explicit acceptance criteria should be established when the requirements document is written
user friendly is vague, we rather use:
time for users to learn specific functions
speed of tasks performance
rate of errors by users
user retention of commands over time
subjective user satisfaction
An acceptance specification
The subjects will be 35 secretaries hired from an employment agency. They have no word-processing experience, but have typing skills in the range of 35 to 50 words per minute.
They will be given 45 minutes of training on the basic features. At least 30 of the 35 secretaries should be able to complete, within 30 minutes, 80 percent of the typing and editing tasks in the enclosed benchmark test correctly.
another specification
After 4 days of regular use of the system, 25 of these 35 secretaries should be able to carry out, within 20 minutes, the advanced editing tasks in the second benchmark test, and should make fewer than six errors. it focuses on performance after regular use
After two weeks, at least 15 of the test subjects should be recalled and should perform the third benchmark test. In 40 minutes, at least 10 of the subjects should be able to complete 75% of the tasks correctly.
Dopo due mesi, vengono richiamate 15 delle segretarie prima utilizzate. Gli viene assegnato il compito di scrivere un brano per completare la fase di sperimentazione. In 40 minuti, almeno 10 segretarie devono essere in grado di completare almeno il 75% del compito in modo corretto. iit focuses on retention
still on acceptance testing
in a large system 8 to 10 tests will be carried out on ° components of the interface, with different user communities
other criteria may be also considered:
subjective satisfaction
o/p comprensibility
system response time
installation procedures
printed documentation
graphics appeal
acceptance context
if precise acceptance criteria are established, both customer and interface developer benefit
user friendliness is avoided (as a standard to comply with)
contractual fulfillment can be demonstrated
outside organizations may be more neutral
central goal of acceptance testing is not to detect flaws but to verify adherence to requirements
Post acceptance
after acceptance, field testing is performed before international distribution
training methods, tutorial material, telephone help procedures, marketing and publicity can all be improved
the evolutionary development is forced, in the pre-release phase, through
system refinements may take place during use by many different and disseminated users
gradual sysem diffusion is useful so that problems may be solved with minimal disruption
major changes should be limited (and anticipated) to an annual revision
stable access to key resources (on the web)
gradual addition of improvements (patches)
Interviews
interviews with individual users can be productive since the interviewer may focus on specific issues of concern
focus-group discussions are also valuable to generalize comments
a small fraction of the user community is involved since all contacts are expensive and time consuming
yet contact with users leads to:specific & constructive suggestions
example
a large corporation conducted 45’ interviews with 66 of the 4300 users of an internal message system
these interviews revealed that the users were happy with some aspects of the functionality (the capacity to pick up messages at any site, the legibility of printed messages and the convenience of after-hours access) but- out of all users -
23.6% had concerns about reliability
20.2% thought that using the system was confusing
18.2% said convenience and accessibility could be improved
16.0% expressed no concerns
later questions explored specific features
as a result of this interview, 42 enhancements to the system were proposed and implemented
there were also earlier proposals but the interviews changed the set of priorities so as to better reflect the user’s needs
Continuous data logging
managers should be able to collect data about the patterns of
system usage
speed of user performance
rate of errors
frequency of requests for online assistance
guidance is provided for
the acquisition of new h/w
changes in operating procedures,
improvements to training
plans for system expansion
Consequence
the highest fequency error is a candidate for attention
the message could be rewritten
training materials should be revised
s/w could be changed to provide more specific information
command syntax could be simplified
staff should examine messages that never appear
if logging provides data for each command, each help screen, each database record, then changes to the human-computer interface can be made to simplify access to frequently used features
rarely used features should also be analyzed
at the US Congress legislation, some high-frequency terms like abortion, gun control and balanced budget could be entered into a list of hot topics
another advantage of frequently used features detection is that they help in optimizing performance and reducing costs
Privacy
logging is positive but may break into personal grounds
links to specific user names should not be collected
monitoring individual activity should be known to users (when and what will be done with the results)
manager and worker cooperation improves productivity
Online consultant
provides a very personal assistance
users feel reassured if they know there is a human available for help
such consultants are a good source for listing the problems met by users
some organizations offer a toll-free number for consultancy
AOL provides live chat rooms for discussion of user problems users type their questions and get their answers
Getting help
many groups maintain a standard electronic-mail address of staff@organization that allows users to get help
quick help at night from system analysts
e-mail can also be used to allow users to send messages to the maintainers or designers
an online suggestion box encourages to make productive comments
Suggestions
an online suggestion box invites comments, gets 10 to 20 a day including thoughtful ones as this:
I find as I get searching through the various Web pages...that I am left with an unsatisfied feeling. I have been sitting in front of the PC for close to an hour...and have been stopped and/or slowed due to items that can be directly related to web server design.
First off, the entry pages are too big and disorganized. Those links that do exist do not have adequate enough descriptions to direct a user to the information they desire. In addition, the use of a search engine would greatly facilitate sifting through the abundance of information that is thrown at the user with any one of these links.
Riguardo i riferimenti
Links should be short, sweet, and specific. Large amounts of material should not be included in one document on a busy server...
Breaking up these larger documents into smaller, well organized documents may seem to create an additional burden on programming. However, if intelligence is used in the creation of such systems, it would not take much.
An Internet directory service for personal names can be found at Knowbot Information Service with an invitation:
Place a compliment or a complaint in the KIS log file
Electronic bulletin board
or newsgroups are used by interface designers
open messages and questions are posted on both and are read/answered by interested people
newsgroups cover Human Factors and Ergonomics Society’s Computer Systems Technical Group
user newsletters and conferences generally contain: