Online videos: The hidden curriculum

Abstract Introduction Dental undergraduates will access the Internet searching for learning materials to complement their training; however, open access content is not generally recommended by dental schools. This study aimed to evaluate how dental students are using online video content. Materials and Methods Students from eight Universities (Athens, Birmingham, Brescia, Cardiff, Melbourne, Paris, Sao Paulo and Valdivia) representing three continents were invited to complete a survey on their access and learning from online videos. Results International students behave similarly when studying dental content online. Of 515 respondents, 94.6% use the Internet as a learning tool. It was observed that videos are not frequently recommended during didactic lectures (9.6%). But many students (79.9%) will use YouTube for their learning which includes clinical procedures. Students will check online content before performing procedures for the first time (74.8%), to understand what was explained in class (65.9%) or read in books (59.5%), to relearn clinical techniques (64.7%) and to visualise rare procedures (49.8%). More than half of the students do not fully trust the accuracy or the reliability of online content. This does not prevent students from watching and sharing dental videos with classmates (64.4%). The content watched is not shared with teachers (23.3%) even when it contradicts what was learnt in the school (38.2%). Conclusion This study concludes that students regularly integrate open access digital resources into learning portfolios but are hesitant to inform their teachers about their viewing habits. Students wish to receive critical skills on how to evaluate the material they encounter outside their traditional learning space.


| INTRODUC TI ON
We are living in changing times where information can be accessed and created by everyone. The expansion of Internet access and the growing number of information and communication technologies (ICT), such as mobile devices, are responsible for promoting deep changes in the learning and teaching process. 1 The use of technology is now commonplace within learning environments. 2,3 Students are likely to access online content to complement their learning before or after a traditional lecture. 1,4 When students are searching for instructional content, Google is chosen as the default search engine over other search engines for most searches. 5 However, the ease of using the Internet brings new challenges and these are related to the quality, validity and reliability of the content. 6,7 Online content can be created and published by anyone without any peer reviews. 8,9 Infodemic is the term used by the World Health Organization to define the far-reaching, spreading overabundance of information, including false or misleading materials, that makes it hard for people to find reliable online content. 10,11 The scientific judgement of an undergraduate student may not be able to critically review online content sensibly. A solution is for peer review content to be created by their teachers which leads to the delivery of high-quality instructional online content. 9,12 The latest report from the Organisation for Economic Cooperation and Development (OCDE), based on data from the Programme for International Student Assessment (PISA), shows that less than a half of digital natives 15-year-old is not able to accurately distinguish between fact or opinion on the Internet. It was also demonstrated that many pre-undergraduates have difficulties in reading, exploring, interacting with online reading content as well as with task-oriented navigation activities. 13 For this generation, videos play a significant role in students' education. 13 The use of images, text and videos leads to enhanced learning. 2 Whilst video is a popular format, how they are designed and delivered may vary. 14,15 This also includes their use in flipped classrooms and video-based training of clinical procedures. 16,17 Videos stimulate learning not only with traditional lectures but also with clinical training. 18,19 Such learning is a natural progression for students who are familiar with searching and watching videos online for personal and scholastic reasons. 20 YouTube videos are considered as "How-to" learning tools. 20 Monthly over 2 billion logged-in users visit YouTube 21 and it has been observed that it is a source of health-related information for 80% of its users. 22 Videos are one of the most used and accessible electronic components and the content produced can be shared for free. [23][24][25] Dental schools seem to ignore this reality and do not provide open online content. Most studies published in scientific journals concerning the use of videos in dental education focus on the offering of teacher-created videos to their own students, under very specific and controlled situations. [26][27][28][29] As a result, online dental content is delivered by unreliable sources. 9 Understanding how students use online dental educational videos during self-learning sessions, out of the dental school, will be a major asset in integrating this behaviour into future methodological approaches. This study aimed to evaluate how undergraduate students are using online content as a complementary learning tool.

