ents in future encounters with unfamiliar technologies. We create new mental models that we carry with us, to help us predict how other software and devices will work when we encounter something slightly different or new. Our ability to learn and use something new is then (again) contingent upon our ability to apply antecedent experiences in productive ways. We “run the model,” and we hope that the new technology operates according to the same rules that controlled the previous experience. In this fundamental way, our ability to use new technologies is contingent upon our prior experiences with other technologies.

But new technologies don’t always follow the same principles and patterns as previous ones, and this is the other way in which they are contingent. They change. They take one form today, another tomorrow. They use language in unexpected ways and deploy idioms and metaphors inconsistently and confusingly. It becomes difficult to refer to antecedent experiences in order to learn how to use something new. There is too much incompatibility between our previously formed mental models and the new system before us. An online game that appears to allow direct manipulation in fact requires a memorized sequence of keystrokes. A line of text that looks like a hyperlink actually requires a double-click to activate. A cus-tom-designed scrolling widget uses unconventional horizontal arrows in addition to vertical ones, thus making it difficult to access much of the content in an application. This kind of contingency in the technologies we use

does not further our understanding. Rather, it makes it more difficult to learn new technologies because it introduces inconsistency and randomness, making it impossible to predict the effects of our actions. It hinders our ability to develop reliable mental models about the workings of the digital world in which we live and work.

No Is Yes:

Press Cancel to Proceed A common example of the problem of contingency can be found at the checkout aisle of any grocery store or discount superstore. For several years now, people who use credit cards for purchases in such places have encountered a confusing interaction: After swiping our cards, we are prompted for our Personal Identification Number (PIN) to authorize the transaction. Observing our bewilderment, helpful clerks will ask the now familiar question, credit or debit? Answering “credit,” we are then instructed to press the cancel button and proceed as usual. Sure enough, pressing cancel sends the process request to the bank and moves the transaction along, culminating in a request for an ink or digital signature. Sometimes pressing cancel leads to an intervening screen that again offers the choice of credit or debit. Today “Press Cancel to Proceed” is everywhere. Those of us who habitually pay with credit cards have accommodated this new aspect of reality to our mental representations of how the systems work. We now do it automatically, without bothering the cashier. But this is not legitimate new knowledge that will help users of information

systems with other interactions. In every other situation, cancel means abort the procedure, stop, don’t do anything.

Banks and stores have many reasons to favor (and default to) one form of payment or another. But the inconsistency in this interaction from store to store makes it clear that customer confidence and understanding about the transaction process is not high among them. The fact that “credit or debit” often really means “signature or PIN authorization,” but the consumer rarely is informed of the implications of each, is further evidence that these systems are not designed to meet the user’s needs [ 3]. To further complicate matters, some banks encourage customers to choose credit at checkout, even when using a debit card. That is, they encourage signature-based authorizations over PIN-based ones, because signature-based authorizations are more profitable for the bank issuing the card. But they often disguise this fact with arguments about security and purchase protections.

One credit union, for instance, offers this advice on its Visa/ ATM FAQ page: “Take advantage of all of the benefits of your VISA Check Card by always selecting ‘credit.’ The funds will still be withdrawn directly from your checking, and you will receive the purchase protection of VISA, a service that does not apply if you choose ‘debit’ [ 4].” In other words, choose credit when you want debit. For those who use a debit card instead of a credit card as a way to control spending, it is probably clear enough that their debit card will subtract funds from the checking

[ 3] Sullivan, Bob. “Debit Or Credit? Here’s The Answer.” The Red Tape Chronicles. September 19 2007. <http://redtape. msnbc.com/2007/09/ paper-or-plasti.html>

[ 4] Michigan State University Federal Credit Union <https://www. msufcu.org/knowledge_ searchm.php?mnuccid= &l=&x=&action=expan d_question&questid=145 &deptid= 3&catid= 5&ke yword=>

September + October 2008