On the basis of the heuristic evaluation, the change in deadline, and weeks of development and testing, I have updated the requirements:
Primary (“Must-haves”)
- Colour-coded tile screen comparing current weather in different cities
- Basic set of weather variables to select from
- City-sorter algorithm to arrange the tiles N to S, W to E on the screen
- Updating mechanism – automatic and manual
- Settings to change the units and update frequency
- Map-based interface for changing the selected cities
- Europe-wide coverage
- Android compatibility (e.g. for resolutions) and design consistency (icons, menus, settings etc.)
- Easy to use – clean interface, help documentation
- Gestures to change weather variable on home screen, to complement the buttons that do this too
- Local storage of data in an SQLite database, updated from a web server which will hold all possible data in a MySQL database, updated from an API.
Secondary (“Should/Could-haves”)
- City summary to show all data for a single city – accessed from clicking tile
- Quick view of all cities available and their current data, sort-able by name or value
- Multiple user-defined city collections for the main screen so > 9 cities can be saved
- Searchable cities on a map and non-map interface
- Option to display rank data (amongst all 100+ cities) as well as the absolute values.
Postponed (“Wants”)
- Drag-able tiles to enable custom arrangement
- Pre-set city collections for major countries, and “random set” option to generate a collection
- Animation (tile rotation, colour transitions)
- Ability to change time-frame of data (max/min/yesterday…)
- Extensive, customisable set of weather variables
- Ported to Windows 8 platform
- Ported to iOS platform.
Removed from previous requirements
- Reliable data – bad sites to be blacklisted
- A mechanism for users to report bad data
- Global coverage
- Graph-based view.
Notes:
- The handling of bad data requirements have been removed after extensive testing, including with users, showed them to be redundant.
- Global coverage and a graph-based view were deemed to be outside the scope of the app so could conflict with its purpose.
- Several secondary requirements have been demoted owing to time constraints.
- The gestures requirement has been promoted following the consideration of Norman’s principles (see that post for detail).
- Heuristic evaluation and my own testing revealed the benefits of the “quick view of all cities data…” requirement. It will be added if time allows.
- A few other minor features have been thought up and added to either the Secondary or Postponed list.