Praxis Computer Sciences 5652

digital divide

the gulf between those who have ready access to computers and the Internet, and those who do not.

Solutions to digital divide

*Increase affordability

Empowering usersImprove the relevance of online content Internet infrastructure *developmentAddress gender gap in internet access

Creative Commons

A kind of copyright that makes it easier for people to copy, share, and build on your creative work, as long as they give you credit for it.

Open Source

Software that is created for free use by everyone

Copyright

the exclusive legal right, given to an originator or an assignee to print, publish, perform, film, or record literary, artistic, or musical material, and to authorize others to do the same.

Abstraction

Reducing information and detail to focus on essential characteristics.

Control abstraction

Don't care "How" it gets done

Data Abstraction

Representing or storing information with methods that separate layers of concerns so that the programmer can work with information while ignoring lower-level details about how the information is represented.

Abstraction allows....

you to modify "parts" of a program without messing up the larger program

Abstraction Hierarchy

Most general concepts on top of the hierarchy and specific concepts on the bottom

pattern recognition

looking for similarities among and within problems

Problem Decomposition

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

Binary

The binary number system is base 2, using only bits 0 and 1.

Hexadecimal

A base-16 number system that uses sixteen distinct symbols 0-9 and A-F to represent numbers from 0 to 15.

natural language

Person to Person

Oval (Flowchart)

start/end

Rectangle (flowchart)

Action or process

Dimond (Flowchart)

A choice

Arrow (flowchart)

Direction of a choice

Rhombus (flowchart)

Input / Output

Pseudocode

Shorthand notation for programming

Algorithm Analysis

A general process that determines the amount of resources (such as time and storage) necessary to execute any particular algorithm, most commonly using Big O notation, such as O(N) or O(N^2)

Linear Search

Each item in the list is checked in order.

Binary Search

An ordered list is divided in 2 with each comparison.

Bubble Sort

Moving through a list repeatedly, swapping elements that are in the wrong order.

Merge Sort

A list is split into individual lists, these are then combined (2 lists at a time).

recursive algorithm

solves a problem by breaking that problem into smaller subproblems, solving these subproblems, and combining the solutions.

Randomization

a process of randomly assigning subjects to different treatment groups

Heuristic solution

*A problem-solving technique which sacrifices accuracy to increase speed

*Rules of Thumb

Linear Algorithm

Sequential search, searches by checking each element in a set.

Quadratic

degree of 2

exponential function

Constant ratio increase

logarithmic function

What exponent is needed to get a number

control structure

*An instruction that determines the order in which other instructions in a program are executed

*If and Loops

Standard Operators

==, ||, &&

correctness (of a program)

depends on correctness of program components, including code segments and procedures

Extensibility

allows for future growth in a program

modifiability

software is able to be modified

Reusability software

The use of existing assets such as software, knowledge, code into new software

syntax error

a character or string incorrectly placed in a command or instruction that causes a failure in execution.

runtime error

becomes apparent when the program is executed

compile-time error

An error in the source code that makes it impossible to compile. Also called a "syntax error".

overflow error

A calculation produces a result that is greater than the computer can deal with or store with the available number of bits

round-off error

the error produced when a decimal result is rounded in order to provide a meaningful answer.

logic error

An error in a program that makes it do something other than what the programmer intended.

sequence

the order in which things happen or should happen

selection

A generic term for a type of programming statement (usually an if-statement) that uses a Boolean condition to determine, or select, whether or not to run a certain block of statements.

Iteration Control Structure

*Represents the computer's ability to repeat a series of instructions

*Loops

Assignment Operator

the "=" sign in an assignment statement

Arithmetic Operators

perform mathematical calculations

Relational Operators

Used to compare two values. Operators include =,<,>,<=,>=,<>

logical operators

&& [and]

|| [or]

! [not]

floating point

A type that represents numbers with fractional parts.

Global scope variables

*when variables are declared outside of a function

* variables declared globally can even be called

from other files

*can have unintended side effects

Local scope variable

only used for the block of code they are declared in.

Event-driven programming

the program is activated by events such as button clicks.

Dictionary and maps

stores data in an array

Stack

First In Last Out data storage

Push

Add item to top of stack

Pop

To remove an item from the top of a stack.

queue

Data stored in a "line"

"First in, First Out"

Enqueue

To add an item to the rear of a queue.

Dequeue

To remove an item from the front of a queue.

Characteristics of well-documented computer programs

*Usable

*Readable

*Modular

code review

a peer review process in which programmers check over one another's work to ensure its quality

end user

A representative consumer for whom a hardware or software product is designed.

apis

Application Programming Interface, how you define libraries and call them

Data Validation

the process of verifying that a program's input data is within the expected range

Data verification

validates that data is correct and accurate

Components of IDEs

*Text Editor

*Debugger

*Compliler

*Code Completion

*Language Support

*Plug-ins

Low level programming language

A programming language that provides little or no abstraction from a computer's instruction set architecture—commands or functions in the language map closely to processor instructions. Generally this refers to either machine code or assembly language.

High level programming language

A programming language that hides the details of how the computer hardware solves a problem and is therefore easier for a programmer to use.

Procedural Programming

method of programming that uses step-by-step instructions

object-oriented programming

designing a program by discovering objects, their properties, and their relationships

Programming Paradigm

A way of approaching problems; object-oriented, functional, and imperative paradigms are three major paradigms.

Functional Programming

A programming paradigm that uses functions to create programs.

Imperative Programming

where a developer writes code that describes in exacting detail the steps that the computer must take to accomplish the goal

class diagram

Rectangle with name at top, variables in the middle , and methods in the bottom

Inheritance

when subclass get the variables and methods of a super class

overloading a method

giving two methods the same name but different method signatures

overriding a method

redefining a method in a subclass

compilation

turning programming language into machine language

interpretation

the result of a program

source code

A program in a high-level language before being compiled.

object code

The output of the compiler after it translates the program.

8 ______ make up 1 _______

bits, byte

How to remember the smallest bits to largest bits

Kilo

Mega

Giga

Tera

Lossy data compression

data compression technique where the number of bits needed to store or transmit information is reduced, but the original data cannot be reconstructed

Lossless data compression

reduces the file size without any loss of data quality

Encoding

the processing of information so that it can be stored.

Encryption

a process of encoding messages to keep them secret, so only "authorized" parties can read it.

*Need a Key

simulation models

computerized models that can be tested under different scenarios to identify acceptable solutions to problems

modeling

building a model

trace code

Writing down the values of the variables and how they change each time the body of the loop executes.

redundancy

Ability to provide continued service, no matter what happens

Backups

copies of files that you can use to replace the originals if they're lost or damaged

Data Collection

The process of acquiring existing information or developing new information.

aggregation

information is gathered and expressed in a summary form, for purposes such as statistical analysis.

data generation

Development of data, frequently qualitative rather than numerical, by the data collector.

Data generated by sensors

input by physical environment