CS1001CS1001Lecture 10Lecture 10

OverviewOverview HTML and UsabilityHTML and Usability CopyrightCopyright

GoalsGoals Know some cognitive guidelines Know some cognitive guidelines

for designing effective for designing effective hypermedia documentshypermedia documents

Know some of the issues Know some of the issues surrounding digital copyrightsurrounding digital copyright

How is source code licensed? How is source code licensed? What do you own?What do you own?

AssignmentsAssignments

Brookshear: Ch 8.2, 8.3 (Read)Brookshear: Ch 8.2, 8.3 (Read) Hypermedia/UsabilityHypermedia/Usability

– http://www.ibiblio.org/pioneers/bush.htmlhttp://www.ibiblio.org/pioneers/bush.html– http://www.theatlantic.com/unbound/flashbks/computer/bushf.htmhttp://www.theatlantic.com/unbound/flashbks/computer/bushf.htm

CopyrightCopyright Read linked documents on these Read linked documents on these

slides (slides will be posted in slides (slides will be posted in courseworks)courseworks)

HypermediaHypermedia Hypermedia is designed to link Hypermedia is designed to link

information togetherinformation together Hypermedia facilitates easier Hypermedia facilitates easier

access to information (when access to information (when implemented correctly)implemented correctly)

Origins of HypermediaOrigins of Hypermedia Vannevar Bush, 1945 Vannevar Bush, 1945

(FDR’s science adviser)(FDR’s science adviser) Devised the “Memex” – a Devised the “Memex” – a

theoreticaltheoretical device for device for retrieving cross linked retrieving cross linked informationinformation– Based on microfilm and eye Based on microfilm and eye

tracking technology (which tracking technology (which did not exist yet)did not exist yet)

The MemexThe Memex Wholly new forms of encyclopedias will appear, ready-Wholly new forms of encyclopedias will appear, ready-

made with a mesh of associative trails running through made with a mesh of associative trails running through them, ready to be dropped into the memex and there them, ready to be dropped into the memex and there amplified. The lawyer has at his touch the associated amplified. The lawyer has at his touch the associated opinions and decisions of his whole experience, and of the opinions and decisions of his whole experience, and of the experience of friends and authorities… (Bush, 1945)experience of friends and authorities… (Bush, 1945)

What Information is What Information is Appropriate for Appropriate for Hypermedia?Hypermedia? Golden Rules of Hypertext Golden Rules of Hypertext

(Schneiderman, 1989); Choose (Schneiderman, 1989); Choose projects that adhere to the following:projects that adhere to the following:– There is a large body of information There is a large body of information

organized into numerous fragmentsorganized into numerous fragments– The fragments relate to one anotherThe fragments relate to one another– The user needs only a small fraction of the The user needs only a small fraction of the

fragments at any timefragments at any time– (Note: (Note: MostMost information satisfies these information satisfies these

requirements)requirements)

Object-Action Interface Object-Action Interface Model for Web Site Model for Web Site DesignDesign TaskTask

– Structured information objects (for Structured information objects (for example, hierarchies, networks)example, hierarchies, networks)

– Information actions (for example, Information actions (for example, searching, linking)searching, linking)

InterfaceInterface– Metaphors for information objectsMetaphors for information objects– Handles for actions (for example, querying, Handles for actions (for example, querying,

zooming)zooming)

Example Information Example Information Aggregation Aggregation StrategiesStrategies Short unstructured listsShort unstructured lists Linear structuresLinear structures Arrays or tablesArrays or tables Hierarchies, treesHierarchies, trees Multitrees, faceted retrievalMultitrees, faceted retrieval NetworksNetworks

Example MetaphorsExample Metaphors File cabinet with folders and File cabinet with folders and

documentsdocuments Book with chaptersBook with chapters Encyclopedia with articlesEncyclopedia with articles Television with channelsTelevision with channels Shopping mall with storesShopping mall with stores Museum with exhibitsMuseum with exhibits

CopyrightCopyright Is information free?Is information free?

– If we apply a “library” metaphor to the If we apply a “library” metaphor to the internet, then typically we are used to internet, then typically we are used to libraries being freelibraries being free

Fundamental problem: CopyingFundamental problem: Copying– You can’t easily copy books (there is some You can’t easily copy books (there is some

effort involved); Digital data can be copied effort involved); Digital data can be copied extremely easilyextremely easily

– Digital copies are Digital copies are losslesslossless (they are as (they are as pristine as the original)pristine as the original)

CopyrightCopyright When you publish on the internet, When you publish on the internet,

your content is implicitly your content is implicitly copyrighted along with images, copyrighted along with images, sounds, etcsounds, etc

However, as with books, people However, as with books, people are free to re-express your are free to re-express your content in their own wordscontent in their own words

Software and Software and CopyrightCopyright Fundamental Problem: Software Fundamental Problem: Software

isis information (it’s just code) information (it’s just code) Does this mean that you can re-Does this mean that you can re-

implement someone else’s implement someone else’s algorithm?algorithm?

LicensesLicenses Buy the software for unlimited Buy the software for unlimited

useuse Lease the software as a serviceLease the software as a service GPL (General Public License) and GPL (General Public License) and

other free licensesother free licenses