Children’s socialization into the mobile preschool: a priming event collectively performed by novice children, ‘old-timers’, and pedagogues

ABSTRACT Using video-ethnographic data from a ‘try-on day’ in a bus-based mobile preschool, we discuss how children with different levels of experience collaborate with one another and with pedagogues to socialize newcomers into an ongoing community. Analyses show how pedagogues create moments of collective orientation and, besides through verbal instructions, invite newcomers to participate in core activities with older children. The novices engage in the priming event by intent participation, while the older children assume, and are assigned, the role of more experienced participants – ‘old-timers’. In this collective socialization, old-timers, children, and pedagogues strive to create a smooth transition for novices, particularly by stressing the specificity of participating in a preschool that is mobile and located in a bus. The results illustrate how becoming a mobile preschool child entails understanding and mastering competences such as safely riding the bus, eating meals in the bus, and walking in line in diverse spaces.


Introduction
'On the bus you can eat the whole fruit, except for the little stem', said five-year-old Eve when introducing newcomers to eating pears in the mobile preschool. She, who had participated for a year in the preschool as one of the youngest, was transformed into an 'oldtimer' when a group of novice children came for a visit in a priming event. Corsaro and Molinari (2000) introduced the notion of priming events that 'involve activities in which children, by their very participation, attend prospectively to ongoing or anticipated changes in their lives ' (17). Priming events are crucial for children's understanding of temporality and transitions in life and can be more or less formalized. In (pre-)school, formal priming events are project oriented and often scheduled at the end of the spring semester's student visits to their future schools, for example, when Eve, as an experienced participant, met the upcoming group of children and introduced them to the ritual of eating fruit in the mobile preschool practiceas she said, 'on the bus'. Corsaro and Molinari (2000; considered the transition to primary school, and although research into educational transitions has mainly considered transitions to primary school (e.g. Fane et al. 2016;Ballam, Perry, and Garpelin 2017), the significance of early childhood education and care (ECEC) and children's perspectives has recently been underlined in such transitions (Einarsdottir 2011;Kocyigiti 2014;Ackesjö 2016). Recently, more studies have examined transitions to ECEC (Kalkman and Clark 2017;Wilder and Lillvist 2018;Picchio and Mayer 2019). However, little attention has been paid to transitions within ECEC (Balduzzi et al. 2019), although, for example, contemporary Swedish preschool practices with agegroup divisions mean that young children undergo one or more transitions during their time within ECEC (Garpelin and Kallberg 2008). The implementation of 'preschool class' in Sweden, a year between ECEC and the start of primary school existing since 1998 and mandatory since 2018, entails yet another transition (Karlsson et al. 2006;Ackesjö 2016;Sandberg et al. 2017).
A review of educational transitions in early childhood and schooling in Europe (Balduzzi et al. 2019) shows that, due to the organization of early education, children often undergo several transitions even before the more well-known and researched transition from ECEC to primary school. It is therefore essential to look more deeply into children's transitions and socialization during ECEC. This especially applies to children starting their education in mobile preschool practice for whom these changes involve more than just moving from one division to another in the same building, encountering new pedagogues and material, as is usual when preschool children move up to the next age group; rather, these new 'mobile preschool children' move to a division with a very specific time-spatial organization and on a daily basis travel by bus to various locations, encountering diverse environments, materials, and people (Gustafson and van der Burgt 2015;Ekman Ladru and Gustafson 2018). Wilder and Lillvist (2018) emphasized the need for collaboration between parents, teachers, and ECEC workers in order to understand children's learning trajectories and to create transitions including both continuity and change for the child (see Docket and Einarsdottir 2017 for discussion of the need to recognize discontinuity as an important dimension of children's learning and development). To our knowledge, there is little research into how children with different levels of experience collaborate with one another and with pedagogues to introduce novice children to ongoing practices (Lave and Wenger 1991;Corsaro and Molinari 2000).
