Molly Liechty

False Alarms vs. Misses: Subjective Trust as a Mediator between Reliability and Alarm Reaction Measures

Research suggests that signaling system false alarms tend to affect operator compliance, whereas misses tend to affect operator reliance. Conceptually, false alarms and misses affect compliance and reliance via independent cognitive processes, assumed to be two types of trust. The purpose of this study was to test for these underlying processes using a subjective estimate of trust. Method: Using a sample of 44 college students, we tested for trust as a mediator between reliability (90%, 60%) and reliance, compliance, and response rate, for a false alarm prone (FP) system and a miss prone (MP) system. Results: As predicted, trust mediated the relationships between reliability and signal compliance and response rate, but only for the FP system. Additionally, the MP system more directly affected reliance, whereas the FP system more directly affected compliance. Applications of this work indicate that designing for trustable signaling systems may be more important for FP systems.

Role of an Anthropomorphic Agent in Environmental Decision Making

Computer agents can significantly impact the manner in which people perceive information and make choices. This study examined the effectiveness of an anthropomorphized computer agent (a Polar Bear) versus a simple text box at two levels of reliability on participants’ receptiveness to information about climate change and subsequent environmentally friendly behavior. Participants (N=110) answered questions about climate change while receiving the assistance of one of four computer agents comprising either an anthropomorphic agent (Polar Bear) or text box at 90% or 60% reliability. Results revealed that dependence on the anthropomorphic Polar Bear agent did not significantly differ from dependence on information conveyed via the Text Box agent; however, accuracy on the environmental quiz was greater for participants assisted by the Polar Bear agent under 90% reliability but lower than those assisted by the Text Box under 60% reliability. This study demonstrates that in some contexts the decision aiding advantages of anthropomorphic characters are selective and may be dependent largely on the agent’s demonstrated reliability at helping users reach their end goal.

The Effects of Affect and Inspection Duration on Decision Time and Confidence

A variety of factors modify decision making behavior. The current study examines how affective state and inspection duration impact decision time and decision confidence in a simulated luggage screening paradigm. Participants (N=200), from each of three “affect” groups—primed for anger, fear, or sadness— and a control group were tasked with detecting weapon targets with inspection durations of either two seconds (high time pressured inspection) or six seconds (low time pressured inspection). Results revealed a main effect for inspection duration on decision time, such that participants with more highly time-pressured inspections had longer decision latencies after the luggage image timed out. There were also main effects for inspection duration and affective condition on decision confidence, such that participants in the low time pressure group had greater decision confidence and participants in the fear group had lower decision confidence than those in the control group.

Investigating the Influence of Agency on Trust in a Collaborative Game-Based Scenario

This study is part of an ongoing investigation into the ways in which individual differences may interact with game characteristics to impact performance and subjective trust outcomes within virtual environments. In this study, researchers investigated the impact of team leader agency on trust and performance. Forty college students were told they were working alongside a computer-programmed team leader or a human team leader who provided instructions for twelve tasks in a first-person shooter game, Arma 3™. Results indicate that team leader agency may not impact subjective trust using this type of experimental manipulation, but that intrinsic motivation is related to trust outcomes. Results also indicate differences in the number of times participants reviewed the team leader’s task instructions as a function of agency. Implications for future research include measuring trust behaviorally and investigating whether game-based intrinsic motivation may mediate the relation between trust and performance.

An Assessment of Spatial Context on Eye Movement During a Visual Search Task

Contextual cueing is the implicit association of objects (or ‘cues’) in a visual scene due to repeated exposure, either spatially or semantically. These associations can aid people in detecting a specific target. The goal of this study was to investigate whether, and how, people utilize “distractors” as contextual cues during a visual target search and how spatial location of objects affects that association. Forty undergraduate participants performed a luggage-screening task in which spatial context was manipulated. First, participants were trained using 25 luggage images, each of which contained a target (i.e., knife) and a specific distractor (i.e., iPod). During the post-training session, participants screened 100 bags with a target base rate set at 50%. The bags contained either the distractor and the target (25 bags), the target only (25 bags), the distractor only (25 bags), or neither the distractor nor the target (25 bags). Participants’ fixation durations, dwell times, saccade counts, and scan paths were assessed. It was found that when the spatial context of the distractor and target were relatively close, participants appeared to encode the objects together, thereby improving search efficiency. By moving the distractor across the image from the target, eye movement patterns changed. The results suggest a higher activation threshold of the distractor when it was present adjacent to the target as compared to when it was moved farther away.

