Notifications are used in most platforms to inform users about important (and not so important) application events or changes in state, for example, when another user has changed a shared document. Depending in the platform and user settings this may take the form of a pop-up, auditory alert, change in a status bar or message via email or other channel.
Ideally the pace of the notification should reflect the pace of the timeliness required by the event, a reminder of a meeting the following day could be via email, whereas the imminent arrival of a train (and hence need to go to the platform) might require an auditory alert. Also the notification should ideally arrive at a point of time and with sufficent context that the user can take action. Sadly, this is rarely the case with a mixture of the important and irrelevant, urgent and non-urgent with no obvious distinction; at best this wastes the user's time and interupts the current activity, at worst it means the user learns to ignore notifications thus obviating their purpose.
Also known as: notification-based systems