Type of interaction and its goals

Using the Automated Teller Machine (ATM) is a human & Object interaction as well as human & human interaction. The goal is to do transaction with bank account(s), such as money withdraw, money transfer, payment and other banking services with ATM in a secure and safe manner. Money business is a serious business for most users, if not all. Psychologically users are very cautious and conscious about the cash value they entered, the accuracy of account number during money transferred, and the eyesight spying on their Personal Identification Number (PIN).


Tasks performed and types of interface used:

In the user side, tasks include self-identification, choice selection, transaction (of different services), and take the money with or without customer advice. The task flow will change slightly depending on different purposes of the users. In simple terms, the task flow starts with inserting of cash card, verification of PIN number, then a screen of options appears on display, user has to make choices and enter data such as cash value of withdrawal. This may lead to another screen of options and needs further selection and input. (As defined by Hugh Dubberly, Usman Haque, and Paul Pangaro, this is a learning system nesting a series of self-regulating systems with single loop.)  In the bank side, tasks include retrieval of account info, verification, authorization, transaction, printout of customer advice and return of cash card.

The interface involved is a combination of tangible and digital devices consists of card reader, keypad, cash dispenser, customer advice printer, display screen and of course the control system behind. Card reader initiates the PIN verification procedure after retrieval of account information. Keypad is used to enter PIN number, cash value and other account numbers. Digital display screen displays options and messages. Customer advice printer provides customer advice and receipts. Cash dispenser delivers cash to customers. The new ATM machine has evolved from tangible buttons to touch screen input, which is a digital interface.


Elements / features that alter task performance

In the old days, when doing money withdraw of transfer, customers have to fill in information such as account name, account number, cash value and sign on debit note, and then present the debit note together with the bank passbook to the teller counter. This involves steps of identification of bank account by passbook and verification of identity by signature. This procedure is simplified with ATM system where account information is stored in the cash card (EPS), all you need is your PIN number to access your account. The control of money withdraw and other simple tasks shifts from the teller back to the customer, and this sense of control is one of the major criteria and driving force in interaction design.

The lines stick on the ground, serving as the queue up signage, can subtly interact and direct users to line up in certain formations. Lines that separate different lanes for different machine indicate that customers should line up for individual ATM machine. You cannot cross the lane even when your queue is slow. If there is only one path for lining up, all users mutually understand that the user in the forefront has the access right to whichever ATM machine immediately available. This feature can help resolve the tension between users from the ambiguous uncertainty of who should be the next when there is an ATM available. This is not taught in school, but we are trained by common sense and experience, and somehow we have no problem interpreting the graphic meaning of those parallel or diverging lines.

When ATM security becomes a social problem, the bank and the government alert us with advertisement and warnings on ATM machine. Then human & human interaction comes into place and is added to the once purely human object ATM interaction! While we are interacting with the machine, we are also interacting with other customers behind us. We are highly affected by the way they stand and pose. Their slight movement will trigger our own gesturing if we suspect there is a danger of leaking of account information on screen or the PIN number we are typing on keypad. This factor turns our focus from tasks on screen to the task on location. The interface is our bodies and the goal of this interaction is to block the screen echoing to the movement of other users.


Elements / features that support or hinder the smoothness of interaction

For security concern, a housing is sheltering the keypad to hide the typing actions. This feature can ease the worry of users psychologically and also caters for physical challenged users, such as those who are carrying bags with one hand and cannot block the keypad. The bulging dot on key “5” also serve the function of orientation when users using the keypad but vision is blocked by their hands and the housing.

I had an experience at an ATM booth that housed both traditional ATM with large physical buttons and the ATM with touch screen interface. The customer in front of me invited me to use the immediately available touch screen machine and would rather wait for the traditional one. She claimed she preferred the tangible feeling of pressing physical buttons with the ‘click’ sensation. With this feedbacks she could ensure the tasks were done properly, and with those feedbacks she knows her transaction is safe. Other useful feedbacks include sound for each press, alert sound for returning card and most importantly alert for taking money from dispenser.

