In-Depth Activity Comments
When doing this activity you will probably be surprised at just how little people know about how contactless cards and smartphone apps like Apple Pay and Google Pay, work (unless they have worked in a bank). A main reason being that, as far as they are concerned, a contactless card is there to provide them with a quick way of paying for goods and services they are purchasing. They just need to know where to place it and how to wave it in front of the card reader. While the transaction is being processed, a green light shows on the terminal display. It will then show that the amount has been approved and has been taken from your account. People don't need their PIN except sometimes it will ask them to verify their identity. It is only when unexpected things happen (e.g. it does not activate, they get charged twice) that they may start to wonder how the contactless card or a smartphone Pay app works. The information that is sent between the contactless card/Pay app and terminal uses radio-frequency identification for making secure payments. The card has an embedded chip in it that emits radio waves allowing consumers to wave their card over the payment terminal at the point of sale. This system picks up the signal and processes the transaction. The maximum amount you can pay for something using the card varies from country to country, for example, in the UK it is currently £100. The reason for this is to prevent fraud. Because no signature or PIN verification is typically required, contactless purchases are often limited.
You can use your contactless card any number of times a day. Many banks, however, will set a daily spending limit. They will receive confirmation that their payment has been sent. The amount that can be sent is limited (e.g. up to £250 each day). Card readers are only supposed to recognize cards that are no more than 5 cm from the scanner but some customers have reported being charged while their wallets or purses were still in their pocket or handbag. Contactless payments are covered by most banks anti-fraud guarantee. A card can only be used a few times before the bank asks for a PIN number so it is unlikely that it will ever be used for purchasing large numbers of goods.
Some of the questions asked are difficult to answer. For example, how does the card work? All you can see is the wave symbol on the card. You have never been told what is written on it. You have to infer from your knowledge of banking how smart it is. Most of us are unlikely to have thought much about many of the questions asked. So, we make inferences on the spot from our limited knowledge about such systems. This is what we mean by ad hoc reasoning. We also frequently use analogies, e.g. 'well it is like any other smartcard, such as an Oyster Card, in an attempt to explain. Some of these inferences maybe appropriate and others not. What did you find when you asked other people? You may have discovered that their explanations were quite different. It is quite common for there to be variability between people's explanations of the same system. Also did you find that people used incorrect analogies, superstition or even bizarre models to explain their understanding? People can be quite creative when forced to provide explanations when they have no idea! Another issue that is important to think about is whether you really are eliciting a person's mental model, when asking such questions. How do you know what they say reflects the knowledge they use when interacting with a device? This question has taxed researchers for many years and there is a whole literature on how to elicit mental models and how to determine whether they are really the knowledge representations people use in their activities.