(Excerpt 1)
This phase needs a lot of preparation, especially for teachers. The teacher should have high creativity in designing several outdoor activities. In response to this, well-prepared material is being considered. (P1/ individual reflection)
(Excerpt 2)
The factors that influence the activities, particularly during online schooling can be divided into two types. First, the external factors which come up from the lecturer instruction, the device provided, and the internet connection. Second, the internal factors rely on the students' motivation, anxiety, and the students' needs. Â (P3/ individual reflection)
Both P1 and P3 have similar ideas that the teacher's role is quite important. P1 believes that the teacher's creativity in designing outdoor activity is a propellant factor to determine the success of the outdoor activity. In addition, they argue that teachers should modify different ways of teaching to suit the special requirements of the second language learners and be aware of technical issues. P3 takes into account students' internal factors such as motivation, anxiety, and the students' need  as contextual factors to be considered.
Structure that supports the learning process
(Excerpt 1)
At that time, the most important things that helped me  make the poster were the device that supported the design of the poster, the eligible data to be displayed, and the matched SLA theories on my data. (P2/ Individual reflection)
(Excerpt 2)
Creativity is quite important to create a poster and also the technology usage. We need to consider the color, font, theme, target reader and values. As well as a suitable website to design an attractive poster. (P1/ Individual reflection)
(Excerpt 3)
Several requirements needed to be master in designing teaching language through posters are theory, practice (activity), and technological skill. (P3/ Individual reflection)
P2 and P3 have equal minds that technology usage is a prominent skill that poster creators must hold. It helps them to create an attractive poster as well. In addition, P1 contends choosing the right device which helps craters to create a poster. As we know that technology nowadays brings tons of positive effects for users.
DISCUSSION
SLA is an interesting theory to learn as it offers pedagogical alternatives in teaching and learning a second language. Thus, SLA is one of the compulsory courses in the initial teacher English education program in Indonesia. However, slight knowledge gained from classroom learning activity (e.g. teacher lecture, textbook reading, and interactive discussion) was not enough to enhance conceptual comprehension (James, J. K., & Williams, T.,2017), especially for the pre-service teachers. They need to get more itemized explanations about the theory and the strategy of SLA in teaching activities in every course meeting, especially practical subject matter that fit to be adopted in both contextual and their classroom setting. By understanding SLA theory, it is hoped that SLA Â will bring a major effect on pre-service teacher teaching repertoires.
To make students more engaged and facilitate them to construct their understanding, educational outdoor activities might be considered as an alternative pedagogical strategy in learning and studying  SLA. Through dynamic and engaging learning,  teachers can guide the students to elaborate on some of the most practical SLA theories to be adopted in classroom settings.  In our study, the learning activities are developing teaching materials through posters in order to engage students in learning SLA as well as to encourage students to apply new subject -matter into the actual condition. This activity shows that learning English (SLA) is not limited to a classroom setting but also in students' real life. This will facilitate them to comprehend constructivist approaches in learning where the students build new concepts through their prior and current knowledge (Bruner, 1986).
In response to this, the teacher should consider several elements of the outdoor activity to make it more meaningful for pre-service teachers. As shown in the study, these critical elements are a cognitive challenge, students' prior knowledge, the purpose of the outdoor activity, contextual factors, and the structures that support the learning process. The cognitive challenge refers to the students or pre-service English teacher competency in applying the classroom-learned educational content (e.g. theory of SLA) in relevant real-life context. Students' prior knowledge has discussed that a pre-service English teacher needs to well-mastering the theory and concept of SLA before delivering the strategy to the target students especially in choosing the poster English materials. Â Another consideration is the purpose of outdoor activity in which the students or pre-service English teacher understand the aim of these outdoor activities to the students while the teacher has to comprehend the students' skill and competence. Contextual factors are addressed to the teachers' preparation of both materials and concepts (e.g. teaching strategies) that will be delivered to the students. Besides the materials and contents preparation, the teacher should have put huge consideration on the structures that support the learning process. This phase refers to the teachers who should master the use of technology particularly in creating posters (e.g. choosing an appropriate font, color, and theme). Those learning activities introduced pre-service teachers to the fact that pre-teaching needs more resources and practical knowledge as it can create a well-prepared teacher and engage the students that learning English is not boring yet beyond fun.
CONCLUSION
SLA offers a lot of theory or recent research related to the acquisition of a second language which might be an alternative solution for teaching English in Indonesia, which so far has tended to adopt a form base. Form base is a language learning that focuses on lexicogrammatical mastery which tends to be rigid. As a result, learning a second language (such as English) is seen as just knowledge: English lessons are mostly memorizing vocabulary and grammatical formulas. The emphasis of learning on grammar allows students to be able to compose sentences correctly and easily understood by the interlocutor, however, this kind of learning if not balanced with a more communicative approach will make students afraid to speak or write. Something that teachers really avoid. In contrast to the traditional approach, SLA offers a more student-friendly way of acquiring a second language naturally. From this point of view, SLA developed several leading theories such as input theory, output theory, interaction theory, and others.
Thus, this short reflection article emphasizes on the five students' reactions during the study of SLA following its practice. We focus on the five elements such as the students or pre-service English teacher cognitive challenge, students' prior knowledge, the purpose of the outdoor activity, contextual factors and the structures that support the learning process. Following this statement, the data were collected through a written guided reflection approach based on the real students' feelings while taking SLA on their learning activities as the students and pre-service English teacher. The dominant element goes to the  "cognitive challenge" where all of the five students experienced the same result in creating teaching materials through posters such as they were challenged and difficult to elaborate between the theory and practice. Another similar finding is "students' prior knowledge" has positioned an important element to consider as it catalyzes students to accomplish their outdoor activity tasks. By those empirical findings, several elements have bolstered the students or pre-service English teachers to prepare the creative materials following the strategies. Thus, the implication from the present study is to encourage the pre-service English teacher to build more challenging and creative activities in second language acquisition particularly in conducting outdoor activities in order to give the students some experimental experience which is an essential ingredient for students' meaningful and comprehensive learning process (Dewey, 1933)
