XXIV.6 November + December 2017
Page: 34
Digital Citation

Designing interactions with digital money

Mark Perry

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Innovations in computing and ubiquitous network infrastructures have driven the growing interest in digital currencies and payment technologies. Prominent examples include BitCoin, MPesa, ApplePay, and Venmo; in some cases, they have radically changed the ways in which we are able to transact with others. These technologies not only offer new ways of interacting with money but also can transform our understanding of how financial operations occur, how to make sense of financial information, and how these new forms of money or payment methods change our social interactions. Such developments present critical questions for HCI and IxD, including how we can support the design of new forms of technology that give value to money so that it is interactionally usable but also useful: credible as a form of financial exchange and understandable as a mechanism for economic transaction.

back to top  Insights


Bitcoin is a case in point for usefulness and usability. As it stands, the distributed ledger technology that underpins Bitcoin is highly unintuitive for non-experts. Its design is deliberately oriented toward payment privacy and inflationary stability, lending itself to two well-publicized primary uses for the currency: criminal behavior and speculative investment. Neither of these functions offers much of an incentive for ordinary users to exchange their existing currencies or payment mechanisms for Bitcoin. Because of its important role as an investment vehicle, much of the development effort for directly interacting with Bitcoin has been put into developing interfaces for managing currency-trading exchanges, but considerably less has been put into its use for everyday activity. The massively distributed computational architecture of payments processing for Bitcoin means that delivering proof of payment is relatively slow, again limiting its potential for more routine forms of exchange. These forces—and they all arise through deliberate design choices—conspire to mean that Bitcoin is not currently used much as a form of regular exchange. It seems unlikely to replace the regular forms of government-backed (known as fiat) currency that we typically use to make payments. Bitcoin is not unique in how these kinds of design choices affect the use and usefulness of digital money systems, but by understanding both the ways in which people use money and the ways in which different system configurations afford different opportunities for interacting with money, we can look to support different ways of transacting with money.

There is a huge diversity in the possible forms that money may take in the future. It is likely that a new ecology of systems will develop around niches in the financial infrastructure, each with its own opportunities for interaction design. However, there is an elephant in the room: the influence and interests of national governments, and in particular, the role of central banks in economic control and management. Their interests lie in ensuring financial stability via control of the money supply. Reductions in financial liquidity, impacts on inflation or deflation, opportunities for fraudulent behavior, and so on, have huge potential to damage national concerns, and so the regulatory environment for financial technologies is under continuous review and tight control. Nevertheless, central banks themselves are taking an increasing interest in developing digital currencies based on the distributed ledger technology (DLT) that Bitcoin is built on that integrate with their existing forms of fiat currency. That they are doing so has ramifications for all citizens and our daily lives due to the pervasive influence of money across our individual, social, and civic activities. Getting the design right in this instance is critical to much of what we take to be otherwise unremarkable and ordinary. Indeed, as Andrew Haldane, chief economist at the Bank of England, states:

Whether a variant of this technology could support central-bank-issued digital currency is very much an open question. So, too, is whether the public would accept it as a substitute for paper currency. Central-bank-issued digital currency raises big logistical and behavioral questions too. How practically would it work? What security and privacy risks would it raise? And how would public and privately issued monies interact?

These issues are of core concern to interaction designers as much as they are to economists.


Outside of the industrial-scale interactions carried out in the wider banking sector, the majority of the financial interactions that involve money are relatively small-scale. Buying a car or a house are important but irregular events for most people. Consider your own daily spending, for example; it may involve buying fuel, snacks, train fare, and coffee. Other common forms of interaction with money systems involve checking our bank balances, changing mortgage payments, tracking our investments, and organizing loans. The majority of our interactions with money are currently relatively small in value, or they involve limited monitoring and tweaking of existing arrangements. This is not to say, of course, that technology might not enable more radical forms of financial intervention that upend our current practices, but the point here is to illustrate that interactions around money permeate our lives and are frequently mundane rather than dramatic in their operation and consequences. Moreover, as economic anthropologists and sociologists have shown, such economic interactions are often heavily embedded in our social worlds (e.g., [1]). The simple example of paying for a shared meal in a restaurant illustrates this clearly: How the bill is split is often more than a simple fractional division, and needs discussion and agreement. Handing over the bill to the server may involve a discussion on the food and requests about the methods of payment or discounts accepted. We must also consider tipping and its consequences; manual handling of the payment media; making small talk with the server at the point of exchange; and the collection of payment receipts. These are not culturally or socially sterile activities, and changes to payment media or mechanisms are likely to affect the restaurant experience in some way. How any new payment systems are implemented is likely to have an impact on people's experience of their evening out, and the same will be true for a vast range of other events.

