Wednesday, May 4, 2011

Usability Blooper: PIN point of sale terminals ridiculously slow

In my opinion, the time consumed by point of sale (POS) terminals that require entry of a PIN is usually excessive.

There seem to be several different sequences of interaction with these devices. Here is a common sequence of events for credit card POS terminals. The user's actions are numbered, and amounts of time used are given in red.

1. The customer inserts their card.
    Typical system delay following this: 2-7s
    The terminal presents the amount of the purchase and asks the customer whether this is OK.
2. The customer takes 3-5s to think and clicks OK,
    Typical system delay following this: 2-7s
    The terminal asks the user to type their PIN and press OK
3. The customer takes 2-5s to do what is requested
    Typical system delay following this: 1-3s
    The system says 'please wait'
    Typical system delay 3-10s (processing transaction)     The system says 'Approved. Please remove card'
4. The customer takes 1-2s to read this and remove their card.
     The system prints the receipt to be given to the customer, taking 5-10s

Total interaction time 19-49s.

There are 12-34 wasted seconds here, including one unnecessary customer interaction. The only partially excusable cause of delay is if the POS terminal is in a rural area and has a dial-up network connection so actually has to dial up. Any other delays are purely due to slow technology either in the interface between the POS terminal and the cash register, the back-end at the bank, the network between the POS terminal and the bank, or the printer. In today's world, where Google can search results from the entire Internet in less than a second, these kinds of delays are unacceptable.

Note that for debit cards there would be an additional step of selecting the account, which adds a few more seconds to the above. There are also many variants of the above, including ridiculous terminals that ask for additional confirmations. Furthermore, since POS terminals all differ, users have to carefully read what is required at each one, that slows down everybody's thinking time. Many times I have started to type my PIN, and then realized that the system is actually asking me some other question.

Here is my suggestion for a standardized interaction:

A. The user inserts their card.
    Reasonable system delay following this: 0s

    The terminal instantly presents the amount of the purchase, and asks the user to
     enter their PIN or to press Cancel if the purchase amount is wrong
B. The customer takes 2-5s to think and type.     Reasonable system delay 1s (processing transaction)

    The system says 'Approved. Please remove card' and immediately prints the receipt.
C. The customer takes 1-2s to read this and remove their card.

    The system prints the receipt to be given to the customer, taking 3-7s

Total interaction time 7-15s for a credit card. Even for a debit card, the system in step A could default to the first account or usual account used (e.g. chequing account) and say 'Press SAV' to use a different account. In other words, the time taken or most debit card interactions could be the same.

Other user interface experts could quibble with my suggestions:
  • They might complain about having a longer prompt with an 'or' in it in step A. It is true that such prompts, upon first reading, are slightly more complex to understand. However users would get used to it very quickly if my suggested interaction was standard.
  • Another concern might be that users would never bother to check the amount, so might pay an invalid amount if all they have to do is enter their PIN (as in step A), rather than OKing the amount (as in step 1). However, how many of us deeply think about the amount before pressing 'OK'? How many of us read the paper chit before signing it in a signature-required interaction? I think if the amount to be charged was in a large font, this would not be an issue.
  • A third concern might be that if users are not required to remove their card before the receipt prints, then they might leave their card in the machine. However this could be rectified by having the POS terminal beep if the user does not remove their card after a few seconds.
The key is that in my interaction, all you ever have to do is check the payment amount and enter your PIN. This is quick, simple and should be the standard. No user confirmation should be necessary, other than entering the PIN, which serves as its own confirmation.

Lets think about the cost of all the wasted time. And to be charitable, lets assume the time wasted only averages 15s per transaction. That means for establishments selling one or two items at a time (coffee shops, convenience stores) where the remaining parts of the transaction could take less than a minute, they may need to add 25% more staff. It might require 10% more staff in the average establishment. That could cost $200 million in Canada per year, and $2 billion in the US. Also consider the extra time that customers take waiting in line, which can delay people from getting on with their work.

The old signature-required interaction also took a long time, and had much more paperwork as well. Now that credit-card purchases are going fully electronic, however, there is really no excuse.

For an earlier post on credit card issues click here.
For earlier posts on usability click here.

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