Usability - Desktop

Example - The Blankchester City Web Site

The requirement is originally defined as:

"Blankchester is a cathedral city in the centre of England. It is an historical city with tourists visiting but also has modern industry. As part of the "Blankchester - a New Millennium" project, Blankchester City Council have commissioned a web site to raise the profile of Blankchester. The project will also contribute to the "Blankchester - access to all" equal opportunities project. It is anticipated that it will be used by tourists and by residents for information about Blankchester, and by local tourist information officers for finding information when answering telephone enquiries. The web site may be accessed via Internet browsers, or for local authority employees via the proposed Intranet. In the Intranet the local authority employees will have access to additional information and pages. The site may be used simply to browse information and additionally to make bookings for tourist accommodation and events. The website shall be designed with reference to the requirements of the Disability Discrimination Act, and shall therefore comply to WAI and RNIB guidelines."

A particular difficulty with setting requirements for a web site is correctly identifying the tasks. The only safe way is to find out what users actually want to do with the site (perhaps by investigating how people use other similar sites, or by user-based evaluation of very early paper prototypes). The IT department visits two other Tourist Offices, at Dashmouth-on-Sea and Cipher Hills, to see how the tourist officers used the site and to look at their site feedback. This information is fed into the validation and review process. The validation and review of these requirements gives rise to a context checklist, part of which is shown below:

Figure 1 context checklist:

Blankchester City web site - Context Checklist
Goals for this system: raise the profile of Blankchester, provide access to information ("access to all" campaign), provide booking system for accommodation and events in the City.
Users
Type		Tourist	Resident		Tourist Information officer
Skills and knowledge No / low / good Web/IT knowledge No / low / good Local knowledge No / low/high previous experience of Hotel booking		ü ü ü	ü ü ü		ü ü ü
Attributes (people) with sight / hearing / language / mobility difficulties / with other special needs / without special needs		ü	ü		ü
Smoking / non smoking With children / without children With pets / without pets		ü ü ü	ü ü ü		ü ü ü
List of tasks Browsing general information / tourist attractions / events Hotel/accommodation/events searches and bookings Browse additional intranet pages (for space in the example this is not expanded)		ü ü N/A	ü ü N/A		ü ü ü
Task checklist	Browsing	Searches		Bookings
Goal User Blankchester City	Finds information Profile raised	Finds information More rooms let		Room / event ticket More rooms let Larger attendance at events
Output	List of general information meeting personal criteria	List of hotels meeting personal criteria		Booked and confirmed accommodation
Frequency	5000 hits per day	5000 hits per day		500 per month
Duration	4 clicks max traverse.	Hotel search 1 click from home page		book hotel less than 1 minute from selection
Environment in which the software/system is to be used	Tourist office - Tourist Information Officer's PC - IE5 Tourist office / library public PC IE5 Other user - could be a range of browsers - test for IE5 + IE4 + Netscape4 Design note: ensure text only version of the site available. (Note: this is a newly identified requirement and must be fed back to the designers)

Note: A context checklist may also consider side effects, flexibility, physical/mental demands, dependencies, safety, and criticality.

The requirements, context checklist and paper layout of the screens is inspected, using heuristic evaluation checklists. The context checklist is then used to draw up tests using equivalence partitioning and boundary value analysis for users against environment.