Memory and recognition of a non-target during a threat detection visual search task

Context plays an important role in visual search tasks. The ability of people to form implicit associations about the objects in the world around them not only assists them in focusing their attention but also in simplifying their world. The goal of this study was to investigate whether, and how, people utilize “distractors” as contextual cues during a visual target search. Twenty undergraduate participants performed a luggage-screening task, where they were asked to locate a specific target (a knife). First, participants were trained using 25 luggage images, each of which contained a target (i.e., knife) and a specific distractor (i.e., iPod). During the post-training session, participants screened 100 bags with target base rate set at 50%. The bags contained either the distractor and the target (25 bags), the target only (25 bags), the distractor only (25 bags), or neither the distractor nor the target (25 bags). Participants’ dwell times and fixation counts for specific areas of interest (AOI) were assessed across trial blocks. It was found that recognition of the distractor object increased across trials but the dwell time and number of fixations decreased as the experiment progressed. These results demonstrate that participants were able to recognize the distractor and form an implicit association between its presence and the presence of the target. Results also indicated that the presence of the distractor ultimately biased participant response, creating more “liberal” responses over time.

An eye movement analysis of contextual cueing effects

Contextual cueing is the implicit association of objects (or ‘cues’) in a visual scene due to repeated exposure, either spatially or semantically. Such associations can aid people in detecting a specific target more quickly and easily when it appears in a familiar context. The goal of this study was to investigate whether and how people utilize “distractors” as contextual cues during a visual target search. Ten undergraduate participants performed a luggage-screening task during which they were connected to an eye tracker. First, participants were trained using 25 luggage images, each of which contained a target (i.e., knife) and a specific distractor (i.e., iPod). During the post-training session, participants screened 100 bags with target base rate set at 50%. The bags contained, either, the distractor and the target (25 bags), the target only (25 bags), the distractor only (25 bags), or neither the distractor nor the target (25 bags). Participants’ fixation counts, saccade counts, saccade amplitudes, and scan paths were assessed. It was found that in the presence of the distractor, participants demonstrated fewer fixations and saccades as well as shorter saccade amplitudes than in the absence of the distractor. This was particularly salient in the absence of the target. The results suggest a higher level of search efficiency when the distractor cue was present, and less organized and more aggressive search pattern in the absence of the distractor cue. We contend that participants formed an implicit association between the distractor and the target and used this association to improve the efficiency of their visual search.

Impact of User Experience and Negative Externalities on Internet Search Patterns

An eye tracker was utilized to examine decision-making processes of experts and novices during an internet search task. Twenty experienced homebuyers and twenty-five undergraduate students viewed homes on a simulated real estate website. Several of the homes included physical properties that had the potential to negatively impact individual perceptions. These negative externalities were either easy to change (Level 1) or extremely difficult to change (Level 2). Each house image was divided into 6 separate “interest areas” in order to evaluate where participants spent the greatest amount of time during the visual search task. Dwell times and number of fixations were analyzed. Results revealed that experienced homebuyers demonstrated a more direct and refined visual search process than novice student participants. Experts had longer dwell times, and a greater number of fixations with fewer saccades in very specific regions of an image. Experienced homebuyers reacted to homes with a Level 1 or Level 2 negative externality present differently from novice students. It was found that the house or image being seen did temper this reaction. These results demonstrate important considerations when designing user-friendly web interfaces for users with varying levels of task experience.

An Eye Movement Analysis of Evolving User Preferences during Internet Search

Using an eye tracker we examined decision making processes during a simulated real estate internet search. Specifically, we studied discrepancies between “stated preferences”, or preferences that are revealed through verbalizations or answers on a questionnaire, and “revealed preferences”, or preferences that become apparent from an actual decision or choice. Participants viewed photographs of homes, similar to those seen on actual real estate websites. Average dwell time, fixation duration/counts, and saccade counts/amplitudes were compared to their stated preferences on home survey questionnaires and assessed by gender. This information was used to determine if discrepancies exist between stated and revealed preferences, what qualities on the website drew the homebuyers attention, how this may differ by gender, and ways in which these websites can more effectively be designed. In addition, we examined the effect of negative externalities, or physical properties that may affect an individuals internet search decisions. We manually altered several homes to reveal Level 1 externalities (or, properties that can easily be changed) such as pink paint on the wall, and Level 2 externalities (or, properties that cannot easily be changed) such as power lines in front of the house. Results revealed that men demonstrated a more aggressive search pattern than women, and the men had a greater number of saccades with shorter saccade amplitudes for each of the web pages seen. Dwell time, fixation duration, and fixation count were also found to change when participants were shown a home with the presence of a Level 1 (pink paint) or Level 2 (power line) externality, depending on gender. Data also suggested that a discrepancy exists between stated and revealed preferences. While a participant stated that they greatly disliked a room on the home specific survey, their dwell times, fixation durations, and fixation counts did not significantly decrease. These findings have implications for web design.