HCI and Libaries

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HCI- Human computer interface.

allows user to interact with the computer

3 types:

1) Command Driven

2) Menu Driven

3) Graphics GUI

Describes the way in which humans give input and recieve outputs

Command Driven

Has to types in special command words

eg DOS, UNIX and Linux are command interfaces

Advantages quick to use

Disadvantages hard to remember commands

Menu Driven

Offers user a list of options which they can select by pressing particular keys

Advantage: easy to use

Disadvantage: Getting on particular option can involve going through different menu screens

Graphical user interfaces

WIMP systems (windows icons menus pointers

Options are represented by small pictures (icons) arranged in rectanguar boxes

Advantage: Very easy to use, especially for beginners. Shortens learning time for beginners

Disadvantage: Needs a large amount of memory, so needs lots of RAM to run properly, also takes up large amount of hard drive space

User interface design

Should be:

User friendly

consistent in operation, screen layout (BBC always has banner at top)

colours should be chosen carefully (Good contrast)

Sound can be used for notifications(Should have an off button)

online help is useful

Voice/ Speech interface

Advantages

Speech is natural for interaction, not necessary to sit at a keyboard.

No Training needed

Disadvantages

Even the best make errors, noises in a room will cause errors (TV, water ect.)

Works best when microphone is close(Microphone on desk less useful)

Touch Driven

Advantages

Big screen is ideal for web browsing, pictures and movies

touchscreen apps usually have simpler interfaces, more intuitive

Disadvantages:

Screen may be too small to use with no stylus

Big screen leads to low battery life

Touch cant be read easily in sunlight

Screens get dirty easily

IDE- integrated development environment

Libraries- gives functions that are additional to main language

Functions can be imported and used at the start of the code.

Libraries will give predesigned program scripts that are required by many users

They save users from redeveloping the same pieces of code repeatedly.

Provide robust, well tested code, and shorten development time.