Handwriting recognizers occasionally misinterpret digital ink input, requiring users to compare their ink input and the recognizer output to identify and correct errors. Technologies like Anoto pens can make this error discovery and correction task more difficult, because verification of recognizer output may occur many hours after data input and may involve the verification of many documents. In this paper, we explore the design space for error discovery aids geared toward "out-of-the-moment" verification. We present three discovery techniques, a visual proximity technique, a multimodal technique, and a character manipulation technique, and analyze the performance of our techniques. Experimental results show that the visual proximity technique outperforms all others in number of errors caught, and is also significantly better than a control technique. This paper is the first experimental study of techniques that aid in the discovery of handwriting recognition errors.

Both handwriting recognition systems and their users are error prone. Handwriting recognizers make recognition errors, and users may miss those errors when verifying output. As a result, it is common for recognized documents to contain residual errors. Unfortunately, in some application domains (e.g. health informatics), tolerance for residual errors in recognized handwriting may be very low, and a desire might exist to maximize user accuracy during verification. In this paper, we present a technique that allows us to measure the performance of a user verifying recognizer output. We inject artificial errors into a set of recognized handwritten forms and show that the rate of injected errors and recognition errors caught is highly correlated in real time. Systems supporting user verification can make use of this measure of user accuracy in a variety of ways. For example, they can force users to slow down or can highlight injected errors that were missed, thus encouraging users to take more care.

Instant messaging is a prevalent form of communication across the Internet, yet most instant messaging services provide little security against eavesdroppers or impersonators. There are a variety of existing systems that aim to solve this problem, but the one that provides the highest level of privacy is Off-the-Record Messaging (OTR), which aims to give instant messaging conversations the level of privacy available in a face-to-face conversation. In the most recent redesign of OTR, as well as increasing the security of the protocol, one of the goals of the designers was to make OTR easier to use, without users needing to understand details of computer security such as keys or fingerprints.