| Inclusion criteria
This international study compared the online behaviour of dental students from several schools in three continents when using Internet content as a complementary non-curricular learning tool. As a part of a European Union-funded project (number omitted), several dental schools were invited to collaborate. Eight schools, Athens, Birmingham, Brescia, Cardiff, Melbourne, Paris, Sao Paulo and Valdivia, participated in this study. Local coordinators organised recruitment, data collection and data input. School selection was partly due to previous research relationships and convenience. However, an additional rationale for country selection was related to their cultural background representation. For example, Australia and UK, despite their diverse ethnic composition, 15 place responsibility on the individual and individualcentred programmes, empowerment and personal enrichment. In contrast, countries like Chile are characterised by a more hierarchical societal structure, and a focus on the well-being of the group rather than individuals. 16 This would allow for the initial testing of the empirical hypothesis on the effect of the school environment in the use of online content as a complementary learning tool.
Dental students at each school were given an anonymous online survey. All students in the selected schools were invited to participate in this study. This study was reviewed and approved by the local University Ethical Committees at each University. Each respondent gave consent and had 4 weeks, after submitting the survey, to opt out of the research.

| Questionnaire
An online self-administered structured questionnaire was constructed by adapting and expanding previously published questionnaires. 1,24,30,31 The survey was delivered via Google drive using an account linked to a university email account. A short URL link to the survey was sent to the students, no personal data or email addresses were collected at any time. Each student was asked to create and keep a unique code in case they decided to opt out of the research.
The 24 questions were created in English, translated to Portuguese and Spanish and checked by native speakers. French, Italian and Greek dental schools opted to use the English version of the questionnaire. Closed-ended, multiple-choice questions were used. In some questions, the alternative "other" was offered. None of the questions was mandatory. The survey instrument was piloted, analysed and reviewed by invited dental teachers from different universities.

| Data analysis
Jamovi, 32 Bioestat 33 and SPSS 34 were used to analyse the data.
Descriptive analysis was used on specific questions. Inferential analysis was conducted for identifying factors (age group, year of the dental course and location of the dental course) associated with students' usage of, and opinions on, online educational content. Parametric or non-parametric tests (e.g. chi-square or Fisher's exact test followed by odds ratio, Phi and Cramer for nominal, and Kruskal-Wallis Mantel-Haenszel for ordinal categories), as required, were used to identify the association between study variables and socio-demographic and study characteristics.

| RE SULTS
In total, 515 students participated in the survey: Athens (n = 58), Birmingham (n = 23), Brescia (n = 15), Cardiff (n = 11), Paris (n = 138), Sao Paulo (n = 109), Melbourne (n = 112) and Valdivia (n = 49); the response rates varied from 3.0% to 30.5%. We received a similar number of answers from students of all years of the dental course. As expected, the majority of participants (79.5%) were 20-to 25-years-old with significant differences between locations (p < .01). Melbourne students were older than the others (p < .01; Table 1). By the year of study, in the Melbourne sample, most of the respondents were from the first 2 years of the course (p < .01).

| Finding video content
In all the participant dental courses, the large majority of dental students (94.5%) reported using Internet content as a complementary learning tool (Table 1). However, 5.3% only used when required, and another 4.45% reported reviewing Internet content once a week only. The most frequent reasons mentioned for using online content were clarification of facts (37.1%) and studying for the assessments (20.2%). About a quarter of respondents reported always checking for additional content (27.6%) ( Table 1). Those who indicated using the Internet "Only when is required" or "Once a week" or "Never" were grouped into an "Infrequent users" group. Melbourne participants were more likely to be in the infrequent users' group than those from other schools (OR = 2.94; 95% CI: 1.34-6.39). It also appeared that for each year of study the likelihood to be infrequent users decreased (OR = 0.75; 95% CI: 0.68-0.83).
When students were asked about the preferred device to access dental education contents, computer (69.7%) was the most preferred, in particular laptops, followed by smartphones (21.2%) and tablet/iPad (9.1%; Table 1). The majority of students indicated that they learned about education contents online from searching the Internet (53.8%). Another 34.2% indicated that the source of such information was teaching staff and the remaining 12.0% reported that the source of information was other classmates. There were no significant differences by year of study. However, there were TA B L E 1 Dental students' characteristics and use of Internet content for dental education In addition, when students were asked whether teaching staff recommend online videos as complementary content for their lectures, the majority (64.2%) responded "Never," "Hardly ever" or "Occasionally," or another 25.8% indicated that teaching staff recommends online videos "Sometimes." Only 9.6% (n = 36) responded "Frequently" or "Almost always." Consistent with the previous statement, students from Greece were more likely to indicate that they receive this information during classes frequently or almost al- Most students were not aware (54.7%) of the existence of an official YouTube channel from their dental school.

