Pin-pad in the US Redesign
Error Analysis
Identify Errors
While conducting the interviews and observing how they interacted with the system, we were able to identify certain common errors that were made. We noticed that most of the errors made were slips rather than mistakes.
Figure 2.1. The red circle is referencing how the privacy hood is blocking the number “1” on the pin pad. Depending on the angle at which the person is standing, numbers “3”, “7”, or “9” could also be blocked.
Figure 2.2. A different example from another angle of the same privacy shield covering the number “7.”
Some users entered the wrong pin either due to small buttons that were too close together or due to the privacy hood obstructing their view, examples of which are shown in Figure 2.1 and Figure 2.2 above. In terms of the buttons themselves, occasionally there was not enough feedback for the user to know if they correctly pressed the button or not; there was no click or tactile feedback to know if their action went through, rather they just felt a ‘squish’ that didn’t really tell them anything. If the buttons were too small or too close together, they either missed the button they were attempting to hit or they pressed two buttons by accident. While most pin pads are arranged the same in terms of where the numbers are, it still helps to be able to clearly see where the buttons are to limit pressing the wrong one.
Some other common errors that users experienced were…
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Entering the wrong PIN
20% of our interviewees faced this issue. Since the pin-pad systems' buttons were small and insufficiently sensitive, many people found themselves entering incorrect Personal Identification Numbers (PINs) at the point-of-sale terminals. These buttons provided insufficient tactile sensation, which frequently resulted in entry errors.
Moreover, the pin-pad's design made things worse because it was difficult to fix a PIN that was input incorrectly; if the action buttons were not noticeable enough or too far apart from the rest of the pin-pad. The inconvenient placement and lack of responsiveness of the backspace or correction key caused further annoyance and delays for users attempting to finish their transactions. The middle arrow button on the pin pad allows the users to go back but
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Pressing wrong responses to on-screen prompts
Again, 20% of our interviewees faced this issue. When complying with on-screen instructions proved to be a laborious and annoying experience, users typically encountered a frustrating situation. The response buttons that were supposed to record the choices made by the user were frequently too small or lacked distinct borders, which resulted in unintentional selections and prolonged prompt navigation times.
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To make things even more annoying, these buttons' touch sensitivity was not precisely calibrated, requiring several tries before a single selection could be made.
Figure 2.3. The red circles indicate interactive prompts on the screen. Since the buttons are also blue like the color of the screen and quite small in comparison to the rest of the screen, the buttons are not only hard to notice but also hard to interact with.
Figure 2.4. From interview 13. The pen is missing from the system causing the user to assume that the screen is a touch screen, though later on had to find the pen hanging down from the side.
In three cases, the users expected the screen to be a touch screen, though later had to find a pen that could interact with the screen as the pen was not in its designated spot but rather hanging down to the side. While a user could assume that the screen was touchscreen, this error could also come from a capture slip if they more recently used a touchscreen, or a description similarity slip if another pin pad had a similar design and was touchscreen. This badly designed interface turned an easy task into a tiresome and frustrating affair, which frequently left users feeling unsatisfied with the overall user experience.
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Chip insertion and card swiping error
20% of our interviewees faced this issue. Because of the design of the card reader, users often made mistakes when inserting chip-enabled cards or swiping their magnetic strips at checkout points. Consumers frequently have trouble deciding whether to swipe their card along the magnetic stripe reader or enter it into the chip reader slot. The absence of obvious instructions or directional signals on the screen, which should have led them through the transaction procedure, added to their bewilderment.
Figure 2.5. There is a lack of obvious signifiers as to how to communicate with the user where to insert their card. On further inspection, there is an icon on the bottom side. However, the bottom side is not angled so that a standing user can see it. Since there is no other signifier, like a light, users are even more confused as to where to insert their card.
Figure 2.6. Close up of the right side of the pin pad, the swipe icon is circled in red. This icon is small and not in an attention-catching color that is easily missed.
This led to a trial-and-error technique that not only delayed transactions but also increased a sense of dissatisfaction and inefficiency at the point of sale. Many found themselves trying both activities in an attempt to figure out the exact way necessary for their specific card.
