Validity of guided inquiry-based student worksheets in mechanical waves and thermodynamics

21st century learning, especially in learning physics leads to the achievement of Higher Order Thinking Skills (HOTS). These skills can be achieved with various efforts, both the application of learning models and the use of appropriate learning materials. This study aims to develop a valid guided inquiry-based students worksheet as one alternative that can be done to achieve HOTS. The use of this student worksheet can help improve students’ thinking skills through orientation activities, formulating problems, formulating hypotheses, collecting data, testing hypotheses, and formulating conclusions. This research used the ADDIE model. The validation of this student worksheet is in the fourth stage, namely the development stage, which is carried out after the product is created. The results of the validation analysis by experts showed that the guided inquiry-based student worksheets developed were in the very valid category with an average score of 83.1%. This shows that this worksheet has feasibility in terms of presentation, content feasibility, linguistic, and graphic aspects. The results of this validation can contribute as a basis for developing learning materials, especially supporting the optimization of HOTS.


Introduction
Physics is the part of natural science that studies phenomena from the atom to the cosmic scale, which is accompanied by mathematical proof of the existing theories and laws [1].Testing the truth of theories and laws requires critical thinking to analyze problems and the ability to come up with innovative ideas to solve existing physics problems.This is related to the higher level thinking skills that each individual possesses such as problem-solving skills, critical thinking skills, creative thinking skills and knowledge transfer processes [2] [3].
Implementation of the curriculum in Indonesia improves students' Higher Order Thinking Skills (HOTS).There are four indicators of this ability, namely critical thinking, problem solving, making decision and creative thinking.These skills include the students' ability to analyse, evaluate and design problem-solving processes [4].
Applying HOTS to learning can help students gain skills such as critical, creative and innovative thinking, communication skills, collaborative skills and confidence.These five competencies are included in the learning assessment system in Indonesia, one of which is the national examination [3].A national exam is an assessment of learning outcomes conducted by the government using the same assessment for all schools.These assessments aim to assess the performance of graduates at the national level in specific subject areas.It is also one of the criteria for achieving national education standards within the framework of ensuring and improving the quality of education.
Based on the analysis of the results of the 2018 and 2019 West Sumatra National Physics Exams, it can be concluded that the student's ability to answer questions in the HOTS category for each subject tested is still insufficient.In general, students tended to more easily understand the material about Mechanics.Meanwhile, the materials with the lowest percentage that students could answer correctly were Electricity, Magnetism, Modern Physics, and Waves and Optics [5].
Improving students' Higher Order Thinking abilities can be pursued in two ways, namely the application of learning models and the provision of appropriate assessments [6].The selection and use of the right learning model will greatly determine the success of learning.The model used plays an important role in the learning process, from the first activities to the end of the learning process.By using a systematic model and referencing the four HOTS indicators, students are expected to develop higher-order reasoning skills, particularly when solving physics problems.
The application of the learning model will be more optimal if it is supported by learning materials that contain HOTS indicators in it.The use of learning materials can not only help students obtain information systematically and develop their competence, but also help teachers deliver material programmatically according to the demands of the applicable curriculum [7].One of the most widely used learning materials in schools is student worksheets.The use of worksheets will make it easier for teachers to convey learning activities because everything is presented in a complete, systematic and clear manner [7].This worksheet will help students to be actively involved in collaboration with other students through group work.This worksheet can not only be used in experimental activities, but can also be used for concept discovery activities through group discussions.
One of the innovations introduced in the development of student worksheets is the integration of the learning model syntax into them.This will help both teachers and students to have a more structured learning process.To achieve higher-order thinking skills, such as Curriculum Objectives, the template embedded in this worksheet must support those skills.A learning model that can help achieve HOTS learning is the guided inquiry learning model.
Inquiry means a question or examination or investigation.This model will lead students to find something like what scientists do in organizing knowledge and investigating a principle [8].The guided inquiry learning model involves students in restructuring information and knowledge and helps students to understand concepts [9].In the guided inquiry process, students investigate the questions presented by the teacher using a designed procedure [10].Syntax used in this inquiry learning model is orientation, problem formulation, the formulation of hypotheses, the data collecting, testing hypotheses, and formulating conclusions [11].The implementation of inquiry-based learning model could improve the quality of students' higher thinking skills [12].
The aim of this study is the development of student worksheets based on guided inquiry learning models.This worksheet was developed for the study of physics with the topic of mechanical waves and thermodynamics.This worksheet has steps according to the guided inquiry syntax which are arranged sequentially.

