Development of an Android-Based Mobile Learning Module to Improve the Students Critical Thinking Skills

: Development of an Android-Based Mobile Learning Module to Improve Critical Thinking Skills of Junior High School. This study's purpose to specify the validity, practicality, and effectiveness of an android-based mobile learning module on simple ventures and aircraft to repair critical thinking skills for middle school students. The development of an android-based mobile learning module on the material simple ventures and aircraft is based on requirements for exact teaching materials for 21st-century learning which identically leverage technology, information, and communication. The method utilized in this research is ADDIE model development design which consists of five stages, namely analysis, design, development, implementation


Introduction
Information technology is very important to be implemented in the world of education to balance the speed of development of education with the development of technology and science itself (Mardhiyyah et al., 2022). Implementation of information technology in Indonesian education is very developed, especially in the field of learning media development (Widodo et al., 2021). Science learning is one of the subjects at junior high school level that focuses on disciplines related to process of natural phenomena that occur and their cause and effect (Herowati & Azizah, 2022). Science is knowledge that develops from the experience of natural phenomena and interactions that occur in them (Mardhiyyah et al., 2022). The presence of information in science learning has to verify properly through the reinforcement of students' critical thinking skills with the aim that students can process and understand the information found effectively .
Critical thinking skills are ability and process in understanding concepts, and apply, synthesize, and evaluate information obtained and produced (Ryzal et al., 2020). Ridlo et al. (2019) say critical thinking skills are part of higher-order thinking in addition to creative thinking which plays a role in solving complex problems. Partono et al. (2021), revealed the reason why critical thinking skills are essential to be mastered by students because they are included in the 21st century or 4C skills (critical thinking, communication, collaboration, and creativity) that students have to be able to follow the progress, especially at field of science.
Critical thinking skills students which low are one of discussion topics in Indonesia education, based on PISA (Programme for International Student Assessment) data Indonesia was ranked 72 out of 79 countries with students who completed high-level 4992 questions in Indonesia by 1% of 11% from the average OECD (Organization for Economic Co-operation & Development) scores (Bernando et al., 2022). The low ability to think critically can also be seen in outcome from initial analysis in MTS Negeri 1 Jember. The average critical thinking skill in class VIII B students obtained a score of 6,0. The low ability to think critically is affected from several factors, including the lack of learning innovation from teachers which can be seen from the use of some teaching materials that are still in printed form (Ricu Sidiq & Najuah, 2020). One of the efforts to repair critical thinking skills that can be done by teachers is to develop teaching materials based on digital technology (Rizki et al., 2022).
Teaching materials are learning resource materials that are used by both teachers and students to achieve learning goals (Kosasih, 2021). The selection of right teaching materials allows the continuity in learning process to run optimally (Nana, 2020). The most common types of teaching materials are printed teaching materials and non-printed teaching materials. Printed teaching materials include books, handouts, modules, and student worksheets while non-printed teaching materials can be multimedia. Based on the interview results, in learning science class VIII B in MTS Negeri 1 Jember using package books, LKS, PowerPoint (PPT), and Youtube videos as teaching materials. Most of these teaching materials are included in the type of printed teaching materials so they have disadvantage of not being able to present movements and exposure to linear material (Prastowo, 2018). The use of teaching materials tends to be less attractive to students because it is monotonous so it is required to develop teaching materials, one of which is the module.
Learning modules are units of learning activities that have been designed to assist students to achieve learning purposes. The module is learning unit that can operate alone (Mahardika et al., 2021). Currently, many modules have been developed into several forms, one of which is e-module. E-modules are digital teaching materials used to help students learn with the help of computers or androids (Rosidin et al., 2022).
Modules in digital form are learning resources that contain materials, methods, and limitations on how to evaluate with a systematic and interesting design to achieve learning objectives (Rizki et al., 2022). Digital modules can be packaged in mobile form so that they can be adjusted to your needs. Mobile learning or Mlearning is a type of learning that provides educational content and materials supported by the use of wireless tools such as smartphones (Faisol, 2022). Learning using mobile learning with smartphones is hoped to prompt learning so that students can utilize technology simultaneously (Almaiah et al., 2022). The implementation of learning using smartphones can have a positive impact on cognitive, metacognitive, and affective students where smartphones can turn learning into an experience (Prima et al., 2022). Based on this description, researchers developed an android-based mobile learning module at ventures materials and simple planes to increase critical thinking skills of middle school students. This development research aims to test validity, practicality, and effectiveness of mobile learning modules.

Method
This research is development research with ADDIE model which has five stages, including analysis, design, development, implementation, and evaluation. The research procedure can be seen in Figure 1. The subjects of this research were 32 students of class VIII B in MTS Negeri 1 Jember. Data collection instruments in this research were used (1) validation sheets, (2) implementation observation sheets, and (3) critical thinking ability tests. The validation sheet serves to discover validity of a product developed and product improvement suggestions obtained from three validators. The implementation observation sheet serves to determine the practicality of developed product filled by three observers. A critical thinking skill test is a test used to specify the effectiveness of a product in requirement of critical thinking skills of middle school students.

