1. Fluency with Information Technology
7th Edition
Chapter 2
Exploring the Human Computer Interface

2. Learning Objectives 1.1 Name several computing features you know
1.2 Explain how metaphors are used in computing
1.3 Describe the desktop metaphor, giving examples of appropriate icons
1.4 Describe the touch metaphor, giving sample motions
1.5 Explain how desktop and touch metaphors differ

3. 1.1 Naming Computing Features
Feedback
Interface Consistency
“Blank” Instances
Perfect reproduction (Copy/Paste and Find and Replace All)
Placeholders

4. Computers and Feedback
When computers assist us, we need:
An indicator of our “assistant’s” overall task progress
Notification of when the task is complete, so another task could be assigned
These indicators and notifications are called feedback

5. Types of Feedback
One form of feedback is seen when the computer is performing a time-consuming operation
The cursor is sometimes replaced by a different icon:
Or by a progress bar:

6. Identifying Interface Consistency
No matter who makes the software, icons and menus tend to be similar
We see this when interfaces are created by a specific company (like Microsoft, Apple, or Linux Mint)
Interfaces with similar features often have similar menu names, like File and Edit
Expected functions like Cut, Copy, and Paste, can be found in many Edit menus

7. Consistent Interfaces Support Exploration
Consistency can provide a sense of familiarity with a new application
Familiarity makes exploration easier:
Clicking around to explore the application to see what features are available
Blazing away to try using the application in a way you haven’t done before, like creating a blank instance (such as a new document or calendar entry)

8. Creating a Blank Instance
A blank instance is an empty structure to hold (record) all of the properties of that file and store its content
Under File you usually find a command, New
New creates a blank instance of the kind of files the application creates
Example: A new/empty address book entry is ready to hold names, images, and phone numbers associated with the new contact

9. Figure 2.1 Creating a New Blank Instance
The user-facing part of a blank instance of contact information from an electronic address book; the new instance is a created structure inside the computer with empty fields, as shown.

10. Perfect Reproduction: Digital Information
Computers encode information as a sequence of binary digits, zeros and ones:
Because of the use of two digits, we call it digital information
Using only zeroes and ones means that digital information can be perfectly reproduced or replicated

11. Perfect Reproduction: An Exact Duplicate
A perfect reproduction, or copy, is made by duplicating the sequence of zeros and ones
This is one way digital improves on analog information
Analog information comes from or is stored on a continuously variable medium
An analog copy of an image, for example, might come out too dark or too light when compared to the original

12. Perfect Reproduction in Action: Copy/Paste
Copy and Paste operations are available in many applications
When editing a file, you can either create content from scratch or use Copy/Paste (C/P) to reproduce it from another location
C/P is generally faster and less error prone

13. Perfect Reproduction in Action: Find and Replace All
In Find/Replace editing operations, first the source content to Find is identified in the document, then the target content to Replace it with
Find/Replace All (F/RA) is an all-at-once version of Copy/Paste
Use an abbreviation of a long name or title as a placeholder technique, then use F/RA to put in the correct name all at once

14. Using F/RA with Placeholders
Use an abbreviation of a long name or title as a placeholder technique, then use F/RA to put in the correct name all at once
Example: replacing all instances in your paper of a placeholder like tur with Alan Turing
Question: why shouldn’t you use a placeholder like at for the operation above?

15. 1.2 Computing and Metaphors
In computing, a metaphor is an icon, image, or approach used as representative or symbolic of a computation
When designers create a technology, they may use metaphors to help users know how to operate their devices without having to read a manual for every function

16. 1.3 The Desktop Metaphor
In the 1970s, the first personal computer (the Alto) was developed by Xerox PARC
It introduced a graphical user interface, a change from the existing text-based user interface
Since the Alto was designed for office use, the metaphor that was used for the screen was the desktop
Other office metaphors: files, folders, documents

17. The Desktop Metaphor in Action
Steve Jobs and Steve Wozniak founded Apple, and started by building computers with text- based user interfaces first
Apple Macintosh was the first successful graphical user interface (GUI) personal computer, extending ideas from Alto with new icons
Microsoft introduced Windows a year and a half later

18. A Metaphor for the New GUI: The Mouse
The Mac first introduced the mouse to the public
Apple did not invent it
Stanford Research Institute invented the mouse in December 1968
When introduced, they called it a mouse and later didn’t know why they didn’t change the name

19. Figure 2.5 The Mouse
Evolution of the mouse: (a) A prototype of Englebart’s 1967 invention, (b) Alto’s three-button mouse, and (c) the original Macintosh one-button mouse.

20. 1.4 The Touch Metaphor
Users touch the content on the screens of their smartphones, tablets, and other mobile devices, with either their fingers or styluses
Example: the Cover Flow mechanism for scanning through a list, using a sweeping motion of the pointer:

21. Table 2.1 Touch Gestures Gestures Description Typical Use
Typical Result
Sweep or Swipe
Move finger across surface
Scan through a list
Items sweep by, with one selected
Tap
Light one-finger tap on surface
Select or choose
Item identified
Double Tap
Light two-finger tap on surface
Launch
Selected item opens/starts
Drag
Move selected item by pulling
Move item
Item in new position
Pinch Fingers/Pull Fingers Apart
Contract/expand separation between fingers
Shrink/zoom
Image/view is resized
Two-Finger Scroll
Navigate
Move around an image or item
Flick
Quick sweep; finger leaves surface
Express acceleration
Sustained sweep

22. 1.5 Metaphors: Touch vs. Desktop
Touch changes how humans interact with the computer
With the touch metaphor, you move the content to where you want it to be
With the desktop metaphor, you slide a window over the content
Direction of motion is opposite between touch and desktop metaphors

23. Summary
Because designers use consistent interfaces, helpful metaphors, and standardized functions, we can “click around” and “blaze away” without fear
Making exact copies is a fundamental property of digital information that we use in multiple ways
Copy Paste (C/P) and Find and Replace All (F/RA) are standard operations that simplify computer use
Metaphors are helpful because they support us in learning and using software
The desktop metaphor has existed for some time; the touch metaphor is newer: they will continue to co-exist for the foreseeable future