Research Method
This study aims to develop a product through a series of research activities using different methods [13].This research falls under the Research and Development (R&D) framework using the ADDIE model which consists of 5 phases, namely analysis, design, development, implementation and evaluation.This research is part of the third phase of the ADDIE model, i.e. the development phase.At this point, scientists conducted a proof of concept of the product under development.The validity test was performed by evaluating experts to obtain data on the feasibility of the developed product [14].
The data collection instrument in this study was a learning material validation form completed by the validator.The validation was carried out by 3 experts from the Department of Physics of the Faculty of Mathematics and Natural Sciences of the Universitas Negeri Padang.The validity analysis used was a descriptive statistic using a Likert scoring scale.Percentage of the overall grade of the proficiency test, which results from dividing the result achieved by the highest grade: The validity category of the student worksheets determined on the basis of the survey carried out is given in Table 1.
Table 1 Product validity category is assessed based on the final score interval obtained.The product is developed until a minimum value is obtained in the valid category.Even though it has been declared valid, the product is still being revised according to suggestions and input from the validator.

Result and Discussion
The results of this study clearly show the quality of the developed guided inquiry-based student worksheets in terms of validity.Validation items assessed include content suitability based on supporting theory, content suitability based on guided inquiry syntax, content suitability based on higher-order thinking skills indicators, presentation, language, and graphics.
Assessing the validity of a presentation aspect has 5 components.The first component observed is the suitability of learning objectives and indicators with the basic competencies in the curriculum used for Physics subjects in schools.As a second element, the validator also assesses the compliance of the worksheets' construction with the guidelines established by the Ministry of Education in 2008.The structure of the assessed worksheets includes the accuracy of the titles used, the legibility of the instructions, skills to be acquired in the learning process, information to support accessibility, tasks included, work steps and elements of assessment.The third component assessed is the aspect of this presentation, namely the role of worksheets to encourage students in problem solving process and the implementation of practicum activities.In addition, the fourth element observed in the developed worksheet is the possibility of interaction between teachers and students while using this worksheet.Finally, the assessment carried out relates to the clarity of the steps in using the worksheet and its suitability with the guided inquiry model.The average validation results for each aspect of the presentation feasibility are shown in Figure 1.

