Pengembangan Modul Berbasis Multipel Representasi dengan Bantuan Teknologi Augmented Reality untuk Membantu Siswa Memahami Konsep Ikatan Kimia

A good understanding of the three levels of chemical representations is required to understand the concepts of chemical bonding. However, most students are difficult to understand chemical bonding topics due to the abstract concepts and the learning resources used don’t fully integrate the three levels of chemical representations. Therefore, learning resources that cover all of the chemical representations and visualize the abstract concepts are needed. The purpose of this study is to determine the level of validity and responses of teachers and students to the developed chemical bonding module based on multiple representations assisted by AR technology. This type of research is research and development that refers to the ADDIE instructional design model. The instrument used in this research is the sheet of validity and the response questionnaire. The collected data were analyzed using percentage analysis techniques. The product of this research is a chemical bond module based on multiple representations and an augmented reality chemistry simulator of chemical bonding application. The results of the expert's validation show that the average percentage of content, media, and language validity respectively are 99, 95, and 97% with very valid criteria, so that it can be used in the learning process. In addition, teachers and students gave a very good response to the product with a percentage of 90 and 87% consecutively. These findings indicate that the modules assisted by AR technology could support the chemistry teachers to explain the chemical bonding topic and help students visualize the abstract concepts of chemical bonds

Location-thinking, value-thinking, and graphical forms: combining analytical frameworks to analyze inferences made by students when interpreting the points and trends on a reaction coordinate diagram

Reaction coordinate diagrams (RCDs) are chemical representations widely employed to visualize the thermodynamic and kinetic parameters associated with reactions. Previous research has demonstrated a host of misconceptions students adopt when interpreting the perceived information encoded in RCDs. This qualitative research study explores how general chemistry students interpret points and trends on a RCD and how these interpretations impact their inferences regarding the rate of a chemical reaction. Sixteen students participated in semi-structured interviews in which participants were asked to interpret the points and trends along provided RCDs and to compare relative reaction rates between RCDs. Findings derived from this study demonstrate the diversity of graphical reasoning adopted by students, the impact of students’ interpretations of the x-axis of a RCD on the graphical reasoning employed, and the influence of these ideas on inferences made about reaction rate. Informed by analytical frameworks grounded in the resources framework and the actor-oriented model of transfer, implications for instruction are provided with suggestions for how RCDs may be presented to assist students in recognizing the critical information encoded in these diagrams.

PENGEMBANGAN BAHAN AJAR KIMIA DASAR BERBASIS CONCEPTUAL CHANGE TEXT PADA MATERI REDOKS

DEVELOPMENT OF TEACHING MATERIALS BASED ON CONCEPTUAL CHANGE TEXT ON REDOX MATERIALS FOR BASIC CHEMICALS ON REDOX CONCEPTAbstractThe problem in this study is that there are still many students who have difficulty learning basic chemical concepts and experience misconceptions. One way to overcome student difficulties in understanding the concept of chemistry is to provide quality learning media. This study aims to produce learning media in the form of quality teaching materials. The teaching materials developed are chemical teaching materials based on Conceptual Change Text (CCT). The research data were obtained from the results of validation of teaching materials from experts and the results of a questionnaire distributed to 30 students. This research was conducted using the R&D method with the research subjects being teaching materials and students. Based on the data generated in this study, it was found that the development of CCT-based teaching materials when viewed from the aspects of content feasibility, presentation feasibility, language assessment, multiple chemical representations assessed by some experts, it can be concluded that the teaching materials developed are good and suitable for use in the field with some improvements with an average validation value of 4. Besides, a limited test was also carried out on students of the teaching materials that were being developed and students responded well to the teaching materials because it could help them understand the average value of 85. AbstrakPermasalahan dalam penelitian ini adalah masih banyaknya mahasiswa yang mengalami kesulitan dalam belajar konsep kimia dasar dan mengalami miskonsepsi. Salah satu cara untuk mengatasi kesulitan mahasiswa dalam memahami konsep kimia adalah menyediakan media pembelajaran yang berkualitas. Penelitian ini bertujuan untuk menghasilkan media pembelajaran berupa bahan ajar yang berkualitas. Bahan ajar dikembangkan adalah bahan ajar kimia berbasis Conceptual Change Text (CCT). Data penelitian diperoleh dari hasil validasi bahan ajar dari para ahli dan hasil angket yang disebarkan kepada 30 orang mahasiswa. Penelitian ini dilakukan dengan metode R&D dengan subjek penelitian adalah bahan ajar dan mahasiswa. Berdasarkan data yang dihasilkan dalam penelitian ini diperoleh hasil bahwa pengembangan bahan ajar berbasis CCT jika dilihat dari aspek kelayakan isi, kelayakan penyajian, penilaian bahasa, penilaian multiple representasi kimia yang dinilai oleh beberapa ahli dapat disimpulkan bahwa bahan ajar yang dikembangkan sudah baik dan layak digunakan di lapangan dengan beberapa perbaikan dengan rata-rata nilai validasi 4. Selain itu juga dilakukan uji terbatas terhadap mahasiswa terhadap bahan ajar yang sedang dikembangkan dan mahasiswa merespon dengan baik bahan ajar tersebut karena bisa membantu mereka dalam memahami dengan rata-rata nilai 85. konsep.

