How does sustainable water consumption in the shower relate to different dimensions of perceived well-being? Empirical evidence from university students

ABSTRACT
 Water scarcity is already a worrying issue and it is predicted to get worse in the future. This creates an imperative to use water efficiently and sustainably. In the domestic sphere, one of the main uses of water is showering, not only for hygiene reasons but also as a wellness activity. In order to gain insight into the implications of sustainable shower use, in this paper we analyse the relationship between subjective well-being and water consumption in the shower. We aim to answer the following questions: 1) How does shower water consumption relate to subjective well-being, 2) Does this relationship differ depending on showering habits (time spent in the shower, and number of showers per week), and 3) Does this relationship differ depending on the season (winter and summer). The dataset contains information on 937 students from different disciplines at the University of Granada, Spain. The different interpretations of subjective well-being considered are life satisfaction, affect, and vitality. Results suggest that there is a negative relationship between water consumption and subjective well-being, in line with the literature that identifies a well-being dividend from green behaviour (being pro-environmental helps the environment and increases happiness). All subjective well-being dimensions are negatively related to time spent in the shower, regardless of the season. In contrast, the frequency of showering is not significantly related to well-being. Therefore, it appears that higher water consumption does not translate into higher perceived well-being, indicating that there is no conflict between efficient shower water use and individual well-being.


Introduction
Global freshwater use has increased six-fold in the last 100 years, mainly due to population growth, economic development, and changing consumption patterns (United Nations 2021). In the coming decades, water demand will continue to grow, which, coupled with the effects of climate change, will result in water becoming an even scarcer resource (Burek et al. 2016).
To tackle water scarcity, it is important to promote water efficiency in all sectors. In particular, Sustainable Development Goal 6 aims to ensure that all people have access to water and sanitation (United Nations 2015). In the domestic sphere, one of the main uses of water is for personal hygiene, which accounts for around one third of indoor household water consumption (Makki et al. 2015;Matos et al. 2013;Willis et al. 2011;2013). As such, personal hygiene practices are an interesting target for water-saving policies.
Thanks to the development of technology and domestic infrastructure, along with the evolution of social norms on grooming and lifestyle changes, daily showering has become established as the most common personal hygiene practice (Hand, Shove, and Southerton 2005). At the same time, the purpose of showering has also evolved, with it becoming common to shower not only for hygienic reasons, but also as a wellness-generating activity (Quitzau and Røpke 2009). These changes often mean more frequent, longer showers, which implies higher water consumption (see, for example, Gram-Hanssen et al. 2020;Lindsay and Supski 2017;Quitzau and Røpke 2009).
Unsustainable water use associated with the hedonic aspect of showering is explained by the fact that people tend to prioritise pleasure over water and energy conservation (Quitzau and Røpke 2008). But to what extent does higher water consumption in the shower have an impact on the perception of well-being? Does sustainable use of water resources in the shower really have a cost in terms of well-being? Previous research has shown that, in general, adopting pro-environmental behaviours positively influences well-being (Zawadzki, Steg, and Bouman 2020). Furthermore, there is evidence that higher household water consumption is not associated with improved wellbeing (Chenoweth et al. 2016). However, there are no related studies that analyse the particular case of showering.
Given the different possible applications of water, its relationship to subjective well-being is strongly determined by the specific use under consideration. Therefore, as a novelty, this study builds on previous evidence on water consumption and well-being by taking into account a specific application of this resource. In this paper, we explore the relationship between shower water consumption and subjective well-being by considering showering habits (i.e. frequency and duration) in winter and summer, and including several measures of well-being. Specifically, we use life satisfaction, positive and negative affect, and subjective vitality to cover, respectively, the cognitive, affective, and eudaimonic dimensions of subjective well-being. For the analyses, we use data from a sample of 937 students from the University of Granada (Spain).
The results of the regression analyses show that higher water consumption in the shower is significantly and negatively related to subjective well-being. Specifically, it is associated with lower life satisfaction, lower subjective vitality, and higher negative affect. On further analysis of the relationship, we find that frequency of showering is not associated with subjective well-being. However, longer duration is negatively related to all dimensions of well-being. The results remain the same regardless of the season considered. Adapting daily habits to mitigate environmental problems is an essential part of the transition to a sustainable society. It is particularly important to adopt sustainable showering habits, given how water-and energy-intensive this activity is. The research results are therefore promising, as they suggest that efficient showering is not detrimental to individual subjective well-being, which in turn will facilitate the implementation of public policies aimed at water conservation.
The rest of the article is structured as follows: Section 2 reviews previous literature that provides some insight into the relationship between shower water consumption and subjective well-being, providing arguments that support both directions of this relationship. Section 3 describes the method and materials. Section 4 presents the results of the analyses. Section 5 discusses the results. Section 6 outlines the limitations of this research and identifies some opportunities for future research. Finally, section 7 highlights the conclusions of the research.

