One could argue for many different criteria to be included in the 'top four'. This assignment will argue for the four criteria listed below and suggest metrics that might be applied.

Criteria
1 Access times
2 Chunking
3 Interface usability
4 Accessibility

Justification for 'Access times':
In institutional settings these days access times are less of an issue due to the wider adoption of broadband. However in domestic situations users have a wide variety of connection speeds, some even as low as 28.8 Kbps dialup. Many multimedia applications generate very large files that consume a large proportion of the available bandwidth. Poor design choices and inefficient coding can also contribute, as can the file formats chosen. (.wav compared to .mp3, for example).

To illustrate the point, a movie of 30 seconds duration was created in Camtasia Studio and saved in a number of different formats. (Settings were kept standard, within the options available to each format). The results are tabulated below:

Whatever the reason, long download times are unacceptable. Learners, though often a captive audience, will lose interest or become frustrated if the access time exceeds 30 seconds or so.

Even when Multimedia files are optimised for quick downloads there may be lengthy delays. It is important to cater for this by allowing the download to carry on in the background while the user maintains engagement in another part of the site. This can be done by having downloads open in a new window that can be minimised. Alternative methods of obtaining/accessing the file should also be provided, such as a downloadable .zip file.

Metrics for 'Access times'

• Access times for any item of multimedia can be logged and tabulated using a range of browsers and connection speeds from 28.8 kbps up to broadband.
• Does this multimedia element download in a new window?
• Can this multimedia element be downloaded as a .zip file?

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Justification for 'Chunking'
Content presented online must be divided into digestible morsels if it is to stand a chance of being retained. This is well known in terms of writing delivered on web-pages, but also applies to input material of any great length depth or complexity presented through multimedia. Quite apart from issues of file-size and access times, human attention span and short-term memory severely limit the amount of information that can be assimilated in one go. A video of a one-hour lecture would be a foolish proposition in terms of both human and machine 'bandwidth'. Video must be chunked relative to the amount of information (not more than nine discrete items of information per chunk) and predicted attention span. Attention span is a function of the degree of engagement the material induces. A good movie retains our attention for two hours and more, but a lecture delivered in a tinny voice by a tiny lecturer on a 320x240 pixel screen would be an uphill battle.

Metrics for 'Chunking'

• Measure the playing time of the multimedia element
• Count of number of discrete items of information in the multimedia element
• User testing to observe user behaviour during interaction. (body language, verbal comments, facial expression)
• User testing to test understanding/retention, post interaction.

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Justification for 'Interface usability'

'Consistency is one of the most powerful usability principles: when things always behave the same, users don't have to worry about what will happen. Instead, they know what will happen based on earlier experience'.
--Jakob Nielsen's Alertbox: 'Top ten mistakes in web design'

Although referring to website design, this principle applies just as much to multimedia elements as it does to web pages. The interface and controls should be intuitive, requiring little or no conscious interpretation on the part of the user. They should allow users to identify and manipulate variables efficiently and undo any errors quickly.

Metrics for 'Interface usability'
This is a rather subjective criterion. As such, it may be best evaluated through user testing:
'…to evaluate interaction designs you must closely observe individual users as they perform tasks with the user interface. Listening to what people say is misleading: you have to watch what they actually do.'
--Jakob Nielsen's Alertbox, August 25, 2003 'Usability 101'

Nielsen goes on to define five parameters, or 'quality components' in usability evaluation, listed below. Metrics that might be applied to some of Nielsen's components are suggested:

• Learnability: How easy is it for users to accomplish basic tasks the first time they encounter the design?
  Metric: Set a task for the test group the first time they use the interface and time them to completion.
• Efficiency: Once users have learned the design, how quickly can they perform tasks?
  Metric: Repeat with a new task.
• Memorability: When users return to the design after a period of not using it, how easily can they reestablish proficiency?
  Metric: Timed task
• Errors: How many errors do users make, how severe are these errors, and how easily can they recover from the errors?
  Metric: Observe performance of task specified above and count the number of wrong turns the user takes and how many clicks / how long it takes to undo
• Satisfaction: How pleasant is it to use the design?
  Metric: Observe behaviour during the test; ask them for a subjective impression.

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Justification for 'Accessibility'
"The power of the Web is in its universality. Access by everyone regardless of disability is an essential aspect."
-- Tim Berners-Lee, W3C Director

With multimedia, visual and auditory disabilities are largely dealt with at the local level on the user's machine.
The main issue adressed here is compatibility. It is frustrating to encounter multimedia elements that will not function on a particular system. It is also important to inform users when an item will not open in the current browser / version and direct them to a download for an update or plug-in.

Metrics for 'Accessibility'

• Checkbox for each item of software facilitated
• Checkboxes for versions facilitated
• Checkboxes for international standards validation
• Directions to plugin/program download provided?
  

I used a free font called 'j.d.' downloaded from 'emerald city fontwerks' I think it is appropriate to use a script font like this to compliment the intimate message. The size of the .GIF file is 5.43 KB

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Activity 3.4 - Decorate your haiku

Using Fireworks MX I changed the background and font colours and added a layer with an 'oil on water' effect to suggest mother of pearl (or satin sheets?). I experimented with my digital camera and a string of (fake) pearls on a sheet of white A4 to get a suitable copyright-free image. I resized the jpeg and removed the background in Adobe PhotoDeluxe, then imported it into the Fireworks project and added it (twice) in a new layer. Finally, I added another layer in plain pink and increased its size to 20px larger than the rest, to act as a subtle frame. I used the export wizard to optimise the file size at 19.2 Kb.