Data Analysis
The data analysis techniques are (1) validity test, (2) practicality test, and (3) effectiveness test. Validity assessment data is a form of quantitative data which includes content validation and construct validation covering material aspects, presentation aspects, language aspects, and graphic aspects with a scale of 1-4 where each scale has a different category. The score obtained is then calculated as the average score of each aspect using the equation taken by Nesri & Kristanto, 2020 as follows.

= 100%
(1) Information: V : percentage.of. validity TSE : total.score achieved TSM : total.score maximum After obtaining validity percentage result, then the result is compared with the validity category based on the corresponding criteria. This validity criterion was adopted from Nesri & Kristanto, 2020 as presented in Table 1. The practicality of product is retrieved from observation in implementation of learning. Practicality assessment data is a form of quantitative data with a scale of 1-4 where each scale has a different category. The scores obtained are then analyzed by counting average score of each learning activity using equations taken by Nesri and Kristanto (2020), as follows.

= 100%
(2) Description: P : percentage of practicality TSE : total.score achieved TSM : total.score maximum After obtaining the result on percentage of practicality, then the results are compared with the practicality category based on the corresponding criteria. This practicality criterion was adopted from Nesri and Kristanto, 2020 as. presented in Table 2. The effectiveness test consists of two analyses, namely the analysis of critical thinking skill test and the analysis of student response questionnaire. Analysis of critical thinking skill tests using N-gain calculations to specify the increase in students' critical thinking skills. The N-gain formula by Hake (1998), is as follows. Description: (g) : score average gain which is normalized Spost : score average tes end learners Spre : score average initial test learners Smax : score maximum ideal Once the scores are normalized, then the results are compared with the N-gain category based on the criteria adopted by Hake, 1998, presented in Table 3.
The analysis of student response questionnaires was calculated using equations taken from Khairiayah (2018), as follows.

= 100%
(4) Description: RS : percentage of learner response TSE : total score achieved TSM : total score maximum After the results of student response questionnaire are analyzed, then the results are compared with the category of student responses based on the appropriate criteria. These student response criteria were adopted from Khairiyah, 2018, as presented in Table 4.

Result and Discussion
The development of mobile learning modules empowers communication and information technology on learning concepts that have benefits in availability of teaching materials that can be retrieved every time and interesting visualizations (Prima et al., 2022). Development of mobile learning module using ADDIE 4994 model with a description of the stages as follows.

Analysis Stage
The analysis stage is aimed at identifying needs before developing a product. The analysis conducted includes an analysis of student needs, curriculum analysis, product analysis, and goal analysis. Through the analysis of student needs, it is known that the teaching materials used by class VIII B MTs Negeri 1 Jember have not utilized modules, but are limited to science package books, PowerPoint, and Youtube videos. According to students, this makes the learning atmosphere feel monotonous.
Curriculum analysis to find out the curriculum that applies in schools so that researchers can adjust the sources of content and technology that will be used in learning. The curriculum used by MTs Negeri 1 Jember has currently revised 2013 curriculum. Product analysis to customize features in teaching materials to suit the needs of learners. Teaching materials developed by researchers can be used practically in a variety of circumstances. Analysis of objectives to determine learning objectives based on indicators of critical thinking ability with venture material and simple aircraft.

Design Stage
Design stage to design a product appropriate to the results from analysis. Android-based mobile learning module has an output android smartphone application that can be accessed anytime and anywhere. The first step in design stage is to create a module design using Canva so that the content looks more attractive. Mobile learning is made using codulars, from design generation to programming data to produce interactive teaching materials.

Figure 3. Cover and main menu
The opening is cover as the first display that appears. The main menu is a display to go to a page that student wants. The learning tool consists of basic competencies, learning objectives, and concept maps. Learning activities are divided into learning materials, practice questions, and practicums. The more section consists of a summary of learning materials, a glossary, and a profile of the developer.

