Not all transactions are created equal: the very last dollar in your wallet has a higher value than when there’s a stack of notes; an online transaction completed at home has different security implications than one completed in an internet cafe. Service designers have long recognized the need for extra checks and balances for ‘risker’ transactions – and these are typically reflected by levels of authentification. From a user’s perspective we’ve found it useful to frame transactions in terms of thresholds of concern and thresholds of alarm.

Some transactions fall below the so-called ‘threshold of concern’ – where it takes the user more effort to acknowledge and mentally process the transaction than the utility and/or satisfaction derived from knowing the transaction has taken place. For many people a small, frequent purchase such buying a newspaper might fit this criteria. At the other end of the spectrum, some transactions rise above the so-called ‘threshold of alarm’ and can significantly threaten the users quality of live and consequently users expect more checks, reassurance and feedback. Examples include large or highly time-dependent purchases. Between these two thresholds lies the so-called ‘zone of comfort’ – a space within which most everyday purchases take place, and within whose boundaries most of today’s service designs cater for.

It’s important to note that these thresholds are highly dependent on context, cultural and personal preferences: a transaction completed in the safety of the home might be well within the zone of comfort but when carried out in the context of a bus station might trigger alarm like behaviors; an everyday purchase that is normally considered trivial might be elevated to alarm status late at night when the user is close to running out of cash and there are no alternative ways to pay. There are cultural differences: a user can have different ingrained assumptions about risk depending on whether they are from a fatalistic or deterministic society; people from societies with a high level of social cohesion are more likely to value a trouble-free transaction rather than risk inconveniencing others.

What range of factors affect people’s perception of these thresholds? How can we help users manager their thresholds of concern and alarm?

Given people’s inability to accurately measure risk, how best to marry the users perception of alarm, with the system’s understanding of the same? And what tensions might occur between the provision of these features and, for example retailers desire for their customer to spend money?

-Jan Chipchase