Ch. 1:

Defining Information Technology

– Learning the language of IT • Acronyms: GUI, WYSIWYG, etc.

• Jargon –“bit bucket”, “Right-click”, “hashtag” – http://www.unc.edu/~macmw/jargon.html

• Metaphors and Virtual Worlds –Everyday terms like “window”, “desktop” , “menu”, “ribbon” have special meanings.

–A metaphor is a familiar concept/item that helps us to understand a new concept/item.

Example Acronym: WYSIWYG

• "What you see is what you get " • Text is stored in computer memory as long line of letters, numbers, punctuation, control characters, etc.

• Original text editing software could not display formatting; users had to guess what it would look like when printed (Similar to HTML).

• WYSIWYG process displays data as a formatted page – “Print Preview”

Why Know The Right Word?

• There are many new terms in IT – Terms are invented for ideas, concepts and devices that never existed before – Some words are redefined or have multiple meanings • Use the right word at the right time whenever possible. • Concepts – explain in own words, use terms as you become familiar with them

Why Know The Right Word? (cont'd)

• Terminology is basic to learning a new subject – Words represent ideas and concepts –

Precision

in word use represents precision in understanding ideas • Communicating with others – To ask good questions and receive help – email, by telephone, helpdesk, built-in and online help facility (spelling!), in class, etc.

Computers Are Everywhere

• WWII – Computers were people!

• Many types: component/desktop, laptops, tablets, smart phones, music players, wireless mic’s, cars (anti-lock brakes, etc.) TV remotes, credit card readers. Others?

• General Purpose vs. Specific and/or Locked – Computers run software – Commercial (COTS), Custom, In-House, Hobby • Open Source vs. Proprietary

Hardware, Software, ‘Experience’

•

Hardware:

historically a term for metal items used in construction – Now also refers to physical parts of a computer (and other technology) – Functions implemented directly with wires and transistors. Hard to change.

•

Software

is a term created for computers – Means

programs

or

instructions

the computer follows to do “almost anything”.

– Applications vs. Folders & Files (Data/Info)

Software

• Software Stack (on “top” of hardware) – Concept used to structure and organize the software in contemporary computer systems – “Layers” that support user applications.

– Each layer implements functionality used by layers above. – Software instructs an agent to perform some function or action by giving a step-by-step process. – The agent is anything that can follow the instructions or “software program”.

– For software professionals, the agent is a computer. (Recall – people as computers.) 7

Software Stack 8

Hardware: Where's the Start Button?

• Many computers are left on most of the time –

Smart Phones? (Turn Off in class!)

–

Screen savers

prevent(ed) “burn-in” – Computer is reactivated by moving or clicking mouse, or pressing a key. (Feedback?) – Sometimes computers may be off (labs) – May need to boot (turn on). Careful!

Boot

•

Booting:

Start computer •

Rebooting:

Re-start computer • Boot instructions (special program or initialization software) are stored in a microchip called the boot ROM – ROM is Read-Only Memory • From “Pulling yourself up by your own bootstraps AKA ‘BOOTstrapping’"

Cables

-

connect components to computer and to power. They need to be plugged in correctly! Sockets and plugs are labeled with icons. May be color coded Newer: Wireless (BlueTooth, WirelessUSB, etc.)

Hardware: The Monitor

• Interactive video screen (CRT, LCD, etc.) • Displays information stored in computer memory or special video memory • Grid of small units called

pixels

–

(pic

ture

el

ement

s

) • Computer draws each pixel in the designated color for the image or figure • The more pixels in each row and column, the smoother and crisper the image •

“High resolution

”

• RGB

– Primary colors of light – Red – Green – Blue – Other colors created on screen by combining different amounts of primary colors

Colors

Motherboard

• Printed circuit board inside System Unit. • • • Contains most of the circuitry:

microprocessor chip (or Central Processing Unit – CPU)

and the

memory May be shielded against interference

Hardware: Microprocessor

• "Smart" part of system • Performs actual computing • "Micro" was adopted around 1980 to distinguish single chip circuitry from larger mainframes of the day.

• Term is somewhat archaic. Perhaps more correct to say “

processor

” or

CPU

.

• Latest Systems have Multi-Cores

Hardware: Memory

• Where program(s) and data are located while programs run • RAM: Random Access Memory • PC’s contain millions or billions of bytes of RAM: Megabytes (MB) / Gigabytes (GB) • What Random Access means: – Any item can be retrieved directly – Unlike sequential access – (example: Tape vs. CD or DVD)

Hardware: Hard Disk (HD/HDD)

• High-Capacity, persistent peripheral storage device – Stores programs and data not in immediate use by computer – Made from magnetized iron compound – Information remains if PC is on or off – Called

permanent

or

persistent

storage – Also called

secondary storage

–

Newer: Solid-State Drive (SSD)

Saving from RAM to Hard Disk

•

Saving

moves information from RAM to hard disk • Successful users save frequently !!!

– Make multiple copies/backups • Most RAM memory is

volatile

– Information is lost when power turns off – If computer fails or power-cycles,

only data on the hard disk may survive

• HD can also fail –

Have Backups !!!

Experience

• People: – meet online and marry – make unfortunate posts and lose their jobs – spend hours on music, videos, games, etc.

• Most interactions w/computers are recorded, virtual, or artificial • Recorded technology - Oldest form of IT – Recording a scene, performance, event, etc.

– Digital copies are approximations of reality – With today’s technology, in most cases the approximation is extremely accurate

Digital Information

• Transformation – Easy to enhance or embellish digital information – Photo editing, video editing, audio remixing, etc.