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Don’t know which side is the correct way to swipe the card due to the lack of signifier icons
10% of our interviewees faced this issue. Customers typically faced a frustrating challenge when trying to swipe their cards: they were unsure of the proper orientation for their cards due to the lack of visual indicators or signifier icons on the pin-pad POS. Users frequently resorted to a guessing game, swiping their cards in various ways in the hopes of finally hitting upon the correct one, as there were no graphical signs to indicate whether to swipe with the magnetic stripe facing upwards or downwards.
Figure 2.7. The red box circles the area to swipe to pay. Of note, while the section is in a different color, there is no icon to communicate with the user which direction to swipe their card or the orientation as to which the user needs to swipe their card.
While from the conceptual model of the designer, it might be obvious to swipe the metallic section of the card into the pin pad as that is where the information is “coded”, general users might not have that same amount of knowledge. This would lead to knowledge-based mistakes as the user would not have enough information nor the same conceptual model as the designer to understand in which orientation to swipe their card.
The pin-pad POS's lack of clear instructions resulted in several unsuccessful tries, which notably slowed down the payment process and raised the aggravation levels of consumers who were only attempting to finish their transactions.
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Don’t know where to tap to pay, or whether tap pay was available (screen or another area)
20% of our interviewees had this issue. Customers have been greatly confused by the inconsistent design of different pin-pad POS systems, especially with regard to the 'tap to pay' feature. Users are frequently left wondering where to hold their card or device to start the payment in the absence of regions that are clearly indicated or that are globally standardized for contactless payments.
Figure 2.8. There is no clear icon indicating where the user can swipe their card. In the case of Interview 12, the user incorrectly tried to tap on the screen as that is what they did most recently at another store (capture slip), though the real area of payment was the left lower corner.
Figure 2.9. The area to tap is circled in red. From interview 11, there was confusion from the user as to if the icon was there to indicate that the pin pad accepts tap payment, or if that area was actually where they were supposed to tap their card. Due to this, they tried to tap on the screen first as a similar pin pad allowed them to tap on the screen (description similarity slip), but afterward, they moved their card to the corner and this error with extra movement caused a more frustrating overall experience.
While some systems have a defined place elsewhere on the terminal that is frequently unmarked, others need a tap against a specific area of the screen. Customers may find themselves tapping their card multiple times in an attempt to hit the correct sensor due to the lack of clarity and uniformity. This causes embarrassment but also messes with the checkout process.
Error classification
We can classify the above errors into two different categories: Slips and Mistakes. Where slips are subconscious mistakes that are committed either due to physical action, memory lapse, pattern of behavior, etc., mistakes happen because of a lack of correct conceptualization towards the goal the user is trying to act out. These can be for a multitude of reasons, such as a lack of knowledge or also due to memory lapse. Overall, the slips we identified tended to be capture slips and memory lapse slips. The mistakes we identified tended to be knowledge-based mistakes due to a lack of knowledge about how the pin-pad POS system was set up.
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Slips:
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Pressing wrong responses to on-screen prompts: Clicking through the prompts too fast because they are tedious and accidentally pressing something you don’t mean to, such as whether or not to round up and donate or whether you need bags or not when you yourself know full well whether you need bags or not.
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Entering the wrong PIN: because your fingers went to the wrong buttons due to differently sized or formatted pin-pads across stores.
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Mistakes:
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Tapping on the wrong part on the pin-pad POS in order to complete payment due to confusion with where to tap.
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Pressing wrong responses to on-screen prompts: because you are not sure what they mean or understand them wrong.
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Chip insertion and card swiping error.
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Don’t know where to tap to pay, or whether tap pay was available (screen or another area)
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Don’t know which side is the correct way to swipe the card due to the lack of signifier icons
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Entering the wrong PIN: due to the fact that buttons are hard to press, and so you are not sure how hard to press them in order to correctly enter the numbers.
Patterns and Trends
The Last interview question that we asked the interviewees to rank the importance of certain aspects of the pin pad system. This way, we could get a better understanding of which parts of the pin pad POS to change and which parts might not be of importance to the user.