back to top  Design Opportunities and Constraints

The emerging financial-technology ("fintech") industry has latched on to the potential for disrupting the status quo for industry incumbents in financial services—it's one of the fastest-growing areas for venture capital investment. Yet while a huge amount of effort has been expended on opportunities for transforming the financial-services landscape, the impacts of these technologies often fall on ordinary users, for better or worse. Partly as a result of this, research around everyday financial interactions is beginning to receive tentative academic interest, with dedicated workshop sessions devoted to the topic in the HCI [2] and CSCW [3] communities. There is also a small but growing corpus of literature on the topic of financial interactions covering fieldwork (e.g., [4]), theory (e.g., [5]), and design (e.g., [6]).

One of the more obvious trends in interactions around money that presents an opportunity for designers lies in mobile and ubiquitous technology, where there are a number of HCI-relevant concerns. The scope of areas in which our financial interactions operate is also extremely wide, crossing many forms of mobile financial service. Interactions with fiat-payment technologies are maturing with a raft of tools and services to support this, but as we add alternative or cryptocurrencies to the mix, complications arise with managing exchange rates, regulatory differences, and mechanisms of transfer, all of which need to be handled on small screens and conducted at a socially acceptable pace. Traditional, and now peer-to-peer, financial services that have been previously managed in person or by phone are now possible on apps, with the potential for pulling on people's social media presence to develop credit ratings. From a different angle, mobile technologies also support financial tracking in a variety of ways, notably in allowing people to lifelog their spending behavior through "quantified self" approaches and then using algorithmic approaches to assess what effect their financial behavior is likely to have on their quality of life.

Given the ubiquity of money in our lives, transactional activities must also work over an intermittent wireless infrastructure that may involve bespoke hardware, and must often rely on the availability of power to all the transacting devices. While these may seem like technical challenges, the related design decisions also have interactional implications. The challenge here for designers is that solutions need to be developed that do not cut across their users' values, interests, and concerns. Alongside this, the effort costs and complexity of what are often necessarily elaborate financial interactions need to be handled so that users do not abandon them. As such, developing suitable mechanisms of feedback that engender trust; inform users about risk; build in and leverage social connectivity around financial interactions; support transparency about the underlying financial infrastructures and intermediary service providers; and utilize our everyday knowledge about money, perhaps building on aspects of its tangibility and materiality, are all important considerations for interaction designers.

We also need to acknowledge that we, as financial-services users, are not the only entities who interact with our money and financial information. Organizations—usually extremely well-resourced corporations—may have access to both our own accounts with them and aggregated user data. Supermarkets, utility providers, and banks, to name a few, have detailed knowledge about our financial arrangements and activities. Increased knowledge among organizations about our financial lives that can be leveraged by them in their own dealings has both positive and negative consequences for citizens. There are possibilities that this will lead to invasions of privacy and the potential for a degree of corporate oversight in our lives that may not be in our interests.

On the other hand, information gathering by organizations could be incredibly useful to improving the financial lives of citizens through the provision of customized services, as well as to the wider societal and national interests. Returning to the earlier example of a central-bank-issued digital currency, we are working on a project with the Bank of England, the Office of National Statistics, and the National Cyber Security Centre (CESG) to explore their design ("Smart Money"; http://gow.epsrc.ac.uk/NGBOViewGrant.aspx?GrantRef=EP/P032001/1). Such digitalization of U.K. fiat money would allow financial transactions to be tracked at varying levels of acuity, with control over access rights to the information. As we have found, for many organizations, flows of money are seen not just as ways of tracking financial movements, but also as ways of understanding national changes, such as those resulting from government policy, geopolitical shifts, and sociotechnical transformation. This allows for almost real-time access to economic data and supporting the use of data-mining techniques on a massively rich dataset. Systems like this are being explored by several central banks, and here too lie opportunities for interaction design (and HCI more broadly) to make this material available for practical use (e.g., interactive visualizations and dashboards), as well as to design systems that are publicly acceptable (covering trust and privacy concerns) and useful (e.g., allowing people to track and optimize their own spending) to citizen users of the digital currency. Getting the design of the money system right is of critical importance to the national—and indeed international—interest and may offer a unique position to HCI and UX in having transformational impact at a global scale. It also presents new challenges to the disciplines that HCI has worked with to date, engaging with policymakers, industry regulators, economists, and financial engineers, and a vast range of commercial and governmental organizations, each with their own interests at stake.

back to top  The Future of Digital Money

Our experience suggests a number of conclusions and design opportunities for the future of money and the role that interaction designers can play in developing it:

Financial sociality. Financial transactions are intimately bound up with social interactions. There is a rich anthropological literature on money that belies the view of money as an abstract means of financial settlement or capital exchange. We borrow, lend, pay, advise, check, gift, share, and display our wealth—all highly social activities. Transactional systems that fail to account for these activities when they are relevant are likely to offer a diminished user experience and consequently limited adoption. Digital financial interactions will almost certainly build on our social media footprint across a variety of aspects in leveraging our social capital and communicating our consumption patterns.