Literature review
Water is closely linked to well-being. As well as being essential to physical health, it also plays a key role in subjective well-being. A number of studies have found that better access to fresh water is associated with greater life satisfaction (Guardiola, González-Gómez, and Grajales 2013; García-Rubio, and Guidi-Gutiérrez 2014; Nadeem, Cheo, and Shaoan 2018; Nadeem et al. 2020). In fact, in some contexts, the influence of satisfaction with water on subjective well-being may be more important than satisfaction with other domains of life, such as money or leisure (Guardiola, González-Gómez, and Grajales 2013). In this regard, it has also been found that the introduction of piped water leads to an increase in people's happiness (Devoto et al. 2012;Mahasuweerachai and Pangjai 2018).
While water is a key factor in subjective well-being, once basic needs are met, higher water consumption does not necessarily contribute to greater well-being. DeLeire and Kalil (2010) analysed the relationship between different components of consumption expenditure and life satisfaction using an American sample, and found that consumption of utilities and housing -which includes water consumption -is not related to this dimension of subjective well-being. For a British sample, Chenoweth et al. (2016) found that in general there is no association between well-being and water consumption, although they reported negative correlations between water use and some individual well-being parameters. Similar conclusions have been drawn from research exploring the relationship between water-saving behaviour and subjective well-being. In this vein, Kaida and Kaida (2016) found that domestic water-and energy-saving behaviours were positively correlated with life satisfaction in a Swedish sample. These findings are in line with those of Suárez-Varela, Guardiola, and González-Gómez (2016), who found in a Spanish sample that actions aimed at saving water in the household are positively or non-significantly related to life satisfaction. Likewise, the study by Buhl, Liedtke, and Bienge (2017) using a German sample shows a negative relationship between natural resource consumption and life satisfaction.
Although the above findings decouple higher consumption from higher well-being, none of this evidence specifically addresses the relationship between shower water consumption and subjective well-being. Despite the fact that several studies have found a positive relationship between the adoption of pro-environmental behaviours and well-being (e.g. Ambrey and Daniels 2017; Guillen-Royo 2019; Kaida and Kaida 2016;Schmitt et al. 2018;Xiao and Li 2011;Zannakis, Molander, and Johansson 2019), some research has identified exceptions, indicating that the association between the two concepts depends on the type of behaviour considered. For example, Verhofstadt et al. (2016) showed that some activities (e.g. consuming fresh and seasonal products) reduce individuals' ecological footprint while increasing their well-being, while other actions that shrink the ecological footprint (e.g. limiting meat and fish consumption or living in a small house) are detrimental to subjective well-being. Similarly, Lenzen and Cummins (2013) found that some actions are beneficial for well-being and the environment (e.g. living with other people), whereas others entail trade-offs between well-being and environmental impact (e.g. using the car).
In the case of water consumption in the shower, some studies suggest that higher consumption may be associated with greater well-being. However, scientific evidence in this regard is scarce and limited to qualitative research. For example, Quitzau and Røpke (2009) analysed the transformations in the use and meaning of Danish bathrooms over the last decades, finding that the concept of showering has evolved from merely washing to an activity that also provides pleasure and wellbeing, which in many cases has led to a change in showering habits. Based on their qualitative interviews in Danish households, Gram-Hanssen et al. (2020) reported that some people prolong shower time as a form of relaxation, accompanying it with music or the use of certain products. In response to the stresses of modern life, showering becomes an activity that offers peace and quiet, an opportunity to take time for oneself and enjoy a moment of privacy (Quitzau and Røpke 2008). Lindsay and Supski (2017) used focus groups to study the water consumption practices of people in different Australian cities, highlighting the therapeutic value of showering and its use as a tool for managing stress and emotions. Other benefits of showering that have been reported in the scientific literature include its potential to improve sleep (Whitworth-Turner et al. 2017) and even the possibility of using it as a treatment for depression (Shevchuk 2008).
In sum, what has been presented in this section underlines the complexity of the relationship between water consumption and subjective well-being. Water is a resource with different functions, and can be considered a basic necessity or a luxury good, depending on the case. Therefore, in order to study the relationship between water consumption and subjective well-being, it is necessary to distinguish between the different uses. In this study, we focus specifically on the shower, as it is where most water is typically consumed in households (Makki et al. 2015;Willis et al. 2011;2013). Thus, we provide the first quantitative evidence on shower water consumption and subjective well-being.