– Don’t believe your lying eyes!

–

Photoshop

has become a verb • Synthetic Complexity – Creation of new digital media: info. is

synthesized

– An alternate version of the world • Examples: animations, cartoons, video games

Digital Information

• Synthetic Complexity: Advantages? – Early animation: Each frame drawn by a person and the music recorded “live” – Contemporary animation: Also created one frame at a time, but by a computer – A “start scene,” an “ending scene,” and directions on how to modify the

start

to get to the

end

are processed by the computer to create the movie. Edited/Touch-Up.

– Digital sounds are added and synchronized to the images

Virtual Worlds

• Virtual reality: a world created by computers to

simulate

the physical world • It is not “real”, but is perceived “as if” it were • The full VR experience is still under development…but we see it all the time: – Keypads on a smart phone display – Spreadsheet software that look like accounting paper – GPS displays that show a map – Familiar mixed with new/inventive

Artificial Worlds

• Systems like iTunes, Facebook, Twitter, and Angry Birds are entirely new products of human imagination

. Or are they?

• Did/Do creators have unlimited flexibility?

• This flexibility to create (almost)

anything

is one of the exciting aspects of computing • Extended Abilities. Software can often do difficult tasks in a more user-friendly way.

• Not the standard techniques used previously • New “experts”. Example: video editing

Artificial Worlds

• New Phenomena: Twitter, Facebook, YouTube – Experiences that did not exist before they were created, at least in scale and pervasiveness.

– Some aspects, such as communication via phone and snail/email, did exist, but much more limited.

• New (?) Problems – New privacy concerns (also Opt-in vs. Opt-out) – Negative issues of scale – Spam ( junk mail ) – Scams (Nigerian Widow fraud) – online bullying and stalking

Data and Information

• Some say ‘Data’ and ‘Information’ are interchangeable words in computing • Better: Information is processed Data (“value added”). Relative comparison.

• Represented as bits (0’s and 1’s) • Digital information is stored on Web and Internet servers as

files

and

databases

• Databases are everywhere – Digital music (for example, iTunes) – Photo databases – Email and smart phone contacts, etc.

WWW: Sourced vs. Social Content

•

Sourced content:

produced for commercial purposes or to disseminate information.

• “Newspapers”, Government, Business, etc.

• Entirely(?) controlled by 1 organization/person •

Social content:

created by visitors to the site • Social networking, media sharing, gaming, and reference • Users generate much of the content • Mix? Search engines (Google)? Other?

Words for Ideas: Algorithm

• Algorithm: A

Precise

and

systematic

for solving a problem or producing a method specified result.

– (Discussed in more detail in later chapters!) – We use and invent algorithms all the time : • Arithmetic operations • Sending a greeting card • Searching for a number in a phonebook • Creating and Following a Recipe • Other

Algorithms and Programs

• Writing out the steps of an algorithm is part of

programming

–

A Program

is one or more algorithms, specialized to a specific set of conditions & assumptions, written in a specific programming language.

• “Clueless Computers” need to be told precisely what to do:

everything

must be spelled out • People

do

have a clue, so many things can be left out of an explanation when

people

have to follow directions or an algorithm.

Words for Ideas: “Abstract”

•

Abstract:

To Extract (“Remove” ) the basic concept, idea, or process from a situation. (Hide irrelevant details) • Abstraction is a more succinct and generalized form of the original concept.

– For example: parables and fables • the moral is abstracted from the story – Decide which details are relevant – Understand and apply the abstraction to other cases or situations

"Generalize"

• Process to recognize common idea(s) in two or more situations • Summarize expression of an idea, concept, or process that applies to many situations – e.g., faucet handles usually turn left for on and right for off – Caps usually twist left to loosen, right to tighten • Remember that generalizations will not apply in every single situation - Do not be too general!

"Operationally Attuned"

• Being aware of how a device or app works • Apply what we know about how device or system works to simplify use – e.g., cap lids usually twist left to loosen, so we are confident about which way to twist if stuck – We know this intuitively, but knowing it

explicitly

makes us operationally attuned

• THINKing

about how Information Technology (IT) works can make it simpler to use that technology. THINK (IBM slogan)

"Mnemonic"

• Memory aid – Often pronounceable words and phrases: – Spring ahead; Fall back – PILPOF - Plug in last, pull out first • May Help simplify use of technology – Easy memorization of infrequently used details – Can be overused, like Acronyms (LOL)

Analytical Thinking

• Using specific

facts and comparisons

to back up statements.

• Non-analytical statement: – World record in the mile run has improved • How much? Compared to what?

• How does this compare to other accomplishments?

• Analytical statements: – In 45 years, the world record in the mile improved from 3.59.4 to 3.43.13, a 7% improvement – The average 20 year old can run a mile in 7.5 minutes. The world record holder is twice as fast.

Benefits of Analytical Thinking

• Learning specific facts, and comparing them to other specific facts • Putting things in perspective – 7% historical improvement in mile run record compared to 100% difference between world record holder and average person • Increased clarity and focus on facts • Evidence for statements and ideas

Super Computers

• Analytical comparison of computer speeds – UNIVAC I • First commercial computer released in 1951 • Rate of 100,000 addition operations (adds) per second – 2010's Computers • Inexpensive laptop/palmtop systems • Rates: billions of adds per second • Factors of 10 – 100 thousand improvement over UNIVAC – IBM Sequoia • As of 2012 IBM Sequoia is the fastest in the world • Rate of

16.3 Quadrillion

floating points (decimal) adds per second • Factor of

163 billion

improvement over UNIVAC