Figure 3.1. Stacked bar graph showing which ranking interviewees put for certain aspects of the pin pad.
Through this graph, we can see that 13/16 interviewees ranked ‘security’ as the most important aspect, which is why later on we focus on keeping the security aspect in our redesign. The category most commonly second-ranked with 8/16 interviewees ranking it second was the ease of finding where to pay. Next was visibility at 8/16 ranking it third, we would improve this through increasing the size of the screen. Fourth-ranked was button sensitivity on 10/16 and fifth was the amount of payment options on 11/16.
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The trends observed through interviews highlight a strong preference for contactless payment methods, particularly the "tap" feature, which has gained widespread popularity. Many people have seamlessly integrated these payment methods into their daily routines. The choice to use this method of payment may have a lot to do with the fact that users tended to struggle mightily with card swipes and chipping not working.
Figure 3.2. Pie Chart showing the percentage of people that preferred each payment form. From this chart, we can see that the payment method preferred is to tap their card or phone to pay. This could be due to efficiency for the user where they don’t have to locate the acres to insert or swipe.
The majority preference in favor of tap pay may also be largely attributed to the fact that mobile phones have become an indispensable part of daily life for the majority of individuals. Preference for Contactless Payments: The "tap" feature, exemplified by services like Apple Pay, has emerged as the favored method for making payments. Users seem to appreciate the speed and simplicity it offers.
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Another important trend we found was that the majority of errors were committed in the second task, as shown in below Figure 3.3.
Figure 3.3. Bar chart showing the number of errors committed during each stage in the tasks we asked interviewees to perform. Task 1 was to initiate payment, Task 2 was to make the payment, Task 3 was to respond to prompts, and Task 4 was to confirm payment went through.
Figure 3.4. Bar chart showing the types of errors committed within Task 2.
More specifically we found the following distribution for the types of tasks that were committed within the Task 2 stage, as shown in the below Figure 3.4.
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This altogether leads us to the realization that not only were most errors committed during the payment stage itself, but also that the largest difficulty users had with the physical pin-pad POS system was issues having to do with the pin-pad number pad itself.
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Another trend we noticed was that, when ranking different aspects of POS systems that were important to them, users almost always ranked security first. This is an important insight because it means that when making design decisions that have trade-offs, we should never sacrifice security.
Trade-Offs
One of the trade-offs for the pin-pad POS system is security and usability. Implementing strict security measures, such as complex authentication processes or physical privacy shields, can enhance data protection but may lead to a less user-friendly experience. For example, users may find it less safe when there is no cover as they insert their PIN. This is the reason many pin-pad POS Systems have a small hood covering the corners of the pin-pad. This small hood makes it more difficult for people to see what you are typing. However, at the same time, many have some slight difficulty pressing the buttons due to this hood over the pad covering numbers. Another example that shows this trade-off is that some of our interviewees responded that the small size of the Pin-pad POS makes it easier for them to keep their privacy since they are then able to shield the pin-pad with their non-typing hand. However, many interviewees also stated that the screen itself is too small and this causes other errors when viewing the post-payment prompts on the screen.
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Another trade-off is the simplicity of options and again, user-friendliness. Simplicity of options includes both simplicity of payment options and simplicity of the post-payment prompts. Some users who generally prefer tap pay preferred that the POS not have any physical card swipe or pin-pad whatsoever, since it makes things look cluttered and confusing. Additionally, some users felt that the number of prompts provided after payment was already completed was annoying, and that coupled with a poorly designed screen made it extremely difficult to finish the payment without making errors or becoming frustrated at the software. However, with fewer options, there would be less opportunity for users to use different preferred payment methods. For example, if the pin-pad POS system did not have a swiping area, people using an EBT card would not even be able to use their payment method.
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Another important trade-off for the design of POS systems is whether or not increases in user friendliness also increase the cost of the POS system itself. This is important because, at the end of the day, companies and businesses are looking to profit. However, in our redesign, we chose to make a trade-off towards a higher cost and higher user-friendliness due to our belief that greater user-friendliness may not have an adverse cost on the business since it might allow people to check out faster and come back more often.