Data
This research is based on information from a survey of 1150 students at the University of Granada, Spain, who habitually had showers instead of baths. The city of Granada is located in southern Spain, a semi-arid area suffering from recurrent droughts and facing extremely high-water stress (World Resources Institute 2019). As for the study population, it is mainly composed of young people. Pérez-Urdiales, García-Valiñas, and Martínez-Espiñeira (2016) identified different residential water consumption profiles in Granada and age was a significant factor in defining these profiles. In particular, young adult households characterised the group with the lowest water consumption. Although young people may use water more efficiently in general, evidence suggests that their showering practices tend to be less sustainable (Stanes, Klocker, and Gibson 2015).
The fieldwork was carried out in March and April 2019. A research team visited classrooms in different faculties to conduct the questionnaire. Specifically, students from the disciplines of economics, political science, sociology, social work, pedagogy, medicine, environmental sciences, and computer science were surveyed. To ensure the consistency of the questionnaire, a pre-test was carried out with 95 participants. The students accessed the questionnaire online via the Qualtrics platform 1 and did not receive any payment for their participation. Prior to the start of the survey, respondents were informed that confidentiality and anonymity would be protected. In addition, participants were made aware of their right to withdraw.
Before running the analyses, observations with missing or nonsense values for the variables of interest were removed. Observations with extreme values (5 participants who reported taking showers lasting between 45 and 60 min) were also removed to avoid distorting the results. Thus, the final sample consists of 937 observations. The sample size is therefore sufficient for statistical inference analyses. Furthermore, the composition of the sample is similar to the entire student body of the University of Granada, made up mainly of people aged between 19 and 25, with a greater presence of women (University of Granada 2019). The composition of the sample can be seen in more detail in Table 1, which contains the descriptive statistics of the variables.

Measures
The following sub-sections provide a detailed explanation of the variables used in the study, divided into three groups: subjective well-being variables, shower use variables, and control variables. A summary table with a description of the variables and their units of measurement is provided in the supplementary material (Table S1). The questions and items used in the survey are also provided ( Supplementary Information 1).

Subjective well-being
We use several indicators to assess subjective well-being in order to take into account different dimensions of the experience of being well. Specifically, we incorporate measures of life satisfaction (cognitive), positive and negative feelings (affective) and subjective vitality (eudaimonic).
The measure of life satisfaction is related to the judgements and evaluations a person makes about his or her life in general (Dolan, Peasgood, and White 2008). Participants answered the question "How satisfied are you at this moment with your life as a whole?" on a scale from 0 (very dissatisfied) to 10 (very satisfied). The use of this 11-point scale is very convenient because, as del Saz-Salazar et al. (2019) point out, Spanish people are used to it since childhood as a rating system.
Respondents' affective state was assessed using the Positive and Negative Affect Schedule (PANAS, Watson, Clark, and Tellegen 1988), which consists of two separate 10-item scales, one for positive affect and one for negative affect. The former includes feelings of achievement, enthusiasm and commitment (e.g. motivation, alertness, determination, pride), while the latter includes feelings of distress and discomfort (e.g. irritability, shame, guilt, insecurity). Participants indicated the degree to which they had experienced these feelings in the past 7 days using a 5-point Likert scale (from 1, "very slightly or not at all" to 5, "extremely"). Positive affect and Negative affect variables were calculated as the sum of their respective item scores.
Subjective vitality, understood as the feeling of energy and aliveness derived from full physical and psychological functioning, was measured using the Subjective Vitality Scale (Ryan and Frederick 1997). Respondents rated 6 items related to feeling full of life (e.g. "I feel alive and vital", "I get excited every new day") on a 5-point Likert scale (from 1, "totally false" to 5, "totally true"). We calculated the variable Vitality as the sum of these scores.