Using ethnographic data from a formal priming event, a 'try-on day' when children about to start mobile preschool visited for a day in May, we discuss how novice and experienced children and pedagogues contribute to the socialization process in various ways. Using detailed video observations of the whole day-long priming event, we see how experienced children shared their knowledge of how to participate, using verbal information and embodied knowledge of daily routines and activities in diverse spaces. Introducing newcomers to mobile preschool practice also meant inviting them to participate in busspecific rituals and negotiation of rules. Novice children were engaged in observing, listening to, and following older children's examples and pedagogues' instructions. Pedagogues used both collective and individual instructions, but often just invited the newcomers to learn by participating. Simultaneously, what pedagogues and children consider important in the priming event illustrates what is considered specific to the mobile preschool practice and what the novices need to learn, for example, about safety and daily routines such as eating meals in the bus, walking in line, and staying with the group in diverse spaces.

Theoretical framework
With a theoretical view of children as active participants in priming for educational transitions (Corsaro and Molinari 2000) and of learning as a process whereby novice children, by participating with older, more experienced children and adults, become part of a community of practice (Lave and Wenger 1991), we discuss how socialization into the mobile preschool is collectively performed by novices, old-timers, and pedagogues.
The mobile preschool is an ECEC institution that both resembles and differs from other such institutions and schools. One similarity is the teacher-child relationship, in which teachers are responsible for teaching children specific subjects stipulated in the curriculum, such as language, mathematics, and democratic values, even though the Swedish ECEC curriculum (Curriculum for the Preschool 2018) emphasizes both formal teaching and informal learning through play. Another similarity is that children are socialized into being (pre)school children (Karlsson et al. 2006;Kalkman and Clark 2017). However, the mobile preschool, due to its mobile character, use of a bus, and diverse public spaces, is also a practice in which participants must learn many skills not taught in ordinary schools. Such skills and knowledge are difficult to teach in traditional instructional ways, but rather require that the children learn through participation in the mobile preschool and diverse spaces (Ekman Ladru and Gustafson 2018). This is aligned with how Lave and Wenger (1991) saw learning during informal apprenticeship as a process of moving from peripheral to central participation in novel practices.
In this light, the mobile preschool is regarded as a community of practice in which, in addition to following formal instructions, the novice children learn by intent participation (Rogoff et al. 2007;Rindstedt and Aronsson 2012), actively observing the ongoing activities of adults and older, more experienced children. This is aligned with Corsaro and Molinari's (2000) theorization regarding children's collective participation in educational transitions as priming events, in which children by their very participation attend prospectively to ongoing or upcoming changes. Corsaro and Molinari discussed formal priming events (e.g. school trips) as well as informal priming (in play and peer culture), emphasizing that priming implies that children separate themselves from their earlier context, gradually participating in the novel practice. Here, we focus on how the participants (i.e. novices, old-timers, and pedagogues) are collectively engaged in socializing new mobile preschool children during a priming event for the mobile preschool practice. This entails collective orientation to certain 'core' activities in talk and action as well as collective involvement in negotiating how to behave during and handle these activities (Corsaro and Molinari 2000). In line with Lave and Wenger's (1991) discussion of changing forms of participation from 'entrance as a newcomer, through becoming an old-timer with respect to new newcomers' (56), this process, in addition to priming the new children, also changes the participation of the older children, recasting them as old-timers.

Research context and method
The empirical data derive from long-term video-ethnographic research in a mobile preschool practice, the 'Pippi bus'. The fieldwork was conducted over 14 months, and consisted of 44 days and 150 h of video-recorded observations. Ethnographic research always builds on formal as well as informal access and on mutually developed trust between researchers and participants, which requires special attention when conducting research with young children. Besides formal consent from parents and the involved professionals, we also continuously informed the children and requested consent from them, as well as paying attention to the children's diverse ways of showingverbally or through body languagewhether and how they wanted to participate. This is especially important in educational settings where children are generally used to following adults' rules. The Regional Ethics Review Board approved the project, and for reasons of confidentiality, the names and details of the places, children, and teachers have been anonymized in the text and photographs.