| Watching online content
Dental students have frequently (68.3%) learnt clinical procedures from online videos. As expected, students enrolled in the last years of the dental course have more chances of having seen clinical procedures from online videos than students from the 1st or the 2nd years (p < .001

TA B L E 1 (Continued)
found online with their teachers (Table 1). Students who learnt clinical procedures from online videos are almost three times more likely to share them with classmates (OR = 2.92; 95% CI: 1.95-4.38).
However, this was not the case with sharing content with teaching staff. Nonetheless, 30.9% of those who shared content with students shared this content with their teaching staff.
Few participants were "not very confident" or "not confident at all" of online contents' accuracy (10.4%) or about its relevance for the dental course (8.2%).
Nonetheless, the quality of online dental education materials was described as "Average" (44.2%) or "Good" or "Very Good" (42.3%). Still, the majority (77.9%) would like to receive information about how to check the reliability of online content (

| DISCUSS ION
In this study, the international panel of students who participated had similar use of the Internet as an extracurricular learning tool, despite their backgrounds and location. Although there were some differences by dental school location, it was not possible to identify any distinctive pattern by locality. Still, this is an empirical question with practical implications, worth to be answered. However, by years of education, there were significant differences. As expected, those in the final years were more likely to be frequent users of online resources.
Previous studies found that dental, medical and nursing students use a range of digital learning objects as non-official learning material. 24 Present findings would indicate that even during the so-called "normal times" (i.e. before the COVID-19 pandemic), the large majority of students across dental schools were using online resources as a complementary learning tool. Participants mostly used it as a "hidden curriculum" when they have doubts or as a source for additional content. Online content was also used when studying for the assessments.
Educational video platforms are appealing to students as they are more convenient and faster to access than having to check and read printed material. 35 YouTube videos are considered as "How-to" learning tools. 20 Google, but not Google Scholar, and YouTube were the first and second sites more frequently reported as accessed den- The importance of training and encouraging dental students to find reliable content and to discuss fake news during the dental course has been previously raised. 38 Dental students are not confident about the accuracy of online content but still access it due to their continuing desire to learn more about dentistry in their own way. The question remains as to how to develop the students' abilities to review and appraise such non-peer-reviewed material into their clinical actions. 35 In line with the literature, 24 students' preference was for video content. Dental students participating in this study found the availability of the Internet on their smartphones had a positive impact on their dental academic experience. Still, the laptop computer is the preferred device when studying dental content.

| Ways forward
Dental schools should be ready to create and publish more online video format content for their students using short videos (5-15 min) with narration, legends and timestamps. Timestamps organised according to subjects will increase students' engagement in your video and will give teachers the chance of knowing what their students' difficulties are. 8,[39][40][41][42] Accepting that students will access the Internet for content, dental schools should provide details on how to critically appraise and incorporate online teaching materials into their learning needs and differentiate facts and evidence-based information from just opinions or non-evidencebased content 13 As in any study, there were some limitations in conducting this international research, which needs to be taken into account when evaluating these results. For example, this study used selfreported data. In addition, the number of respondents varied, making generalisations and some comparisons difficult to make.
The sample size represented a low response rate. Response rates to online surveys about oral health are within the range of 2.5%-26%. 43,44 Additionally, this was a multicentric effort and the results were impacted by local practices of data collection. Other practicalities also moderated data collection. For example, EU

| CON CLUS IONS
Results from this assessment suggest that students are learning unofficial dental content from online videos, which include a range of clinical procedures. Overall, students from the dental schools included in the study seem to be hesitant to inform their teachers about their viewing habits but do regularly discuss the material in their peer groups. Dental students wish to receive training on how to evaluate the reliability of online content and incorporate it into their studies. Interestingly, these responses were quite consistent across the dental schools included.

CO N FLI C T O F I NTE R E S T
The authors confirm that there are no known conflicts of interest associated with this publication.