%0 Journal Article %T Designing Tangible User Interfaces for NFC Phones %A Mikko Pyykk£¿nen %A Jukka Riekki %A Ismo Alak£¿rpp£¿ %A Ivan Sanchez %A Marta Cortes %A Sonja Saukkonen %J Advances in Human-Computer Interaction %D 2012 %I Hindawi Publishing Corporation %R 10.1155/2012/575463 %X The increasing amount of NFC phones is attracting application developers to utilize NFC functionality. We can hence soon expect a large amount of mobile applications that users command by touching NFC tags in their environment with their NFC phones. The communication technology and the data formats have been standardized by the NFC Forum, but there are no conventions for advertising to the users NFC tags and the functionality touching the tags triggers. Only individual graphical symbols have been suggested when guidelines for advertising a rich variety of functionality are called for. In this paper, we identify the main challenges and present our proposal, a set of design guidelines based on more than twenty application prototypes we have built. We hope to initiate discussion and research resulting in uniform user interfaces for NFC-based services. 1. Introduction Near field communication (NFC) technology [1] enables building tangible user interfaces [2] for mobile phones. The display and the buttons of a phone are no more in the main role, rather the phone is used as a physical object to touch other physical objects. Generally, users can start services and give commands to the services by touching objects in their local environment with their phones. In the case of NFC, the phones are equipped with NFC readers, and NFC tags are placed in the environment. NFC is a short-range wireless technology, compatible with the technology used in some proximity RFID tags and contactless smartcards. As the reading distance is short (about 5 centimeters), users can be instructed to touch tags, and the data read from tags can be interpreted as commands. Separate NFC readers are available as well, and the technology supports communication between two NFC readers and readers that emulate tags, but we focus in this paper on NFC phones reading NFC tags placed in the environment. NFC is being discussed as revolutionizing payment, ticketing, and advertising applications [3, 4], but we see much bigger potential for NFC-based user interfaces. NFC can bring good user experience to any situation in which interacting with a service requires knowing and performing a sequence of actions (like menu selections) or entering text (like URLs). All such information can be stored in an NFC tag and entered by a single touch. In a nutshell, NFC enables building extremely easy-to-use user interfaces that connect the digital and physical worlds: users can trigger actions and fetch digital content matching the situation at hand with simple acts of touching NFC tags with their mobile phones. %U http://www.hindawi.com/journals/ahci/2012/575463/