For the new touch screen ATM machine, the less tangible interface design drives users away. Using touch screen interface is a common worry for many users who have less experience with digital artifacts. The flat glass surface creates no differentiation for different “buttons”. The buttons are no more than graphic forms on screen, and the idea of “press” is very abstract and nearly unreliable when there has no actual press “down” response. May be by safety guidelines, the glass material of touch screen is exceptionally thick that has created a physical misalignment between the graphic button on display and the actual surface we touch. It is confusing about where to put our finger. This relates to the concept of Direct Manipulation that people feel they are controlling something tangible, not abstract. The benefit is that users more readily understand the results of their actions. This is critical in determining the level of confidence in serious business like this, with money involved.

To facilitate fast withdrawal activity and simplify bank operation, some preset cash values such as, $200, $400, $800 are listed on the menu for easy selection. This helps the users making clear choices of the important “financial” decision, and no need to worry about entering wrong cash value. Having said that a flexible system should allow users to enter user-specified amounts. In new touch screen interface, the function of “Express Withdraw” is added allowing user to set specified amount as preferred withdrawal cash value for future transaction. In principle, this function can facilitate the process and reduce significant steps in next transaction. However mistreatment of process of user input can create trouble. One obvious example would be that after entering the amount you want to withdraw, you will be asked to decide whether you want to set the cash value to “Express Withdraw”. But after choosing Yes or No, nothing happens. (Actually the color of the chosen button is highlighted while your fingertip is pressing and covering it!) After a long wait, you realize that you have to press the “Take Card” button to finish the process. Until then you are still not sure if the “Express Withdraw” selection is recorded or not. This feeling of uncertainty is definitely a bad user experience.

I start to think why money does not come out when you confirm the express value. Or after making that selection, the screen should refresh to the “Take Card” page as a clear indication of confirmation, and bringing up the next step. Or should that special “amount” be automatically listed on the cash value menu in next transaction if the system recognized that as a user pattern? I suspect this problematic treatment is the result of direct adaptation of the use of dialogue boxes in desktop computer where multiple options are contained in single dialogue box. However even with the same goal, user behavior is different in different circumstances; in this case user is standing in public space and operating with a finger only. More usability testing is needed to collect information for this subtlety.


Principles and strategies to support existing or create new user experiences:

Psychologically people have a need for control, but in an interaction, what we really want is just a sense of control, without which we experience tension and inadequacy. To acquire that, we need at least a sense of certainty, completion of outstanding things and understanding of how things work. In the terms of interaction design: the clarity of instruction and feedback mechanism, simplicity in task flow, and consistency of metaphor and processes.

Also the design of ATM machine does not cater for physical impaired users. This should be addressed, for example an ATM panel that adjusts height automatically for user in wheel chair.

To create new user experience, I suggest rethinking about the meaning and application of “Automation” in Automated Teller Machine. For security concern, we can employ finger print recognition technology to get rid of cash card & PIN number, as we are already accustomed to e-channel. And I believe that with build-in artificial intelligent, the system should be able to record, formulate and predict the routine transaction procedures using the ATM, and save the time and trouble of users repeating similar processes every time.

As advancement of technology, the shift from tangible to digital interface is in many senses inevitable. However experience can be designed resembling natural actions and responses with technologies such as skin sensation and immersive design, so as to fulfill the need of direct manipulation.



2009. “iPhone Human Interface Guidelines: User Experience”. Apple Inc.
Hugh Dubberly, Usman Haque, and Paul Pangaro (2009). What is Interaction? Are There Different Types?. Interactions magazine. From http://www.dubberly.com/articles/what-is-interaction.html
David Straker. The Need for: Control. Changing Minds. From http://changingminds.org/explanations/needs/control.htm