# Design and Applications of GLANCE: GLanceable Alarm Notification for a User Centered Experience
## 3 Results of the 1 st Macro-Phase: The GLANCE Project
### Second Iteration: Dealing with Multiple Alarms
#### 3.2.2 Evaluation and Learning
In particular, we built a series of 40 screenshots covering a broad range of possible scenarios and critical configurations compatible with the display size (e.g., intra-NE simultaneity, inter-NE simultaneity up to six NEs involved, contiguity of very similar or very dissimilar colors) and in this case we used ad-hoc synthetic scenarios in place of sequences extracted from the alarm log to test specific risky combinations. After an internal pilot test aimed at tuning the timing of the administration of screenshots in the sequence, the actual laboratory-based test took place with ten recruited users (an appropriate sample of subjects for the purpose of the test [62]. _Experiment sessions_. In total 10 (four female) experienced users of PCs with Microsoft Windows aged 22-48 (AVG = 30.8; M = 26) took part in the study on a voluntary basis, recruited among students and personnel of the university campus (five participants were Master students, one participant was a PhD student, two were laboratory technicians, and two were from the administrative personnel). Participants were invited singularly to the lab, welcomed, and informed about the objective of the study. After a brief description of features and behavior of the GLANCE display the test began. Each participant was presented with the screenshots of the sequence, with each screenshot displayed for a few seconds to evaluate what users grasped at a glance (Figure 7 illustrates some of the scenarios shown to test participants). After each screenshot, users were asked to report the number of alarms in the synthetic component for each color (actually, this request is even more demanding than the actual task in a real situation, in which low severity notifications may be ignored with little harm). Overall, each user session lasted approximatively 30 min. ResultsResultsResults are consistent with [PERSON]'s study on the channel capacity and on \"the magical number seven, plus or minus two\" [63]. In the case of _intra-NE simultaneity_ (Figure 7a) correctness of responses dramatically dropped from above 80% to 40% moving from eight to 10 simultaneous alarms (screenshots were made progressively denser with an increase of two additional subareas in the synthetic component at each new step), while nobody provided a correct answer with 12 simultaneous alarms. The steep discontinuity in performance from the 8 case to the 10 case makes it reasonable to fix 8 as threshold for the case of intra-NE simultaneity (see Table 6). It is worth noticing that since alarm markers are displayed from left to right from the most severe to the less severe ones, consistently with the typical behavior of short term memory, the number of most severe alarms was always correctly remembered, being these the first in the list, as well as in the 10 and 12 cases. In the case of _inter-NE simultaneity_, two cases must be considered, depending on whether each NE is the source for at most one alarm or more than one. As to the glanceability of the synthetic component, the former case leads back to the intra-NE simultaneity case, while for the latter it is necessary to test different configurations corresponding to an increasing number of involved NEs (Figure 7b illustrates the cases of two/three/four distinct NEs). Since for the inter-NE case, the notifier visualizes alarm information considering in sequence one NE after the other, it is possible to analyze the synthetic component of each NE area independently of what happens in the other NEs involved. In the case of two NEs (illustrated in Figure 7b) we achieved the same performance results as in the intra-NE case (correctness above 80% up to 8 subareas and harsh discontinuity for the 10 case), and we hence fixed a threshold of 8 subareas (see Table 6). With more than 2 NEs, because of the increasing limitation of the available space estate for each NE in the synthetic component the steep degradation of recall performances occurs before than in the two NEs case, leading to a threshold lowering (Figure 7c,d show the cases of three and four NEs, respectively).