Shower use
We captured shower habits through four questions. First, respondents had to answer two questions about how many times they shower per week, one referring to the summer and one to the winter months (variables Number Summer and Number Winter). Secondly, participants were asked about how long they stay under the water each time they shower, again with separate answers for each season (Time Summer and Time Winter). We made this distinction between seasons because previous research has shown that weather is a determinant of shower water use (Rathnayaka et al. 2015).
From the shower frequency and duration variables, we calculated the time spent in the shower per week and created two variables that reflect the weekly shower water consumption in hectolitres for summer and winter (Consumption Summer and Consumption Winter). To approximate consumption, we multiplied the weekly time spent in the shower by 14, which is the average number of litres per minute consumed in the shower in the region (Watson 2017). Note that although the consumption indicator we used is not very precise, multiplying by a scalar does not affect the relationships we aim to study.

Control variables
We also used a set of sociodemographic variables to control for their effect on subjective well-being in order to avoid spurious regressions. We asked about the parents' monthly income, proposing eight intervals as possible answers (the lowest category being less than €499 and the highest €5000 or more). We estimated income as the midpoint of the selected range, except for the highest category, which we estimated at €6000. We calculated per capita income by dividing by the number of inhabitants in the household and took the natural logarithm of this amount to account for the diminishing marginal effect of income on subjective well-being (Easterlin 1974;Diener et al. 1993). Also, we included in the analyses the respondents' age and age squared, given the U-shaped relationship between age and subjective well-being reported by previous studies (Dolan, Peasgood, and White 2008). To capture participants' social relationships, we asked how often they are in contact with their family, friends and neighbours. Respondents indicated the frequency for each group using a 5-point Likert scale (from 1, "never" to 5, "every or almost every day") and we calculated the variable Relationships as the average of the three scores given. Respondents indicated their health status by selecting one of the proposed categories (0, "major problems"; 1, "moderate problems"; 2, "mild problems"; 3 "no problems"). In addition, dummy variables were included to indicate gender (equal to 1 if female), marital status (equal to 1 if single), and employment status (equal to 1 if working as well as studying).

Method of analysis
Regression analyses were used to explore the relationship between showering practices and subjective well-being, providing information on the nature and strength of the relationship. We tested whether subjective well-being is explained by individuals' shower habits and socio-economic characteristics, using the general specification of the estimated equation, as follows: where i refers to the i-th individual in the sample (i = 1, … , 937), SWB ij represents the variables ( j = 4) we use as measure of subjective well-being (life satisfaction, positive affect, negative affect and subjective vitality), SU il corresponds to the six shower use variables (estimated consumption, shower duration, and shower frequency, in summer and winter, denoted by l), X i denotes the set of socio-economic variables, and 1 i is the error term. We used several model specifications to incorporate the different well-being dependent variables and the different shower use variables. All these model specifications were estimated using ordinary least squares (OLS). Although the ordinal nature of the life satisfaction variable makes it more appropriate to use ordered probit or ordered logit techniques for this dependent variable, we applied OLS for ease of interpretation and because there is evidence that the results yielded by both methods are very similar (Ferrer-i-Carbonell and Frijters 2004). Indeed, when repeating the analyses for life satisfaction using ordered probit regressions, we obtained identical results for all models (these results are not presented in the paper). Table 1 shows the descriptive statistics of the study variables. Of the 937 people included in this study, 62.86% were female, 64.35% reported being single and 25.19% were working as well as studying. The average age of the respondents was around 20 years old. Regarding the well-being variables, the mean score for positive affect is higher than for negative affect, the mean score for subjective vitality is closer to its maximum value than to its minimum, and life satisfaction is around a score of 7, which is slightly lower than the mean life satisfaction reported in other studies with Spanish university students (e.g. del Saz Salazar and Pérez y Pérez 2022). Shower use variables indicate that participants' showering behaviour is quite unsustainable, with the estimated shower water consumption exceeding 1100 litres per week in both seasons. The average shower duration exceeds eight minutes in summer and eleven minutes in winter, while the average number of showers per week is around seven in winter and nine in summer. It is particularly striking that certain extreme behaviours, such as 30-minute showers or showering up to 16 times a week, are not entirely uncommon among the study participants. Histograms for the well-being and shower variables can be found in the supplementary material ( Figures S1 and S2 respectively).

