An example of task-centered design

This example illustrates an (incomplete and sketchy) example of steps 1-3 of your assignment on task-centered system design.

Task centered design: Background

The Situation

• A small library has contracted you to build a computer system that will let librarians and their assistants deal with routine requests by the library clients. The computer(s) will be situated on the checkin/checkout counter.

Section 1: Tasks and Requirements

Introduction: Background to the system

• This is a small library that serves a town of about 10,000 people
• About 500 people use the library each day, although this varies.
• Its holdings include books, CDs, and cassette tapes
• The library already has a computer system that collects, in a database, all its holdings and a unique bar code number. All holdings already have a bar code label on them.
• The library also has a computer system that allows its clients to peruse its holdings (these computers are set up on booths in the middle of the library). As this system is satisfactory, and will not have to be replaced.
• However, the computer system used by librarians and their assistants is badly out of date and awkward to use. This is the one that will be replaced in this project.

Section 1: Tasks and Requirements

Introduction: Expected Users

• The users of the system are experienced staff: the librarians and library assistants.
  (library clients will not be allowed to use the system)
• Library staff are all experienced at all routine library operations
• The library expects all its staff to be trained on system use, either formally (through a course if necessary), or by apprenticeship (where staff will learn on the job from other proficient staff members)
• Library staff are currently all experience with PCs and the usual suite of applications that run on Window’s 95

Section 1: Tasks and Requirements

Introduction: Work Contexts

• Librarians do many chores, such as re-shelving books, tidying up the library, helping clients find books, sorting new holdings, and so on
• One of their chores is to work the counter, which is the emphasis of this project.
• The library moves from quiet to quite busy periods
• During quiet periods, the staff do their routine chores, and only go to the counter when a client approaches it.
• During busy periods, a staff is always at the counter, and calls other staff to the counter when the line-up starts growing
• During busy periods, lineups routinely grow to about 3-5 people, with longer lineups being rare
• However, people rarely have to wait more than 5 minutes before being served

Section 1: Tasks and Requirements

Introduction: Work Contexts

• The library moves from quiet to quite busy periods
• During quiet periods, the staff do their routine chores, and only go to the counter when a client approaches it.
• During busy periods, a staff is always at the counter, and calls other staff to the counter when the line-up starts growing
• During busy periods, lineups routinely grow to about 3-5 people, with longer lineups being rare
• However, people rarely have to wait more than 5 minutes before being served

Section 1: Tasks and Requirements

Introduction: What the envisaged system will be used for

The system will handle routine counter work, which now includes

• helping staff answer customer requests (either face to face or by the phone)
• telling clients their status ie what books they have out, what fines are pending, and so on
  
• checking library holdings in and out
• checking for late fines and informing clients
• collecting fines
• providing new library cards
• checking for expired cards
• renewing library cards
• phoning people who have overdue books

Section 1: Tasks and Requirements

Introduction: System constraints

• The library already has a well maintained computer system that contains all the holdings in a reasonably fast database. The library does not expect to change this system, and ask that your system link into it.
• The library also have several modern PCs running Window’s 95, already located on the counter. They expect that your system will be built on that platform
• There is a very modest budget for additional equipment, if needed.

Section 2: Concrete task examples

What you have to do

• for details on what makes a good task, read the assigned readings, the assignment and Appendix 1 carefully
• go the work site (if possible), and
  • interview staff/end-users
  • observe people doing real tasks

Section 2: Concrete task examples

Some examples garnered by talking to the library staff and observing them work

• Joan, a regular and experienced library employee, is working behind the counter. Mary, a regular library customer brings three books to the counter and asks that they be checked out. These are: <3 books should be listed here>. Mary does not have her library card. Joan finds Mary library number, checks out the books for her, and reminds Mary that she has some late fines to pay. Mary says she will pay for them next time. Joan gives Mary the books, and Mary leaves.

Discussion.

• This is a fairly routine task, as validated by Joan. Books are checked out, and the client is reminded of late fees. It also illustrates some working practices. For example, most clients do not have their cards, and expect librarians to look them up. This is acceptable library policy. Similarly, staff can choose to allow customers to defer paying their fees.
• Joan is also a typical system user, while Mary is a typical client

Section 2: Concrete task examples

• Joan’s next client is Saul. Saul is a regular library patron, well known to staff, and is somewhat notorious for exceeding book checkout limits, returning books late, never having his library card, and accumulating library fines. He is returning 3 books (2 which are overdue) <list here>, and Joan starts checking them in. One of the books, however, is missing its bar code number. She looks up the title, checks it in, and sets it aside for repair.
• While she is doing this, Saul brings 8 books to the counter and 5 audio tapes <list here>. Joan starts checking out his holdings. , She notices that he has reached the maximum level of $10. books. She tells Saul about the fine, and he pays it. After four books, she notices that Saul is max’ed out on the allowable books and asks Saul if she can check the rest out on his son’s account, and he says yes. She continues to do so on his son’s account until all books are checked out. Saul then asks if he can renew any books that are overdue. 3 of them are, and Mary does this.

Discussion.

• This is a complex task that contains many situations that, while less routine, are still important. In particular, it contains some elements of the library policy (eg dealing with maximum fines), some workarounds (eg, max’ed out accounts), and some less routine situations (eg, missing bar codes).

Section 3: Tentative list of requirements

• Absolutely must include:
  • rapid check-in and check-out of holdings
  • lookup of customers
  • status of customer holdings (eg, books checked out, books overdue, fines)
  • ability to clear fines
  • ….
• Should include:
  • …
• Could include:
  • …
• Exclude:
  • ...
• Discussion
  • Why items are in those categories