Here, we focus on one specific day in May, when twelve 4-5-year-old children entering the mobile preschool division in the autumn were participating in a priming event called the 'try-on day'. Children are usually part of the mobile preschool for two years, and every autumn part of the group is new. On the observed day, 19 children were participating: 12 novice children and 5 who had already been on the bus for almost a year and were to continue the next year. On this day, the latter five were transformed from having been the youngest to being 'old-timers'experienced mobile preschool children. These 'new old-timers' were taking over this role from older children who had been in the mobile preschool for two years: those older ones were to start preschool class after the summer and were not participating in this try-on day.
Mobile preschool is an ECEC practice conducted on a bus and part of the ECEC system in Sweden based on an 'educare' model offering both daycare and education to children 1-5 years old when their parents are working or studying. All Swedish ECEC is called 'preschool' (Swedish: förskola) and has a curriculum of its own (Curriculum for the Preschool 2018). Mobile preschools are primarily a Scandinavian phenomenon, and in 14 municipalities around Sweden there are currently about 40 preschool buses that on a daily basis travel to various locations where everyday preschool activities and routines are performed (Gustafson, van der Burgt, and Joelsson 2017). Offering children 'new learning environments' in order to further develop mainstream preschool pedagogy is one rationale for mobile preschools, often in combination with municipalities' challenges addressing the lack of space for preschool children. The mobile preschools are mostly organized along the lines of the Pippi bus examined here, as one division of a stationary preschool. The bus accommodates 20 children and three teachers, two of whom also work as bus drivers. The children participate in the mobile preschool Monday to Friday from 9 am to 3 pm and, depending on their parents' working schedules, attend the stationary preschool before and after bus hours. The bus had been remodelled and equipped with a toilet, a kitchenette, and seats arranged in groups of four around small tables. The preschool travels to various locations where the children and teachers participate in diverse educational activities and play.
During the try-on day, two researchers (i.e. the authors) made video recordings, conducted participant observations, and took field notes in order to analyse the transition and socialization of novice children into the mobile preschool practice.

Findings
The purpose of the event is for the children who will constitute the group in August to meet as well as to prime the newcomers for what will be expected of them when they enrol in the mobile preschool in August. The pedagogues are experienced and have conducted this try-on day several times before; they run the day to get to know the novice children and introduce them to the mobile preschool practice. In this process, they encourage the children already enrolled in the mobile preschool to take on the role of experienced mobile preschool children. The children themselves are eager to display their experience and knowledge to the novices, and the change in the participation of the 'new old-timers' becomes obvious (Lave and Wenger 1991;Corsaro and Molinari 2000).
When the try-on day started, the novice children were in one sense already participants in the mobile preschool but from a literally peripheral position, as newcomers entering into a novel practice (Lave and Wenger 1991). During our long-term fieldwork, we saw the novice children standing by the stationary preschool gate every morning, observing the mobile preschool bus leave and then return in the afternoon with the older 'bus children'. Some of them had older siblings who had been bus children. On the observed morning, it was the novices' turn to experience riding on the bus, instead of looking at it, and to participate for one day in the mobile preschool practice to become primed (Corsaro and Molinari 2000) for what was expected of them after the summer.

Mobile preschool-specific knowledge
Taking a preschool group out of the preschool premises to travel by bus entails various safety arrangements. Participation in the mobile preschool therefore involves learning to comply with safety rules. This is knowledge that experienced mobile preschool children have already embodied (Ekman Ladru and Gustafson 2018; Ekman Ladru and Gustafson 2020). Learning to safely move in and between diverse spaces to participate in daily routines, educational activities, and play is a major socialization task in becoming a mobile preschool child (Gustafson and van der Burgt 2015; Ekman Ladru and Gustafson 2018; Ekman Ladru and Gustafson 2020). Therefore, during the day, safety was made a central theme by the pedagogues, featured as something the novice children had to learn from the very beginning. For instance, when the children first entered the bus in the morning, the pedagogues talked about safety rules and stressed that 'on the bus there will be specific rules', adding that 'there can be different rules in different places since every place is a bit different'. When entering into this new practice (Lave and Wenger 1991), the novice children must learn to participate in the time-spatial organization of the preschool day without specially designed playrooms, dining halls, playgrounds, etc. As shown below, this was highlighted during the try-on day when activities and routines such as (i) safely riding the bus, (ii) eating meals on the bus, (iii) walking in line, and (iv) exploring diverse spaces while staying with the group were highlighted as important competences to learn. Both pedagogues and children were oriented to these activities in talk and action and were collectively involved in negotiating how to behave and handle them (Corsaro and Molinari 2000). The try-on day as a priming event brought these mobile preschool conditions to a head when the pedagogues wanted to show what was essential to know, making this event a useful example of key themes in the children's transition to the mobile preschool.