Results
The results of the estimations including weekly shower water consumption (Table 2), shower duration (Table 3), and the number of showers taken per week (Table 4) are presented below. The models in (a) include the shower use variables for the summer months, and the models in (b) those for the winter months. For all estimated models, the joint significance test indicates that they are globally significant. The coefficients of determination range from 8% to 15%, with the models for subjective vitality having the best fit, and those for negative affect the worst. Although these R 2 values are quite low, they are within the range of the typical values found in studies of subjective well-being and do not pose a problem for the purpose of the study (OECD 2013).
When we consider the relationship between subjective well-being and shower water consumption, we find the same results for both seasons. The more water a person consumes in the shower, the lower their life satisfaction (β = −0.0146, p < 0.1 in (a); β = −0.0215, p < 0.01 in (b)), the more negative emotions they experience (β = 0.0790, p < 0.01 in (a); β = 0.0794, p < 0.05 in (b)), and the lower their subjective vitality (β = −0.0368, p < 0.1 in (a); β = −0.0453, p < 0.05 in (b)). As can be seen from the coefficients, the relationship of water consumption is higher in absolute value for negative affect, both in summer and winter. In contrast, positive affect is not significantly related to shower water consumption.
In Table 3 we further investigate the relationship between water consumption in the shower and subjective well-being, separately analysing individuals' habits regarding duration and frequency of showers. We observe a statistically significant relationship between prolonged showers and poorer levels of well-being. Again, the results are the same in both seasons: shower duration is negatively related to life satisfaction (β = −0.0294, p < 0.01 in (a); β = −0.0343, p < 0.01 in (b)), positive affect (β = −0.0828, p < 0.1 in (a); β = −0.0813, p < 0.05 in (b)), and vitality (β = −0.0876, p < 0.01 in (a); β = −0.0770, p < 0.01 in (b)), and positively associated with negative affect (β = 0.119, p < 0.01 in (a); β = 0.135, p < 0.01 in (b)). As in the previous models, the strongest relationship is on negative affect.
Finally, as Table 4 indicates, we find no significant association between the number of showers and subjective well-being. The negative relationship between water consumption and well-being is explained only by the time spent in the shower and not by the frequency of showers.

Discussion
In this research, we explored the relationship between shower use and individual well-being using a sample of university students. Our regression results suggest that higher levels of water consumption in the shower are associated with lower subjective well-being (lower life satisfaction and subjective vitality, and higher negative affect). When we studied showering habits in more depth, we found that the duration of showering is significantly and negatively related to all dimensions of subjective well-being considered, while the frequency of showering is not a significant predictor of any of the well-being measures. These associations appear to be robust and hold for the different seasons, as we found no differences between summer and winter habits in terms of their relationship with well-being.
In line with some previous research, we found that caring for the environment and people's wellbeing are compatible goals. Positive associations between commitment to pro-environmental actions and well-being have been demonstrated for a variety of behaviours, such as purchasing behaviour (e.g. Xiao and Li 2011), environmental volunteering (e.g. Binder and Blankenberg 2016), or waste behaviour (e.g. Jacob, Jovic, and Brinkerhoff 2009). However, this is the first time that All models are statistically significant at 1%. Robust standard errors in parentheses. *** p < 0.01, ** p < 0.05, * p < 0.1 All models are statistically significant at 1%. Robust standard errors in parentheses. *** p < 0.01, ** p < 0.05, * p < 0.1. All models are statistically significant at 1%. Robust standard errors in parentheses. *** p < 0.01, ** p < 0.05, * p < 0.1. evidence has been provided for water consumption in the shower. The results reported in this study add to the evidence supporting the double dividend theory (Jackson 2005), which holds that proenvironmental behaviour is beneficial for both the environment and the person engaging in it. The findings of this study are policy-relevant and can guide the design of public awareness and education campaigns aimed at encouraging efficient water use. Informational campaigns have been found to be a widespread and effective tool for promoting the sustainable use of water resources at the household level (Katz et al. 2016). In the fight against the climate crisis, it is essential to develop environmental policies that do not adversely affect, or that even improve, citizens' welfare as such measures are likely to enjoy greater public support (Lenzen and Cummins 2013). Previous research on showering practices has identified showering as a wellness-generating activity, with long showers being defined as a form of daily therapy "necessary for a good life" (Lindsay and Supski 2017). Nevertheless, our results contradict this idea. As Kasser (2002) argued, sometimes certain aspects of personality and environmental circumstances lead people to try to meet their needs in ways that do not ultimately satisfy them. Unsustainable long showers are an example of a social trend that does not really meet the needs it is supposed to, at least for educated young people living in an area of high water stress. People are unlikely to change their showering habits if they believe that such actions are beneficial to them. Therefore, policy-makers should convey the message that increased water consumption in the shower, and especially prolonged showers, may be negatively associated with well-being. It should be emphasised that it is not a good idea to use showering as a leisure and relaxation activity that improves well-being; rather, there are other more appropriate practices that should be adopted for these purposes, such as meditation (Dhandra 2019) or spending time with loved ones (Becchetti, Trovato, and Londono Bedoya 2011). Citizens should also be made aware of the potential gains of adopting sustainable showering practices, both for subjective well-being and for physical well-being, in terms of the associated skin health benefits.