Figure 1. The Validity Result of Presentation Feasibility
Based on the data from the validity results in Figure 1, we can observe that all components assessed on the aspect of presentation feasibility are already in the valid category.The highest score is found in indicators of suitability and learning objectives used in worksheets with basic competencies in the curriculum.In addition, the developed worksheets follow a standard structure and allow interaction between teachers and students when using them in learning.Although the overall presentation aspect is good, there are some aspects that need emphasis to be highlighted in the designed worksheet.The emphasis that needs to be done lies in problem solving section, the steps of practicum activities, and the syntax for this learning model used.Each of these components needs to be stated explicitly and clearly in the designed worksheet.
The next component of validity assessed is content feasibility.The content validity carried out includes three parts, namely the feasibility of content based on supporting theory, guided inquiry model syntax, and indicators of higher order thinking skills.Content feasibility components based on supporting theory generally include aspects of the suitability of the material on the worksheet with competencies and indicators that must be achieved in learning.In addition, this section also observes the suitability of the learning objectives formulated with learning indicators.In addition, the feasibility of content based on the guided inquiry model syntax also includes several evaluation aspects.In general, the assessed aspects relate to the systematic syntax of the guided query model used and the clarity of the information and instructions given for each of the syntaxes of the guided inquiry model used.Then the assessment of the feasibility component of the content based on the higher-order thinking skills indicators presented in the developed worksheet was also observed.Aspects observed in this section relate to the appropriateness and accuracy of the activities, questions, and content of Worksheet with each indicator of these thinking skills.The validity result of the substantive feasibility component is shown in Figure 2. Based on the data shown in Figure 2, we can conclude that the developed guided inquiry-based student worksheets belong to the valid category, although in terms of supporting theory the validity value is lower than the aspects of the guided inquiry model and higher thinking skills included in the worksheets.The content feasibility component based on the supporting theory on the developed student worksheet can be declared valid by the validator.This value is obtained because the worksheet has met the expected supporting theory criteria.In this section, the indicators made on this worksheet have been developed in accordance with the basic skills to be achieved at the end of the lesson.In addition, the learning objectives that are made describe the methods or steps used to achieve each indicator well.In addition, the material presented has been formulated based on basic competencies, core competencies, and learning objectives that must be achieved after learning.
The content feasibility component based on the guided inquiry syntax has a higher validity score than the supporting theory.The aspects observed were the systematics and the accuracy of the use of any guided inquiry model syntax in the developed worksheet.The availability of guided inquiry syntax in the developed worksheet has a perfect score of 100.This value is obtained because this worksheet has been arranged systematically based on the order of the guided inquiry syntax.
There are 3 syntaxes that have the highest scores, namely orientation syntax, hypothesis formulation, and data collection, with a value of 83.3.Syntax orientation on this learning material contains general information, learning objectives, and phenomena that can encourage students to formulate problems.Furthermore, the syntax of problem formulation is presented in the form of instructions that can encourage students to formulate problems.Then, in formulating hypotheses, this worksheet contains instructions that are clear enough to guide students to formulate a hypothesis provisional answers based on the supporting theories presented.
Furthermore, the guided inquiry syntax which is in the second position is the syntax for testing hypotheses and formulating conclusions with a value of 75 each.The hypothesis testing syntax on this worksheet contains instructions for students to test the correctness of the temporary answers based on the supporting theory and the data obtained.In addition, in formulating conclusions, students are facilitated with clear instructions to conclude the material studied based on the data obtained in the data collection syntax.
The model syntax for guided inquiries with the lowest score is the problem statement syntax with a score of 66.7.This syntax is presented in the form of instructions that are structured to motivate students to formulate problems based on the information or phenomena presented in the orientation The Aspects of Content Feasibility section.Nevertheless, the formulation of this problem is in the valid category.Overall, the feasibility of the content in terms of the availability of the guided inquiry model syntax used ranged from 66.7 to 100.This indicates that the student worksheet is valid in terms of using the model within it.The third aspect observed in the feasibility of the content of the developed worksheets is the indicator of Higher Order Thinking Skills (HOTS).Components evaluated in this section have a value range of 75 to 91.6 with a valid category.This worksheet has been prepared containing HOTS indicators, include indicators of problem solving, decision making, critical and creative thinking.In problem solving section, worksheets are designed to guide students to find and solve problems based on accurate data and information.In the critical thinking section, the worksheet contains questions and instructions that can guide students to find the right information as consideration for determining the right problem solving solution.The content presented on this worksheet also encourages students to generate diverse ideas.This activity belongs to the indicators of creative thinking, where students can find a new innovation to solve problems.Furthermore, the questions presented in this worksheet are arranged according to Bloom's taxonomy level for the HOTS criteria, namely analyze, evaluate, and create [10].
The next validation aspect that is assessed in this study is the linguistic component used in the worksheet.In general, there are 3 aspects that are assessed, including the correct use of Indonesian rules in the sentences, whether the language used is easy to understand and the terminology and physical symbols are consistent.The results of the validation of this linguistic aspect can be seen in Figure 3.