Figure 2 Partitions

ACTION/TASK: Book a hotel room
Test case	New Partitions tested	user type / skill / Attribute (people) / environment	Actions	Expected outcome
1	1, 4, 5, 14, 16, 20, 23, 24, 27	A tourist with sight difficulties and a guide dog, little web experience, and no local knowledge, no children, uses the library public PC. She wants a smoking room. English is not her first language.	Browses for a 4 star hotel and books it	Able to book a room (smokers) at the 4 star Jupiter Hotel, which welcomes pets and guide dogs. Site / PC has tools to offer information in audio and in languages other than English
2	2, 6, 7, 8, 10, 11, 13, 15,17,19, 30	A local person with good local knowledge and good IT /web skills but no experience of hotel booking uses their own PC (Netscape 4) to book hotel rooms for a visiting party of friends. No Special needs	Browses for hotel in the £80-100 per night range and books hotel	Able to find and book Mars hotel, able to find and print map to Mars hotel
3	3, 9, 26, 32	A tourist officer with little web experience, good local knowledge, previous experience of hotel booking, no special needs, at own PC, takes enquiry and booking from tourist in office, while being interrupted by phone calls	Browses for hotel in the £40-60 per night range and books hotel	Able to find and book Saturn hotel, able to answer additional questions, provide map to Saturn hotel. No timeouts.
4	12, 28	A local person with good local knowledge and good IT /web skills but no experience of hotel booking uses their own PC to book hotel rooms for a visiting party of friends. Hearing difficulties, own PC (IE5)	Browses for hotel in the £80-100 per night range and books hotel	Able to find and book Mars hotel, able to find and print map to Mars hotel. Major information given visually.
5	16	A local person with good local knowledge and good IT /web skills but no experience of hotel booking. Person with mobility difficulties (wheelchair and arthritis in hands and wrists) Uses library PC to book a hotel room for a friend	Browses for hotel in the £80-100 per night range and books hotel	Able to find and book Gaia hotel, able to find and print map to Gaia hotel. Height and angle of PC suits needs. Keyboard and pointer device easy to handle and control without pain.
6	31	A tourist officer with little web experience, good local knowledge, previous experience of hotel booking, no special needs, at own PC, takes enquiry and booking from tourist in office, without being interrupted by phone calls	Browses for hotel in the £40-60 per night range and books hotel	Able to find and book Saturn hotel, able to answer additional questions, provide map to Saturn hotel.
7	18, 21, 22, 25, 29	A tourist whose child has an allergy to animals, no pets, little web experience, and no local knowledge, her own PC (IE4) to book a no-smoking room	Browses for a 4 star hotel and books it	Able to book a no-smokers room for self and child at the 4 star Cathedral Hotel which has a no pets policy and check for allergy aware hotels

Scenario name:	Enquiry for hotel
System:	Blankchester web site	V0.9	Date: 12-1-2000
Goal of test	The goal of this use case is to test the basic enquiry job, where a (potential) tourist is searching for accommodation
	Description
Context	This is core functionality, so this is an important test of a frequent usage function
Actors	Any user may use this function : Tourist - low web user, Tourist - high web user, BCC Tourist officer (trained), Local person - low web user, Local person - high web user
		Checked	Comments
Preconditions	The PC is on and functional The user is connected via their normal ISP The user is online and looking at the web site home page and has chosen to use the drop down selections
Description of main flow	2 star in walking distance of cathedral 1. the user clicks on Hotels 2. the user clicks on 2 star 3. the user clicks on location - cathedral 4. the user clicks on Find
Expected results	the system displays 2 hotels details - "Wardens House" and "Deans House" and the user can print or save the information
Alternative flows	The user wants to see 3 star hotels - all in Blankchester 1. the user clicks on Hotels 2. the user clicks on 3 star 3. the user clicks on find
Expected results	the system displays a drop down list with all 3 star hotels (15 on test database)
Failure conditions	No booking conformation number displayed Wrong rating hotels displayed
Additional attention points	Note response times

	Time in job (years)	Windows experience (years)	Internet / web site experience (years)	Attitude to computers/ web (1-7)^*	Gender	Age group
1	5.5	3.5	0	6	F	20-35
2	0.8	2.1	0.8	1	F	20-35
3	2.1	2.5	2.1	3	M	20-35
4	4.9	3.5	1.5	2	F	36-50
5	0.7	0.7	0.7	2	M	20-35
6	1.6	2.1	0	3	F	36-50
7	4.3	1.4	0	4	M	36-50
8	2.7	4.6	2.7	4	M	20-35