Limitations and future research
This research provides interesting results that could help in the design of water saving campaigns. Future research could test the impact and scope of a campaign based on the findings of the study. Nevertheless, the study has a number of limitations that make it necessary to be cautious about its implications. Firstly, this study was carried out using a sample of students, mostly young people (the average age of the participants was around 20 years old). It is interesting to study this age group because young people have previously been identified as some of the highest users of water in the shower and have also been found to be less willing to reduce the duration and frequency of their showers (Lindsay and Supski 2017;Stanes, Klocker, and Gibson 2015). The results of this study could therefore help to lessen resistance to the necessary change in showering habits among a relevant segment of the population. However, we cannot generalise the results to the whole population, as individual characteristics such as age and educational level could be influencing the relationships found. Future research could extend the analyses carried out here to samples with a more varied profile to see if the findings of the present research hold.
Secondly, the fieldwork for this study was conducted in the city of Granada, southern Spain. The fact that it is in an area of high water stress makes it an interesting context for research, although it could be conditioning the results obtained. Future studies could test whether the relationship between showering habits and well-being is different in areas with other characteristics. It would also be worth studying this relationship in other countries with a different cultural context, as culture may be an influential factor in this relationship.
Thirdly, it should be noted that the data used in this study are cross-sectional, which limits the ability to make causal interpretations. For this reason, the results of the regression analyses have been interpreted as correlations. The negative relationship between water consumption in the shower and subjective well-being could plausibly be a case of reverse causality. In other words, it could be that people with lower well-being make less sustainable use of the shower; for example, unhappy people might spend more time in the shower as a form of escape, using the shower as a refuge. In any case, regardless of the direction of causality, the results of the study seem to disprove the idea that higher water consumption in the shower is associated with higher well-being, implying that using the shower in a sustainable way is compatible with achieving a high quality of life.

Conclusion
Moving towards an environmentally sound future requires us to change our daily practices. Showering is a water-and energy-intensive activity and is one of the main uses of water in the household, making sustainable shower use particularly important. In this paper, we examined the relationship between efficient shower water use and subjective well-being. To our knowledge, this is the first study to empirically link shower habits and well-being. Using regression analyses with a sample of university students, we found that shower water consumption is negatively associated with life satisfaction and subjective vitality, and positively associated with experiencing negative emotions. Decomposing water consumption into shower duration and frequency habits, we found that the negative relationship between consumption and well-being seems to be explained by the time spent in the shower. Shower duration is associated with worse levels of all the indicators of wellbeing used (life satisfaction, positive and negative affect, and subjective vitality). In contrast, the frequency of showering is not significantly related to any dimension of well-being. Although showering habits are different in summer and winter, both in terms of frequency and duration, there are no differences in their relationship with subjective well-being, with the same results being obtained for both seasons. The results run counter to the growing tendency to view showering (especially long showers) as a wellness activity, since higher water consumption does not translate into higher perceived well-being.The absence of conflict between efficient water use in the shower and well-being could facilitate the implementation of public policies aimed at reducing water consumption in the shower. Note 1. In the design of the questionnaire, the survey was tested to work on all types of electronic devices, following del Saz-Salazar, Gil-Pareja, and García-Grande (2022) and Liebe et al. (2015). When any student did not have an electronic device to fill out the survey, the researcher provided one.