During the try-on day, the orientation of the novice children was explicitly made into a shared responsibility between the pedagogues and the older, more experienced children. The pedagogues emphasized this by repeatedly asking the 'new old-timers' to 'help the new children understand how it is on the bus', in line with how Lave and Wenger (1991) described more experienced participants introducing newcomers. However, it also became obvious that the novices were not passive receivers of help and knowledge but also actively participated in this process by observing, listening, asking questions, and applying knowledge from other social arenas (Rogoff et al. 2007;Rindstedt and Aronsson 2012). During the try-on day, children and pedagogues used various strategiesboth planned and improvisedto prime the novices for the mobile preschool practice. Below, we further consider how this was done when novice children were learning to safely ride the bus, eat on the bus, walk in line, participate in diverse spaces, and stay with the group.

Safely ride the bus
Riding the bus safely was a recurrent routine, and the pedagogues stressed that the novice children must learn this routine in order to participate in the mobile preschool practice. However, as emphasized by Corsaro and Molinari (2000), priming starts before the formal event and, as seen below, the novice children already displayed knowledge of the need for safety when actively participating in safety routines with pedagogues and other children. Safety routines are deeply embedded in the mobile preschool practice, as the more experienced children knew well and, in line with Lave and Wenger (1991), shared with the newcomers.
Pedagogues created moments of collective orientation through ritualizing safety routines such as:( i) checking each child's safety belt in a face-to-face interaction between pedagogue and child several times every day; and (ii) announcing that the children could remove their safety belts, accompanied by naming the place where they had arrived and welcoming the children to it. The safety belt rituals encompassed important social and spatial dimensions that the pedagogues wanted to incorporate into the everyday mobile preschool practice; simultaneously, these institutionalized rituals helped the children never to forget their safety work (Ekman Ladru and Gustafson 2020). One way of creating ritualized moments of collective orientation seen as essential activities by the pedagogues was to make sure that every child paid attention to safety belt use. In the mornings, this was performed as a greeting routine. When everyone had boarded the bus, one pedagogue (Sue) walked up and down the aisle, welcoming each child while ensuring that their safety belts were put on correctly. For the novice children, this was an opportunity to display their knowledge of safety rules and routines. Anne, one of the novices, observed and commented on this by saying 'you are not allowed to unbuckle the belt', displaying her knowledge of the need to keep the belt on during the journey. This was an opportunity for the pedagogue to create a moment of collective orientation, performed by Sue through responding loudly so that everyone could hear, stressing the importance of wearing the safety belts by referring to safe travelling in a car. All the children seemed familiar with this and started to discuss how safety belts worked in their family cars. While doing this, the newcomer and old-timer children and the pedagogues collectively addressed the importance of safety belts while simultaneously connecting different social arenas in the children's lives. Family and the mobile preschool practices are interconnected spaces (Christensen and O'Brien 2003) with similar routines, for example, when it comes to safe travelling. Both the pedagogues and the children were able to use knowledge gained from experience in family cars and transfer this to learning how to participate in the mobile preschool. Anne's comment shows that participating in a try-on day was not a priming event in which one starts as a tabula rasa knowing nothing about safety rules. On the contrary, children already had knowledge of how to engage in safety practices in the mobile preschool. The children had come prepared for the transition, bringing diverse knowledge and showing that informal priming had already started before entering the bus in this formal priming event (Corsaro and Molinari 2000).
