultation and communication

-Common models like pair programming exist to facilitate collabs

-Collaboration: Communication, Consensus Building, Conflict resolution, Negotiation

Topic 1.2- Program Function and Purpose

-Developers create and innovate using an iterative design process that is user-focused

-The purpose of computing innovations is to solve problems or to pursue interests through creative expression

-Programs are event driven with triggers

-Action may be initiated by the user or another program/device

-Innovations include apps, physical devices and systems

-Description of code segments say what it does and include how it performs

-Code segments have to work in a variety of different scenarios and lists

Topic 1.3- Program Design and Development

-Programs explore the problem/purpose, developers determine requirements and limitations/user concerns

-A development process can be ordered and intentional, or exploratory in nature

-There are multiple development processes. The following phases are commonly used when developing a program: 1. investigating and reflecting 2. designing 3. prototyping 4. testing

-The design of a program incorporates investigation to determine its requirements.

-Some ways investigation can be performed are as follows: 1. collecting data through surveys 2. user testing 3. interviews 4. direct observations

Topic 1.4- Identifying and Correcting Errors

-The following are effective ways to find and correct errors: 1. test cases 2. hand tracing 3. visualizations 4. debuggers 5. adding extra output statement(s)

-Program requirements are needed to identify appropriate defined inputs for testing

-Hand Tracing: most useful with iterations or loops, it is simply writing out the values of the variables within the loops it iterates to determine if the outcome is correct

-Visualizations: determine if a program is working correctly by using graphs, charts, images

-Adding extra output statements: helps find and fix errors, allows computer to do more work

-Debuggers: use software that runs a program, allowing it to be paused

and tested while its running to see if it work properly