CMPE003

Personal Computer Concepts: Software and Hardware

Spring 1996

Lectures 7 and 8

CHAPTER7

THE USER INTERFACE

* Supports Interaction Between User and
Program

     * Many "flavors"

     * Depends on "model" of user,      task,          and computer environment  
     
     * Easy to learn vs. Easy to use




                         USER INTERFACE
                               ^
                               |
                               v
                      APPLICATION SOFTWARE
                                ^
                               |
                               v
                   OPERATING SYSTEM SOFTWARE
                                ^
                               |
                               v
                            HARDWARE

* USER INTERFACE "FLAVORS"

* Command Line

* Function Keys

* Menu



* USER INTERFACE "FLAVORS"

* Graphical (GUI)

     * "point and click"

     * "drag and drop"

     *  requires mouse or other 
          pointing device

     *  requires full screen
          interaction

* Future

     * voice 

     * eye tracking

     * brain waves ...




"LAWS OF THE USER INTERFACE"

* Learning and Recall of Commands 

     * easy to learn & remember

* Predictability

     * similar tasks should work  similarly

* Efficiency of Use

     * easy for novice & easier for "pro"    
     ("shortcuts" for experts)

* Error Prevention

     * software should reduce possibility of user
errors



* Flexibility

     * software should allow users to "un-do" 

Class Notes - Lecture : Draft 1

User Interface

 The user interface defines the way in which the user will interact with 
the the computer. The order of hierarchy that a user interacts with is the 
user interface, applications, operating system, and hardware. There are 
several different user interfaces available. 
 In a DOS environment a command line user interface is utilized. For 
example at the command, format a:, typed at the DOS prompt would format the 
floppy disk in drive a: (C:\> format a:). Other user interfaces that were 
created utilize pull-down menus, function keys, and a mouse. A GUI or 
graphical user interface uses a "point and click" mechanism to interact 
with computer applications. A GUI requires a pointing device, like a 
mouse, and a full screen. 

 A good user interface must have commands that are easy to learn and easy 
to memorize, offer shortcuts for the expert, help prevent user errors, 
allow the user to change his/her mind, and have some consistency that 
allows for predictability in the programs. 

 User interfaces will continually evolve and the ways in which a user 
interacts with a computer will change. The future may utilize speech 
recogntion (to a certain level speech recogntion is available now), eye 
tracking, and the use of electrical potentials to track brain waves.   
 
Spreadsheets

Quattro pro is the spreadsheet program utilized for the lab assignments.
In each cell of a page, the user can type in numbers, text, formulas, or 
a function. Functions are also available on the tool bar. For example to 
sum a set of numbers, the user can either type @SUM(B3..B8) or use the 
sum symbol in the tool bar after highlighting the area to be added. 
Functions exist for several different disciplines, there are statistic 
functions, economic functions, and many more. The best way to search for 
a function that may be of use is to go to the help menu and use search to 
find information about a topic. Quattro pro also allows the user to make 
graphs of the data held in the table. Check the help menu or coach icon 
to read about graphics or to go through a tutorial. 

Geographic databases

In class two videos were shown displaying information about geographical 
information databases. They provided a way to visualize and query 
geographical databases.