Announcing that the children could remove their safety belts was the other ritualized routine that created moments of collective orientation. When the bus parked at the destination of the day, the pedagogue who was also the bus driver announced, 'Welcome to Fjällnora. You may now unfasten your safety belts'. The driver made a similar routine announcement in the afternoon when returning to the stationary preschool. Never removing their safety belts before this moment was something the children had to learn. Additionally, the pedagogues also made a routine of checking the safety belts before departure. The children's participation in this safety work was illustrated when Tom, an oldtimer, shared his knowledge of this work with the novice children when it was time to return home. 'Now they will check our belts, yes they will check our belts', Tom said just before the pedagogue started the safety belt procedure. Not only did he position himself as an experienced mobile preschool child knowing the routines and the pedagogues' mobility patterns, but he also participated in creating this moment of collective orientation and hence in priming his new peers.

Meals in the bus
Another competence that newcomers had to learn was how to participate in the mobile preschool meals. The pedagogues framed 'eating on the bus' as something that would take some practice before being fully mastered (Lave and Wenger 1991). Meals on the bus are organized differently from those in other Swedish preschools, where children and adults usually sit around tables and eat together. From our fieldwork, we learned that children and pedagogues in the mobile preschool create space for meals without ordinary dining rooms or tables when eating outdoors or, more frequently, in the bus. In the bus, pedagogues walk up and down the aisle like flight attendants, while the children sit in their seats waiting to be served (Gustafson and van der Burgt 2015; Gustafson and Melander 2018). Along with formal instructions from the pedagogues, the mealtimes, like other everyday routine activities, are filled with peer socialization in which the children learn from one another (Bevemyr and Björk-Willén 2016;Corsaro 2018). During this try-on day, how to eat on the bus was an issue raised by a pedagogue when the children first embarked in the morning. Creating a moment of collective orientation, the pedagogue first instructed the whole group of children when introducing the new meal routines in the mobile preschool, before inviting the children to participate in the conversation. During this conversation, the children were actively engaged through both verbal and (playful) body language, as when one novice child pointed at the little table in front of her and asked how there would be room for food there. Eve, an old-timer, started showing with body language how she ate while seated, and several of the newcomers smiled, imitating her body language and pretending to eat. Hence, the old-timers displayed and shared their knowledge and the novices were active in observing, imitating, and asking questions (Lave and Wenger 1991;Rindstedt and Aronsson 2012). Thereby, the novice children learned playfully from an older and more experienced child about meals in their new practice (Rogoff et al. 2007;Corsaro 2018). The pedagogue ended the discussion by describing meals as 'a bit tricky' and something they would have to practice, emphasizing that it would take some time to learn (Lave and Wenger 1991).
However, our results indicate that moments of collective orientation created by pedagogues are not bounded events that cease when the pedagogues stop speaking. Our analysis shows that the child participants continued to highlight issues raised by the pedagogues, embellishing for the newcomers the 'essential' mobile preschool routines (Corsaro 2018), and in this way furthered the introduction of novice children. For example, several minutes after the pedagogue-children conversation, when the fruit was served, Eve continued talking on the theme that meals need practice. She turned to the newcomers next to her to tell them how to eat fruit, saying, 'on the bus you are allowed to eat the whole fruit except the stem'. She showed the novice children how to eat by putting her stem on the table in front of her. The children observed Eve and followed her example, putting their stems next to hers without saying anything. By doing this, Eve and the novices together made the familiar activity of eating fruit, something all preschool children do every morning, into a special mobile preschool ritual. Eve, as a 'new old-timer', showed that the transition to the mobile preschool meant coming to a preschool with different conditions and routines (Ballam, Perry, and Garpelin 2017) (Figure 1(a,b)).