Implementation.Stage
Implementation stage includes the assessment step at android-based mobile learning module by validators and test stage of a large class of 32 students. The validation results and observation results are as follows. Based on validation results by three validators in. Table 5, an average percentage of 92% was retrieved on validity of the contents with category of highly valid. 4995 The validity of content is used to determine the suitability of content and material developed in the teaching material with learning competencies and learning objectives (Hutama, 2016). The validity on material aspect, it obtained a percentage of 88% with category of highly valid. Android-based mobile learning module is following venture materials and simple aircraft whose indicators are adjusted to the indicators of critical thinking skill therefore the learning objectives to be achieved are improving critical thinking skills. This was also explained by Hendri et al. (2021), that valid digital modules must have basic competencies (KD) and subject matter with the development of clear learning objectives so that students can easily understand.
Presentation aspect retrieved an average percentage of 95% with category of highly valid. Validation on presentation aspects is used to evaluate the design of teaching materials developed so that the teaching materials have their characteristics (Hutama, 2016). The characteristic of an android-based mobile learning module is an application-shaped module with integrated use of digital tools and sources making teaching materials have advantages that are expected to repair student's critical thinking skills. Meanwhile, at graphing aspect, it obtained an average percentage of 93% with category of highly valid. Graphic aspect on module is inseparable from the suitability of the cover layout, color composition, graphics, layout, and synchronous visuals as well as layer design that must be considered (Febriyanti & Ain, 2021).
Language aspect obtained an average percentage of 92% with category of highly valid. Language validation to evaluate the language applied to write of teaching materials so that they have a good level of readability are communicative, and according to the rules, can make it easier for students to understand the content on teaching materials (Ridlo et al., 2020).
Based on this description, development of.androidbased mobile learning.module teaching materials is declared valid because it has met the feasibility of content and constructs so that android-based mobile learning modules are worthy of being used as science.teaching.materials. This is following the research of Sa'diyah (2021), which stated that digital-based emodules show validation results that are included in the category of valid and theoretically feasible. In addition, research by Purnamasari et al. (2020), also mentioned that development of valid.android-based interactive emodules can facilitate students to learn independently and is an innovative learning resource. The results of observations in.implementation of.learning using an android-based mobile learning module showed that learning activities using androidbased mobile-learning module in preliminary stage received a percentage of 95%, a core stage of 94%, and a closing stage of 98% so that it got a total percentage of 95%. This percentage shows that learning using androidbased mobile-learning modules is highly valid. This is following the statement of Feriyanti (2019), the existence of e-modules is good for increasing the participation of students in learning process.
Android-based mobile learning modules are practically used in learning. These results are following the research of  the results of practicality data analysis obtained a value of 95% which means android-based mobile-learning modules are included in highly practical category and can be operated in learning. Zukhrufurrohmah et al. (2017) stated that teaching materials are practical if the observation results show that the level of learning implementation is included in a high category and teaching materials developed can make it easier for teachers when teaching and easy to understand students.

Evaluation.Stage
Evaluation stage is to provide an evaluation of effective products that have been developed. Data on the results of effectiveness were obtained through digital literacy tests and student response questionnaires. The elaboration Figure 7.   Table 7, N-gain value reaches 0.63 which belongs to the medium category. Results of N-Gain analysis on any question indicator can be seen in Table  8.  Ramdani et al. (2020), explained critical thinking skills indicators with excellent categories are found in explanation indicators, while the indicators with the lowest scores are analysis indicators, this is because questions with explanation indicators require more students' memory to provide appropriate information as explanations and reasons to answer questions correctly. Students who can explain the relationship between problem-solving concepts clearly and precisely can be said to have met the analysis indicators, while to meet the explanation indicators, students can provide reasons for conclusions drawn clearly and precisely (Purbonugroho et al., 2020).
The increase in students' critical thinking skills shows that android-based mobile-learning modules are effectively used in learning. The design of android.based mobile-learning module is tailored to needs of students so that it can attract students to operate it. This is relevant to the research of Prianbogo & Rafida (2022) which concluded the development of android.based electronic modules in form of codular applications as mobile learning are very feasible to be applied as a valid, practical, and effective learning medium. Gani et al. (2021), stated that.android-based.modules are highly practical to use and make it easier for students to study. A similar learn was conducted by Rismayanti et al. (2022), who stated codular based e-modules on androids are interesting and feasible to use and can repair the critical thinking skills of middle school students. The.results of questionnaire analysis student responses can be seen in Table 9, percentage reached 95.51%. This means that the response of students is very positive to android-based mobile learning modules. This happens because the products are developed to support the learning process by making learning more interesting, adding variety to learning, and making it easier for students to understand concepts (Rismayanti et al., 2022). Fun learning causes a very positive response from learners which has an impact on learning interests, classroom activities, and improved learning outcomes. Based on analysis of student response questionnaires, both in interest, response, interest, satisfaction, and motivation to get a very positive response so that android-based mobile learning modules are effectively used in learning process.

Conclusion
Android-based mobile learning modules get an average validity of 91.83% and belong to very valid category. The practicality obtained an average percentage of 95.48% and was included in very practical category. The effectiveness level is reviewed from Ngain score of critical thinking skill test and student response. The average N-gain of critical thinking skill tests was 0.63 with moderate categories. The average percentage of student response questionnaires was 95.91% with a very positive category. Based on this, android-based mobile learning modules are effectively used as teaching materials for science learning in middle schools. 4997 Zainur.R. All authors have read and agreed to the published version of the manuscript

Funding
This research received no external funding

Conflicts of Interest
The authors declare no conflict of interest.