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 aformatted 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 – (picture elements )

• 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”

Colors• RGB– Primary colors

of light– Red– Green– Blue– Other colors

created on screen by combining different amounts of primary 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 method

for solving a problem or producing a 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