Walking in line
Additionally, the bus journeys involve recurrent spatial transitions: getting on and off the bus, walking to the location of the morning activities, returning to the bus for lunch, walking to the location of the afternoon activities, and returning to the bus again. The novice mobile preschool children must learn these daily mobility practices, often conducted by walking in line with one pedagogue in front and another at the end to maintain control of the group (Gustafson and van der Burgt 2015;Ekman Ladru and Gustafson 2018;Ekman Ladru and Gustafson 2020). The pedagogues used diverse strategies in cooperation with the more experienced old-timers (Lave and Wenger 1991) to show the novice children how to perform walking in line. However, the newcomers already displayed some familiarity with walking in line and participated in various ways, such as staying near peers or adults, listening to older children's instructions, and following their examples (Corsaro and Molinari 2000;Rogoff et al. 2007). The last was sometimes a challenge for the pedagogues, as they wanted the older children to introduce the newcomers to the routines correctly and safely, rather than teaching them secondary adjustments (Corsaro 2018).
One strategy used by the pedagogues in the collective orientation was to highlight good examples and use them in further instructions. For example, when it was time to walk in line for the first time, Maria (a pedagogue) blew her whistle and all the children immediately came running and lined up in readiness to walk (Figure 2).
They all seemed to know how to respond to the signal, and Maria praised them for immediately knowing what to do. Nora, a novice child, said, 'Tom [i.e. an old-timer] told that to us'. The pedagogue responded: 'It was really good that Tom told you a little about this', adding loudly so that everyone could hear, 'You did exactly the right thing now!' Maria thereby underlined what was considered good behaviour in the walking-inline routine. She also pointed out the benefits for the novice children of viewing the experienced children as role models. This illustrates intent community participation, in which newcomers are guided by more experienced old-timers (Rogoff et al. 2007).
Having created a moment of collective orientation when the group of children turned their attention towards Maria, she took the opportunity to explain the rules of the whistle. Pedagogues and children, both novices and old-timers, than co-operated in establishing the rule of listening to the pedagogue and the whistle. Maria informed the children that the whistle was used for two reasons: as a signal to line up to prepare to walk in line, or to gather all of them together. The children keenly observed and listened to Maria, who continued by instructing the children: 'Now, when you walk in line, you must think of not pushing one another, neither the one in front of you nor the one behind. And I will tell you when you don't need to walk in line any more'. When walking in line, the children were not only walking and making sure to follow instructions, but were simultaneously talking, singing, jumping, lagging behind, and then running to catch up, etc. (Ekman Ladru and Gustafson 2018; Ekman Ladru and Gustafson 2020). When it was time to walk from the forest back to the bus, Maria blew the whistle and the children quickly formed a line behind her and started to walk in line.
We also saw how pedagogues handled 'bad' examples and turned them into learning experiences. For instance, Leo, an old-timer, instead of joining the line, started circling around a bit behind. Margareth, who was walking at the end with two newcomers, Emelie and Nora, called Leo several times, and he followed them but at an increasing distance from the end of the line. Margareth walked on slowly, keeping an eye on Leo while talking to the girls at her side and stressing that Leo, as 'an old bus child', should know better. Nora: I did not hear the whistle. I just ran … because I saw the others there.
Nora herself described how she, a novice child, knew what to do by observing the other children (Rogoff et al. 2007). Margareth praised the two newcomers for not following Leo's example, emphasizing that he should know better as an old-timer. Margareth had to handle Leo's not behaving as a desirable role model, but she knew that he often wanted to lag behind to have the opportunity to run and catch up. Margareth trusted Leo to keep in contact with the walking group, and soon he came running. As an experienced participant in the mobile preschool, Leo, while engaged in secondary adjustments (Corsaro 2018), showed that he was well aware of how to negotiate the rules and how far behind he could remain before getting a sharp reprimand.
When walking in line later that day, Leo and other old-timers proposed running downhill the final distance back to the bus. The pedagogues approved, rearranging the line to allow some to run and others to walk. By doing this, the pedagogues showed the novices that they were willing to listen to the children's suggestions. Simultaneously, the old-timers and pedagogues together also showed the newcomers how to negotiate rules in the mobile preschool practice where running in the context of walking in line is not unusual, but must be agreed on.
