The first set of studies aimed to determine how transmission delays of various lengths impact team communication and performance under different media conditions. Findings then informed the design of medium-specific communication protocols. Their feasibility for space missions was assessed in two analog environments, NASA’s Human Exploration Research Analog (HERA) and NASA’s Extreme Environment Mission Operations (NEEMO). A complimentary laboratory study was conducted to examine whether the availability of protocols enhanced remote team members’ communication and task performance during periods of communication delay.
In a companion laboratory study investigators explored the impact of transmission delay on team communication and task performance in relation to varying task demands and different communication media. Spatially distributed teams of three collaborated in a computer-based task environment and communicated either by voice-over-internet or via a texting tool. The micro-world for the study was AutoCAMS 2.0 which simulates the life support system of a spacecraft and requires team members to monitor and control different subsystems, and to diagnose and repair failures. Each team was required to perform procedural and problem solving tasks during one synchronous and one asynchronous flight segment with a 5-minute one-way delay in communications transmission. Each flight segment lasted for 90 minutes. In order to guarantee the requirement of communication and collaboration on the experimental tasks, task-related expertise concerning diagnostic and repair procedures was differentially distributed among team members. The Flight System Engineer (FSE) received extensive training on AutoCAMS systems, diagnoses, and repairs, and had access to a comprehensive reference manual. The two Pioneer crewmembers were given basic training on AutoCAMS and were instructed to contact the FSE for guidance on diagnosis and repair whenever a failure occurred on their system.
In all NEEMO and HERA missions, communication delay occurred on consecutive mission days. Communication between crew and Mission Control was delayed by 5 minutes or 10 minutes one-way. In some simulations communication medium was limited to voice or text on a given day with transmission delay, or the crewmembers could choose their communication medium. Copies of the communication protocols were given to trained participants at the start of a mission to serve as a reference aid on days with a communication delay. Surveys were administered throughout a mission asking participants to rate the effectiveness of the protocols and their interactions with mission control, and in a final survey to provide feedback on individual elements of the communication protocols.
Analysis of the AMO data provided first insights into the effects of transmission delays on team communication. Specifically, investigators observed that transmission delays disrupted the timing and structure of turns such as communications by different team members. Communications by different speakers co-occurred (i.e., step-ons in which team members talked over each other) or were out of sequence (i.e., related turns by partners did not follow each other as one partner inserted a turn before the addressee could respond to the initial contribution). Both types of disruptions likely increased team members’ cognitive workload and jeopardized common ground. Step-ons compromised mutual understanding insofar as parts of a message were inaudible and required additional turns to repair which, given the transmission delay, were likely associated with considerable costs both in terms of time and workload as partners had to wait for critical information and keep track of concurrent tasks.
Analyses of team performance revealed that transmission delay impacted time required to initiate a successful repair and more importantly, that its effect varied by communication medium. When communication was delayed, teams used a comparable amount of time to repair system failures, irrespective of the communication medium used. However, when communication was synchronous, voice teams outperformed text groups. Likewise, teams’ accuracy in performing system repairs was influenced by communication medium. Overall, teams communicating by text undertook more incorrect repairs than teams communicating by voice.
Analysis of FSE/Pioneer communications revealed that communication delay influenced both the rate of turns by team members and the length of their contributions. Team members made fewer but longer contributions when they communicated under time delay than when no time delay was present. Moreover, these effects were more pronounced for teams communicating by voice than those communicating via text. This finding suggests that team members using text may have been more concise than team members in the voice condition. However, subsequent content analyses of Pioneer Crew/FSE interactions during transmission delay revealed that text communication was also associated with an increased potential for misunderstanding. Text teams were more likely than voice teams to split up related information and present it in separate turns. Related communications by distributed team members were also further apart in text- than in voice-based communications. Text communication also included more threats to common ground, in particular missing responses and anaphora (i.e., terms whose meaning could not be established within a turn but depended on information provided in preceding turns).
NEEMO and HERA
Trained crewmembers generally rated protocol elements and conventions as fairly critical to ensuring effective communication during asynchronous conditions. Very high ratings across crews for several items—providing a topic, using a log to track related messages, and announcing complex or critical messages—reflect the value of protocols for keeping track of message threads. Compliance with the protocols was also high as crewmembers generally followed the protocols in their communications on mission days with a transmission delay.
Overall these findings suggest that asynchronous communication may be facilitated by protocols that aid conversational partners in keeping track of conversational threads and the temporal sequence of messages. Results from this study led to the development of a communication training module that can be used to prepare crewmembers and members of Mission Control for the challenges of communication delay. Moreover, the communication protocols not only target how to speak or write during asynchronous conditions but also point to specific technological solutions.