Transactional complexity. There is a tension in any design solution where there is complexity, and many financial technologies rely on complex infrastructures or employ multifaceted financial instruments even for simple transactions. Understanding what transactions actually involve is not trivial. Two plausible solutions are open to designers. The first of these is to provide full visibility into the transaction so that all aspects of its mechanics (including intermediaries, financial flows, risks, and so on) are inspectable. To do so through clear visualizations will allow users to understand and take control of their own finances, something that is becoming a plausible solution as banks disintermediate and financial information is made available with open banking APIs. However, utilizing this information may require both a sophisticated understanding of financial services and an interest in it by users, neither of which may exist. An alternative solution may lie in providing comprehensible models of people's personal finance, though not necessarily with a one-to-one mapping of correctness, to provide a simplified representation that does not mislead users in the actions they may undertake on the back of this knowledge.

Robust mobility. Future money and payments systems will become heavily used and serious contenders for replacing cash only if they support high levels of mobility. Yet one of the problems of mobile technology use is that it is dependent on battery life, device robustness, and network availability. Designing for systems in which digital payments can occur in the absence of multiple connected devices, yet with suitable transactional confirmation to both parties, is likely to become an interesting design space for transitioning toward a fully cashless economy.

The press around future digital money solutions suggests that the future of money lies in crypto-mathematical solutions, algorithmic trading, and frictionless forms of transactional engagement. Yet the history of money (e.g., [1]) would suggest that a focus on computation and infrastructure misses a huge determinant of its likely success. It is people, and the things they want and do, that gives value to designed things. In this respect, new forms of money and financial service are valuable only if they can be woven into the ways in which we live and act. Transactions are a form of interaction, and this places the success of future money systems firmly in the hands of interaction designers.

back to top  Acknowledgments

I would especially like to thank Jennifer Ferreira, Panos Louvieris, Leonid Ivonin, and Barry Brown for our discussions around the future of digital money.

back to top  References

1. Zelizer, V. The Social Meaning of Money: Pin Money, Paychecks, Poor Relief, and Other Currencies. Princeton Univ. Press, Princeton, 1994.

2. Kaye, J., Vertesi, J., Ferreira, J., Brown, B., and Perry, M. #CHImoney: Financial interactions, digital cash, capital exchange and mobile money. CHI '14 Extended Abstracts on Human Factors in Computing Systems. ACM, New York, 2014, 111–114. DOI: http://dx.doi.org/10.1145/2559206.2559221

3. Millen, D.R., Pinhanez, C., Kaye, J., Sardela Bianchi, S.C., and Vines, J. Collaboration and social computing in emerging financial services. Proc. of the 18th ACM Conference Companion on Computer Supported Cooperative Work & Social Computing. ACM, New York, 2015, 309–312.

4. Ferreira, J., Perry, M., and Subramanian, S. Spending time with money: From shared values to social connectivity. Proc. of the 18th ACM Conference on Computer Supported Cooperative Work & Social Computing. ACM, New York, 2015, 1222–1234.

5. Dahlberg, T. Mobile payments in the light of money theories: Means to accelerate mobile payment service acceptance? Proc. of the 17th International Conference on Electronic Commerce 2015. ACM, New York, 2015, Art. 20.

6. Vines, J., Blythe, M., Dunphy, P., Vlachokyriakos, V., Teece, I., Monk, A., and Olivier, P. Cheque mates: Participatory design of digital payments with eighty somethings. Proc. of the SIGCHI Conference on Human Factors in Computing Systems. ACM, New York, 2012, 1189–1198.

back to top  Author

Mark Perry is an interdisciplinary user studies researcher at Brunel University, with interests in mobile and ubiquitous technology, digital money, and the fintech industry. He has recently developed a Digital Exchange Toolkit with a peer-to-peer lender and a digital currency and mobile payments provider to support UX and infrastructure design. mark.perry@brunel.ac.uk

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