Unexploded landmines have severe post-conflict humanitarian repercussions: landmines cost lives, limbs and land. For deminers engaged in humanitarian landmine clearance, metal detectors remain the primary detection tool as more sophisticated technologies fail to get adopted due to restrictive cost, low reliability, and limited robustness. Metal detectors are, however, of limited effectiveness, as modern landmines contain only minimal amounts of metal, making them difficult to distinguish from the ubiquitous but harmless metallic clutter littering post-combat areas. We seek to improve the safety and efficiency of the demining process without introducing an inviable replacement for the metal detectors. Instead, we propose and evaluate a novel, patternbased visual support approach inspired by the documented strategies employed by expert deminers. In our laboratory study, participants provided with a prototype of our support tool were 80% less likely to mistake a mine for harmless clutter. A follow-up study demonstrates the potential of our pattern-based approach to enable peer decision-making support during landmine clearance. Lastly, we identify several design opportunities for further improving deminers' decision making capabilities.

understand and address the grievances that often lie at the heart of insurgencies."Despite the high cost of recent wars, we are fortunate to live in a time of relative peace. There hasn't been a war between major powers for more than 60 years, and the number of inter-and intrastate conflicts is at an all-time low. This gives us a great starting point to at least try to maintain armed conflict at this low level, if not reduce it even further.

To become proficient at landmine detection, novice deminers need to master several kinds of skills: the proper physical operation of the metal detector, the interpretation of the metal detector auditory feedback, and the abstract skill of constructing and interpreting mental representations of the "metallic signatures" produced by the buried objects. This last skill is particularly useful for safely dealing with mines laid out in cluster configurations, where their metallic signatures overlap and thus a danger exists that a deminer might either miss some of the mines or incorrectly assess their exact positions. However, some novice deminers find it challenging to learn how to properly reason about metallic signatures. We have developed Petals, a system that explicitly visualizes a trainee's metal detector operation history on a training task as well as the edge points of the metallic signatures that the trainee collected. Petals enables instructors to supervise multiple trainees at a time, to assess their performance at a glance, and to provide immediate and specific feedback both on the correctness of their final judgements about the number and positions of landmines, and on the process through which they arrived at their conclusions. The results of our field evaluations at the Humanitarian Demining Training Center showed that both the instructors and the trainees found the system a valuable addition to the training course. The results of a controlled study demonstrated that trainees who had access to Petals during training made significantly fewer errors (6% error rate) on relevant tasks during the final exam (which was conducted without Petals) than trainees who did not have access to Petals during training (those participants had a 21% error rate).

The increasing ubiquity of computing devices coupled with recent empirical research on the factors that affect the likelihood of conflict provide HCI researchers with new opportunities to conduct research on interactive systems designed to prevent, de-escalate and recover from conflict. Approaches used by HCI researchers in this field have included the use of a multi-lifespan research initiative to support peace and reconciliation after genocide, CSCW to facilitate communication, visualization to help detect landmines, and calming technology to support individuals desiring interactive systems that scaffold non-violent interactions. In this workshop we plan to further explore these ideas and discuss existing and future challenges.

Post-conflict landmines have serious humanitarian repercussions: landmines cost lives, limbs and land. The primary method used to locate these buried devices relies on the inherently dangerous and difficult task of a human listening to audio feedback from a metal detector. Researchers have previously hypothesized that expert operators respond to these challenges by building mental patterns with metal detectors through the identification of object-dependent spatially distributed metallic fields. This paper presents the preliminary stages of a novel interface -Pattern Enhancement Tool for Assisting Landmine Sensing (PETALS) -that aims to assist with building and visualizing these patterns, rather than relying on memory alone. Simulated demining experiments show that the experimental interface decreases classification error from 23% to 5% and reduces localization error by 54%, demonstrating the potential for PETALS to improve novice deminer safety and efficiency.