The mobile preschool routine of walking in line has been discussed elsewhere as a space for children's learning as well as for receiving teacher attention and social support (Ekman Ladru and Gustafson 2018). Our results illustrate how, during this try-on day, the novice children learned how walking in line involved the possibility of receiving emotional support and one-on-one contact with a pedagogue. While walking, it was possible for newcomers to stay close to the pedagogues whom they trusted would facilitate their entry into the new community (Lave and Wenger 1991). For instance, Emma and Emelie (two novice children) approached Margareth the pedagogue at the end of the line, looking somewhat troubled and staying near her. The novice girls walked beside her, holding her hands, and Margareth supported them with physical contact and small talk. Margareth primed the girls about what to expect by telling them that after the summer they would 'become bus children every day'. Emma asked, 'Every day?'; Margareth answered, 'Yes, every day!' When they lagged behind, Margareth encouraged the girls to quicken their pace to catch up with the others who were waiting for them farther ahead. As illustrated, walking in line was not only a transport but also an opportunity to interact and prepare for what it means to become 'bus children': going every day by bus to different places, being taken care of by familiar adults, and always having to stay with the group.
Exploring diverse spaces and staying with the group Safety was a key issue when introducing the children to diverse spaces. As mentioned regarding the observed morning, every location differs and the rules depend on where one is, and the novice children were actively engaged in keenly observing and striving to understand how to participate in the different natural spaces visited during the tryon day. The ways the newcomers participated varied: while some stayed near the pedagogues and their peers, observing and asking questions, others quickly spread out over a larger area and investigated the space with peers (Corsaro 2018). The pedagogues introduced each place by giving information to the group, and then stayed near the children, chatting, giving instructions when needed, and making themselves available to help novice children successfully get to know the space (Lave and Wenger 1991). When in places with which they were familiar, the old-timers explicitly shared their knowledge and showed the newcomers how to use these places. Occasionally, the pedagogues called back the whole group for stricter instructions, especially when the children wandered too far away. Staying with the group was a major task for the children to learn.
In the morning, the group arrived at a small forest where Maria gathered all the children to review some rules and prepare them for free play. She asked the children if they knew what was important when playing in the forest, and received the desired answer from an old-timer: 'Not to run off too far'. Maria replied by saying, 'Exactly! You must always be able to see a teacher, so we can see you. Because we don't want you to get lost'. The preschool group entered the forest together and the children spread out. Several of them went a bit too far, and Maria blew her whistle and called them back. She gathered all the children again to tell them that they were too eager and had run too far away. She reminded them to stay closer to her and that they should always be able to see her. The children and pedagogues then together explored their surroundings, which were unfamiliar to the children. While some children, both newcomers and oldtimers, ran and moved in groups over a large area, others stayed near the pedagogues. The pedagogues interacted with the children near them while monitoring the others, blowing the whistle when needed and gathering the children to remind them of the rules and provide information. The newcomers were trying to understand what activities were allowed, how far they could go, and the schedule for the day, and asked about when it was time to return to the bus, when and where they were going to have lunch, etc.
The afternoon was spent in another place, a 'forest playground' built by former mobile preschool children and pedagogues out of logs, trees, and rope. This place was well known to the old-timers, who introduced the novices to the place and its play opportunities. First, however, a pedagogue introduced the playground rules, stressing that some were the same as in the preschool yard while others differed. The rules concerned safety, such as how to ride the seesaw without traditional handles and being aware that the stones were slippery from rain. The old-timers showed the newcomers around, and the children spread out in the area and started to play. In contrast to the forest visited in the morning, this playground constructed for well-known playground activities, although built in the forest and using natural materials, was designed for children and easier for them to appropriate ( Figure 3).
