PLTW CSP Unit 1.1

Algorithm

A finite set of instructions that accomplish a specific task. An algorithm can be expressed in many kinds of notation, such as natural language, pseudocode, and flowcharts. Algorithms are essential to the way computers process data because they contain specific instructions for what a computer or program does.

Algorithmic Thinking

The process of solving problems by identifying the tasks required to solve a problem and using algorithms to clearly describe each task.

Program

A collection of program statements that performs a specific task when run by a computer. A program is often referred to as software.

Execute

To run a program or a single instruction.

Method

A predefined set of instructions that can be used to accomplish a task. It is available on a specific object. For example, a turtle object has a list of methods that can be used to manipulate the object, such as forward(), backward(), and so on.

Parameters

The input variables of a procedure. A set of information included to help a process or function operate as intended.

Input

Data that is given to an algorithm during the execution of a program and can affect the results of the algorithm.

Code Statement

A part of a program code that expresses an action to be carried out.

Output

Data or actions produced by an algorithm. Including 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.

Runtime

The duration of time a program is executing, from start to finish.

Program Input

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.

Python Terminal

The window that displays textual output generated by Python's print statement. The terminal also allows the user to type commands that are immediately executed upon pressing the Enter key.

Variable

An abstraction inside the program that can hold a value. Each variable has associated data storage that represents one value at a time, but that value can be a list or other collection that in turn contains multiple values.

Expression

A combination of variables, operators, or procedure calls that are evaluated and return a single value. The evaluation of expressions follows a set order of operations defined by the programming language.

Data Type

The kind of data being represented, such as a sequence of characters, an integer, or a true or false value, usually limiting the values allowed for the data.

Substring

part of an existing string

Code Segment

A collection of program statements that is part of a program.

Relational Operators

Used to test the relationship between two variables, expressions, or values. A comparison using a relational operator evaluates to a Boolean value. For example, a == b evaluates to true if a and b are equal; otherwise, it evaluates to false. Operators include: ==, !=, >, <, >=, and >=.

Boolean Expression

An expression that evaluates to either true or false; used in the conditional of an if structure.

Conditional Expression

A comparison, usually in a while or if statement, that evaluates to a Boolean value of True or False

Decidable Problem

A decision problem for which an algorithm can be written to produce correct output for all inputs (e.g., "Is the number even?").

Undecidable Problem

A decision problem for which no algorithm can be constructed that is always capable of providing a correct yes-or-no answer.

Arithmetic Operators

Mathematical processes that are part of most programming languages. They include addition, subtraction, multiplication, division, and modulus operators.

Zip File

A file that is stored in a compressed format, often containing multiple files

Compressed File

A file that is stored in a format that makes the file size smaller to save space on the computer.

Bug

Part of a program that causes an error or undesired output.

Debugging

The process of figuring out why code doesn't behave as expected and eliminating bugs to make it work as desired.

Sequential Statements

Code that executes in the order they appear in the code segment.

Initialize

When a variable is given a value for the first time. Until a variable is initialized, it is undefined.

Interpreter

A computer program that converts a program written in a higher-level language into a lower-level language and executes it, beginning execution before converting the entire program.

Block Strings

In Python, strings that begin with ''' and can span multiple lines. They are often used to temporarily deactivate code.

Incrementing Counter

A variable that stores an integer with increasing (or decreasing) value. For example, a common incrementing counter is a variable that starts at 0 and has 1 added to, resulting in subsequent values 1, 2, 3, etc.

Iteration

A repeating portion of an algorithm. Iteration repeats a specified number of times or until a given condition is met. Also used to refer to a single execution of that repetitive procedure.

List

An ordered collection of items or values. For example, [value1, value2, value3, ...] describes a list where value1 is the first element, value 2 is the second element, value 3 is the third element, and so on.

Array

An ordered collection of elements of the same type.

Literal

A literal is a fixed value in source code, such as 5 or "hello."

List Element

An individual value in a list that is assigned a unique index.

Loop Variable

In each iteration step, a variable set to a value in a sequence or other data collection.

Conditional Statement

A feature of a programming language that performs different computations or actions depending on whether a Boolean condition evaluates to true or false.

Selection

When parts of an algorithm are executed based on a condition being true or false.

Pseudocode

An outline of the basic ideas behind how algorithms will work.

Development Process

An iterative method that requires refinement and revision based on feedback, testing, or reflection throughout the process. This may require revisiting earlier phases of the process.

Requirements

Describes how a program should function and may include a description of user interactions that a program must provide.

Milestone

A task or other significant event in the development process. Milestones allow you to see the project achievements and to follow the development schedule.

Problem Decomposition

The process of breaking a complex problem or system into parts that are easier to conceive, understand, program, and maintain.

Incremental Development

A process that breaks the problem into smaller pieces and makes sure each piece works before adding it to the whole.

Design

Outline how to accomplish a given program specification.

Prototype

The first model of something.

Program Documentation

A written description of the function of a code segment, event, procedure, or program and how it was developed.