A serious challenge for teaching in these times of health crisis lies in the transfer of face-to-face teaching to online methodologies while continuing to deliver effective learning as efficiently as possible. Like many other education publications, this Journal has recently dealt with this issue [¹-³]. Shifting face-to-face simulation to online simulation poses some difficulties but the limitation on clinical practice for health science students imposed by the Covid-19 pandemic has made it even more necessary than was previously considered. Although there are currently irreplaceable components of clinical simulation, such as the physical examination of the patient, other skills, especially non-technical ones, can be taught online with resources and face-to-face simulation tools [³].

As has happened with other teaching methodologies, the Covid-19 health emergency has challenged institutions to develop appropriate materials and simulation experiences to enable a shift from face-to-face simulations to effective and stimulating online approaches [⁴]. Many experiences with online simulation, virtual reality and related approaches to medical education have been reported. Less information is available about the reproducibility of learning outcomes when face-to-face simulation is transformed into online simulation.

Both forms of simulation should meet two conditions: recreate real scenarios [⁵] and obtain students’ emotional involvement [⁶]. The most realistic simulation resource for competences directly related to the patient is the ‘simulated patient’ and online interaction with him/her has proved not only feasible but also useful, since telemedicine has become a competence of health professionals that nowadays must be taught [⁷].

At the student level, the face-to-face or online simulation sessions are usually held in groups. While one or two students are performing, the rest closely observe so as to share the experience, which will lead on to a reflective learning process. During the debriefing, the teacher facilitates the process of reflection and observes the reactions of both the students who perform and those who are watching [⁵]. Synchronous and mediated sharing of experience is essential for simulation learning, both face-to-face and online. Extensive information has been published about several aspects of online simulation activities, including descriptions of different activities and their outcomes, as well as of online debriefing strategies [⁵,⁷,⁸]. Less information is available about what happens during synchronous online simulations or what ‘rules’ should govern students in their role as observers during these activities.

Digital learning experiences differ from face-to-face experiences in some important ways, so some adjustments are required to maximize students’ learning [²,⁹,¹⁰]. Although different alternatives have been recommended during the virtual sessions regarding the use of cameras, microphones and even clothing [²,⁷], we asked our observing students to turn off their cameras when the simulation began and not to use the chat box. We considered these rules essential to enable the student/s performing the simulated action to concentrate and engage with the simulated patient/scenario [⁵]. However, this approach does not allow the teacher to monitor whether the observing students are paying attention to the online simulation activity or if they are discussing things with one another in parallel using other chat boxes.

During the first wave of the pandemic in our country (second quarter of 2020), we developed online simulations for the schools of physiotherapy and medicine of our university. A total of 10 face-to-face formative simulations were adapted to the online format and 6 online summative simulations were created; all of them included real-time interactions with simulated patients. The simulations developed for physiotherapy form part of an 8-week course aimed at improving clinical reasoning, decision-making and differential diagnosis that includes 5 rounds of simulation covering 12 scenarios in different clinical contexts. The formative simulations developed for medicine are intended to cover cross-curricular core competences such as communication, patient safety and critical thinking; the learning objectives of these online simulation sessions were identical to those of the face-to-face simulation programs from which they were adapted.

After the first round of simulation, an anonymous survey asked students in the physiotherapy course what they did when their cameras were off during the simulation; 42 (66.7%) responded. The vast majority of these students reported that they used instant-messaging apps (WhatsApp, Telegram, or others) to communicate with each other, discussing their profession more than they had ever done before. We did not expect these results, which underline the potential for students’ collaborative work and reflections in online simulation to enhance learning, but also highlight possible drawbacks associated with unsupervised or unguided interaction. As said earlier, reflective practice is a fundamental principle of the simulation methodology, and it is based on authors such as Kolb and Schön [¹¹]. In our approach to online simulation, the observing students are invisible. This invisibility allows those carrying out the simulation to focus but deprives teachers of any control over what observing students do when they are supposed to be observing the scenario. We call this phenomenon the ‘black hole’ of online simulation, a metaphor from astronomy sometimes used to refer to something that sucks everything in, making it disappear. So, when students are in the ‘black hole’ nobody knows what happens, because teachers cannot know what the audience is doing during the simulation unless they take specific steps to discover it.

In replacing face-to-face simulation with online simulation, we aim to achieve equivalent or superior learning efficacy [⁶,¹²]. Regardless of the media used to provide instruction, teachers need to ensure that students achieve their learning objectives and competences efficiently [¹³]. Reflection is a cornerstone to learning in simulation, and teachers must design content to facilitate reflection by students. Individual students need to reflect on their own experience before receiving input from others in the debriefing. Thus, it is essential to address how best to engage students individually during online simulation. Based on our experience, to maximize the learning efficacy of these observing students, teachers should be able to channel their comments through a parallel collaborative network without interfering with the student doing the simulation. Using apps or platforms such us WhatsApp or Telegram or creating group meetings through teams parallel to the online simulation could be a strategy the teacher can employ to enhance ‘controlled’ participation and facilitate ‘reflective-thinking’ while observing. Students are remarkably skilful at combining technology and probably online teaching, and online simulation in particular must explore parallel pathways of communication to ensure teaching remains student-centred [⁵,⁷].