Figure 3. The Validity Result of Linguistic Feasibility
Figure 3 shows the validity value for each linguistic aspect contained in the learning materials.The linguistic aspect is in the valid category with a range of scores obtained between 66.7 and 100.The indicator with the lowest score is the use of symbols and physics terms.This happens because there are several different terms used in learning materials.This aspect has been revised according to suggestions from the validators so that this worksheet does not cause doubts for students and teachers when using it in schools.Meanwhile, the other two aspects observed obtained perfect scores.This is because the language used in this worksheet is clear and easy to understand, and follows a good language structure.
The final assessment component for validity is the graphic component.There are seven aspects that are assessed on this graphic component.The results of the validity in terms of the feasibility of graphics are shown in Figure 4.The Aspects of Linguistic Feasibility Based on the data shown in Figure 4, we can conclude that the observed graphical feasibility aspects are already in the valid category.The seven aspects assessed are in the range of scores of 75 to 91.7.The three components observed have the highest value of 91.6.This component deals with the design and layout in the developed worksheet.This worksheet is designed with a simple but attractive appearance.The image used on the cover is also related to the physics topic discussed in it, so that the cover display represents the content of the material.In addition, the layout used is in accordance with the worksheet design.
In addition, the illustrations, images and photos presented in the worksheets correspond to the material and have an attractive appearance.The color scheme used on the cover sheet and each page of the worksheet is also proportional.However, the use of fonts in the worksheet, both in size and type, has been slightly revised after being validated by the validator.However, the use of fonts in the worksheet is in the valid category with a score of 75.
According to the results of the validity data analysis carried out, the mean validation value of the six validation components is 83.1.This value indicates that the developed student worksheet is in the valid category.The results of the validation performed on all aspects of guided inquiry-based student worksheet development are shown in Figure 5.The Aspects of Graphics Feasibility Overall, all aspects of validity have been above the value of 61 which is the lowest value for the valid category [15].The validity grade obtained is the result of the mean rating of the three validators.The lowest validation value is in the feasibility of the presentation with a score of 78.3.However, this value already exceeds the minimum score for the valid category.The validity aspect with the highest score is the graphic component.This component relates to the structure of the worksheet preparation which includes the layout, color combinations, and the proportionality of the writing used.Furthermore, the linguistic aspects used in this worksheet are also good.This is indicated by the sentences or instructions used in this worksheet to facilitate the use of this worksheet, according to the assumptions of the validator.In addition, the feasibility of the contents of this worksheet is also good, in terms of the supporting theory presented, the use of the guided inquiry model syntax and the availability of HOTS indicators in the same.Thus, this worksheet can be used for the next stage, namely the practicality and effectiveness test.These two tests aim to determine whether this student worksheet, based on guided inquiry, is user-friendly and effective in improving student learning outcomes, particularly in the area of wave mechanics and thermodynamics.
Guided Inquiry-based student worksheets consist of two core competencies, namely the laws of thermodynamics and the characteristics of wave mechanics.It has been developed with multiple attractive colors accompanied by stimuli in the form of realities of daily life, speeches, information usually found around students and cases/problems that improve students' critical thinking and decision-making skills in the learning process.This worksheet is prepared in accordance with the Ministry of National Education (2008), which consists of titles, study instructions, competencies to be achieved, supporting information, tasks and work steps [16].
This worksheet has advantages over others, where this worksheet is arranged based on learning steps using a guided inquiry model.In this guided inquiry model, the teacher plays an important role in directing students to conduct investigations in class.This activity can be done by the teacher by providing structured questions that can guide students to conduct in-depth investigations of contextual phenomena related to the topic being studied [17].Teachers and students actively participate in investigating and determining problem patterns, testing explanations, and evaluating validity data and their conclusions [18].
The inquiry investigation process carried out by students will help them be actively involved and encourage them to build their understanding independently [19].The use of the guided inquiry model is most prevalent in science education, which includes physics.This model can help to improve all The Aspects of Validity aspects of student competence [20].Previous research has also shown that applying guided inquiry model to learning materials can effectively develop skills related to the scholarly process [21].This worksheet should contribute to the higher thinking skills of the students.In line with its pedagogical support role, this worksheet aims to help teachers to organize learning activities in a structured way according to the syntax of the guided inquiry model, which is one of the following that supports the achievement of higher order thinking [6][7] [12].However, the product developed needs to be tested on a wider scale to see if this worksheet can be used for all different school conditions and students.This aims to see whether the products that have been declared valid by experts are practical and effective for various conditions, especially in improving higher-order thinking skills.

Conclusion
Based on the research conducted, guided inquiry-based student worksheets on the material of the law of thermodynamics and mechanical wave properties of class XI Senior High School, they were found to be very accurate with a value of 83.1%.This validity is checked for the feasibility of presentation, content, language and graphics.From this it can be concluded that the student worksheet based on the guided inquiry model is very well suited for use in learning.
The use of guided inquiry-based worksheets is one of the pedagogical innovations that can help teachers and students to carry out each phase of their learning in a systematic way.If the learning materials used are relevant to the models applied in class, and support the attainment of high-level thinking skills, it is hoped that the educational goals of student competency can increase.

Figure 2 .
Figure 2. The Validity Result of Content Feasibility

Figure 4 .
Figure 4.The Validity Result of Graphics Feasibility

Figure 5 .
Figure 5.The Validity Result of Each Feasibility Component