However, while some of the novice children immediately began playing and moving around with their peers in a lively way, others took a more peripheral position (Lave and Wenger 1991), staying near the pedagogues and keenly observing. For example, Emelie had earlier made it clear that she did not want to play at all in the afternoon when the pedagogue Maria tried to interest her in various activities. When Maria asked, 'If you can stand near us while the others play, would that be ok?' Emelie nodded and looked satisfied. She was thus offered the reassuring presence of the pedagogue while being able to watch the ongoing activities. While watching, Emelie and other novices were simultaneously engaged in various activities, such as holding the offered hand of a pedagogue, asking questions, discussing what was happening, and staying near a newcomer or old-timer peer and a pedagogue they already knew. Staying near someone might seem passive, but when considered more closely, it does involve an active intent to participate (Rogoff et al. 2007;Rindstedt and Aronsson 2012).

Conclusions
This article extends prior work on educational transitions by empirically and critically investigating a transition within early education. Drawing on a video-ethnographic study, we discuss how pedagogues and children are collectively engaged in socializing newcomers in a priming event for a transition within ECEC. We thereby build knowledge of a phenomenon many European children experience during their early education, although little discussed in educational research, policy, and practice.
Our analysis illustrates how pedagogues created moments of collective orientation when introducing new children to the mobile preschool. In these moments, the pedagogues not only talked about what was expected of the newcomers, but also invited them to participate in core mobile preschool activities through 'learning by doing' together with more experienced children. Pedagogues and children with different levels of experience were collectively engaged in socializing newcomers into the ongoing community of the mobile preschool practice (Lave and Wenger 1991;Corsaro and Molinari 2000). These results enable us to discuss priming events in a preschool group with children from two different year cohorts, a phenomenon that entails not only introducing newcomers, but also explicit change in the participation of children who have already been part of the practice for a year. By meeting the 'new newcomers', they were transformed from having been (more or less) new children into 'new old-timers'. Hence, it is important to acknowledge that priming events not only prime novices, but also prime the more experienced children for new ways of participation.
Using video-ethnographic data let us explore in detail how pedagogues and children collaborated to create a smooth transition for the newcomers as well as to emphasize what had to be learned to become a knowledgeable mobile preschool child. The novices actively engaged in this process, showing that informal priming had already begun from a peripheral position. In their intent participation, together with strategies such as observing, asking questions, and imitating, the novices interpreted the novel situation by connecting it to experiences from other social arenas. This strategy was also used by the pedagogues: by referring to well-known activities in the children's families or the preschool yard, they explained new situations in the mobile preschool practice to the newcomers. Additionally, the pedagogues created moments of collective orientation while conducting daily routine activities. For instance, by using traditional (pre-)school tactics such as gathering the children and giving collective verbal instructions to the whole group before starting new activities or arriving at a new place. Activities that both novice children and old-timers participated in and followed through in diverse ways. However, more often than starting with instructions, the pedagogues and children started simply by collectively 'doing the mobile preschool practice'. In the activities in various spaces, the pedagogues emotionally supported the newcomers by making themselves available to guide them to participate, little by little. Some of the novice children used a similar strategy, staying near an already familiar pedagogue or peer or watching from a distance what others were doing.
The old-timers took on their new positions as role models and used various strategies to share their knowledge of following rules and handling routines. However, being an experienced mobile preschool child also required broad knowledge of how, when, and where rules and routines could be negotiated and contested. Thus, there were various ways of being an experienced participant in the mobile preschool practice, including different positions in the preschool group. The detailed analyses presented here convey knowledge of how very young children (both novice and experienced) and the pedagogues collaborated, using a broad repertoire of strategies to socialize newcomers into the mobile preschool practice, as well as knowledge of how older children's participation changed when a group of novice children entered the scene.
Although both new and experienced children were involved in making the mobile preschool practice understandable and familiar, the old-timers emphasized the specific conditions of the practice. Although the mobile preschool is an informal community of practice, it also has a specific times-spatial organization with major practical implications for daily routines and activities. For the children, being a participant in a collective that travels daily to diverse locations implies a certain identity as 'bus children', and our findings illustrate how the old-timers and pedagogues were engaged in making the unfamiliar more familiar and casting familiar activities, such as eating fruit, in a new light, recognizing the discontinuity of the educational transition to the mobile preschool practice.