Implementation of Augmented Reality (AR) android based in learning

Augmented reality is a technology that offers the ability to combine the virtual content with the real world. Augmented reality is divided into two, which is desktop based and mobile (android) can be used as a media in learning. The presence of augmented reality is a solution for abstract and complex learning. We are collected several journals related to augmented reality from a variety of sources, and acquired as many as 57 articles in the span of eight years between 2010 and 2018, and 28 of them in accordance with this research topic. We found a variety of research methods used to obtain the data for the implementation of augmented reality as a learning media, methods used include observation, questionnaires, surveys, pre-test and post-test, interview, video recording, and documentation. The resulting impact also varied, ranging from student motivation, student performance, student understanding, and the effectiveness of learning.


Introduction
The development of instructional media has started in the middle 20th century [1]. Learning media is very helpful to delivering learning content [2], one of the media that is in demand by students is the Augmented Reality (AR) and give a different contribution to student learning experiences and they are attitudes [3]. Augmented Reality is part of the development of instructional media that utilize Information and Computer Technology (ICT) [1]. Augmented Reality is application can projected digital images to the real world [4]. Augmented Reality is a technology that can be applied in by several area including education [5], by utilizing the incorporation of virtual and real content, AR can help provide an understanding of learning methods to children with disabilities [6]. AR offers to the users or to the students closer to the real world of things to be learned about [7].
With offers between the virtual world and the real world then AR can provide solutions for students in the learning of abstract and complex [8]. Augmented Reality development in recent years has been examined empirically in the laboratory development [4]. Augmented Reality is growing very rapidly and is widely used in several fields of science such as construction, engineering, field management, making AR the right choice for the learning process [9]. Potential of AR is able to change the way people interact and understand the environment around [10], but we as educators cannot always rely on computer applications in terms of providing learning material because it will affect the development of students' cognitive abilities [7].
Research on the use of Augmented Reality learning media in schools can have a significant impact on the ability of students to understand the concept of learning science as students learn to use instructional media Augmented Reality [11]. Augmented reality proved to be more suitable for use in learning have a higher degree of difficulty than the use of paper in the learning process is evidenced by the results obtained by students 'learning and students' ability to complete the tasks assigned [12].
The purpose of this study is to describe the types of research methods used to obtain the data for the implementation of augmented reality as a medium of learning, as well as to provide information about the impact that appears after using augmented reality as a learning medium.

What is Augmented Reality
Generally Augmented Reality can be defined on three main features: (a) combining of real objects and virtual objects; (b) with Augmented Reality can interact with real-time; (c) provide accurate images with three-dimensional projection [13]. In another study Augmented Reality is defined as the state in which the real context coated dynamically in the context of virtual information [14]. Augmented Reality adds, supplement or improve the existing realities, by adding elements of computational results obtained from the input data that can include audio, video, graphics or GPS data [15,16],

Features, systems and applications Augmented Reality
Developed of augmented reality can be used software display, input and tracking devices, and computer [17]. These types of screens that can be used is a head mounted displays (HMD), mobile devices (Android, Tablet PC). Augmented Reality System is divided into the image display system and locationbased systems [18]. Augmented Reality-based images are subdivided into two categories: marker-based and marker-less base tracking.
Marker based Augmented Reality requires a special label, such as Quick Response Code (QRC), to position the 3D object in the drawing. While the marker-less augmented reality, every part of the picture can be used as a target to place virtual objects [19]. At this time, along with advances in technology, increased use of AR applications developed based on Android [17].

Method
Articles were identified by literature review exploring the Web of Science database, Taylor and Francis online, Google Scholar, and Science Direct. By entering the keyword "Augmented Reality in Education". As a result, gained as much as 57 articles in the span of eight years between 2010 and 2018. Of the 57 articles were obtained and then read and filtered again really related to Augmented Reality in education and learning process. From 57 we obtained 28 articles. Of the 25 articles analysed and coded using a spreadsheet.

Coding scheme
Coding using four main categories of approaches in the analysis of the article is as follows:  Basic data: author, year of publication, journals, place of study.  Methods: research approaches, methods, themes, data collection techniques, methods of analysis, research.

Data collection methods used
The method is often used to obtain research data on the implementation of augmented reality in learning is observation, questionnaire, survey, pre-test and post-test, interview, video recording, and documentation. The method used to obtain the data in the implementation of augmented reality adjusted with the aim of the researchers, observation and surveys are used to obtain initial data that describes the conditions in which augmented reality will be implemented [20]. Questionnaires are mostly used to obtain data on the response of the user augmented reality [21]. Pre-test and post-test was used to look at learning outcomes before and after implementation of augmented reality in the learning [22,23]. Interviews can be used to obtain the data after the implementation of augmented reality, the interview can be done to the students and teachers [24]. The video recording was used to observe the student's attitude during the implementation of augmented reality for teaching and learning activities [25]. And documentation used to obtain data such as pictures or video during the implementation of augmented reality in the teaching and learning activities [26].

The impact that come from implementation of AR in learning
In this section discusses the impact that caused as a result of the implementation of augmented reality. The impact of implementation of augmented reality in learning related to the motivation of learners [27], performance of learners [28], understanding learners [11], effectiveness of learning [29] and many more. not all studies produce significant impacts, sometimes when the use of augmented reality in research does not show a significant impact on learning [30].

Conclusion
Augmented reality in its development is now divided into two categories, namely augmented realitybased desktop and mobile-based augmented reality (android). In lessons, augmented reality is often used as a learning medium in order to help students to understand the material that is abstract and complex. During implementation, many of the methods used by researchers to obtain the desired results, ranging from interviews, to documentation. Using method must be adjusted to the type of research, both qualitative and quantitative research. The results of the study found that the impact of the application of augmented reality for learning was very positive, although in some aspects no impact was found