Molecular representations in AI-driven drug discovery: a review and practical guide

The technological advances of the past century, marked by the computer revolution and the advent of high-throughput screening technologies in drug discovery, opened the path to the computational analysis and visualization of bioactive molecules. For this purpose, it became necessary to represent molecules in a syntax that would be readable by computers and understandable by scientists of various fields. A large number of chemical representations have been developed over the years, their numerosity being due to the fast development of computers and the complexity of producing a representation that encompasses all structural and chemical characteristics. We present here some of the most popular electronic molecular and macromolecular representations used in drug discovery, many of which are based on graph representations. Furthermore, we describe applications of these representations in AI-driven drug discovery. Our aim is to provide a brief guide on structural representations that are essential to the practice of AI in drug discovery. This review serves as a guide for researchers who have little experience with the handling of chemical representations and plan to work on applications at the interface of these fields.

Students’ competence in translating between different types of chemical representations

Meaningful understanding of chemistry, among others, includes the ability of an individual to think simultaneously at macroscopic, submicroscopic and symbolic levels, and this presupposes the competence to translate between different types of chemical representations. In this study, we investigated 11th grade Greek students’ and 3rd year undergraduate chemistry students’ ability to translate chemical representations from one level of chemistry (e.g., submicroscopic) into another (e.g., symbolic) concerning the basic chemical concepts: “chemical element”, “chemical compound”, “aqueous solution” and “solid state of matter”, which have already been taught in earlier grades. We followed a mixed method design in which both quantitative and qualitative research instruments were developed and used. These instruments consisted of multiple choice and open-ended questions, which included real pictures (macroscopic), symbolizations and submicroscopic diagrams. Various representations of the three types were given to the students and they were asked to choose or to construct an equivalent one of a different type. Our results showed that the 11th grade students’ ability to move across the three levels of chemistry is very low, while the 3rd year undergraduate chemistry students’ performance is higher but not satisfactory. In addition, the results obtained from the application of “translation questions” between the three levels of chemistry highlighted many students’ alternative conceptions, some of which still persist among the undergraduate students. The students showed lower performance in translations concerning the concepts “chemical compound” and “aqueous solution” than those concerning the concepts “chemical element” and “solid state of matter”. The students also showed the lowest level of performance in translating the submicroscopic representations into the symbolic ones. Generally, our results indicate that translating between different types of chemical representations is a very challenging task, which depends on students’ conceptual understanding.

Representations of chemical phenomena in secondary school chemistry textbooks

The difficulties encountered by students in learning chemistry range from human factors to the intrinsic nature of chemistry. To enhance students’ understanding of chemistry, there is a wide consensus within the community of chemistry educators on the importance of and need to integrate different levels of representations in chemistry teaching and learning resources. As learning resources, textbooks are ubiquitous and usually readily available to both students and teachers. Therefore, this study investigated how chemical phenomena are represented or depicted in secondary school chemistry textbooks. We adopted a rubric developed by Gkitziaet al.(Gkitzia V., Salta K. and Tzougraki C., (2011), Development and application of suitable criteria for the evaluation of chemical representations in school textbooks,Chem. Educ. Res. Pract.,12, 5–14) to analyze the textbooks for types of representations; relatedness of chemical representations to text; and the appropriateness of captions. The results indicated the dominance of symbolic representations, followed by sub-microscopic, then hybrid and multiple representations. In all three textbooks, there was no evidence of mixed representation. While many of the chemical representations were completely related to the texts, some were unlinked. The germaneness of suitable captions in textbooks is in the explicit, brief and concise explanation that captions give to an entire representation. While our results indicated that more than half of the representations had suitable captions, there was evidence of representations that were problematic and had no captions. The implication of these results for students’ cognitive load, and the need for textbook-users to explore alternative resources that depict phenomena in 2D or 3D representations are discussed.

Learning continuous and data-driven molecular descriptors by translating equivalent chemical representations

Translation between semantically equivalent but syntactically different line notations of molecular structures compresses meaningful information into a continuous molecular descriptor.

Hydrogel-Tissue Chemistry: Principles and Applications

Over the past five years, a rapidly developing experimental approach has enabled high-resolution and high-content information retrieval from intact multicellular animal (metazoan) systems. New chemical and physical forms are created in the hydrogel-tissue chemistry process, and the retention and retrieval of crucial phenotypic information regarding constituent cells and molecules (and their joint interrelationships) are thereby enabled. For example, rich data sets defining both single-cell-resolution gene expression and single-cell-resolution activity during behavior can now be collected while still preserving information on three-dimensional positioning and/or brain-wide wiring of those very same neurons—even within vertebrate brains. This new approach and its variants, as applied to neuroscience, are beginning to illuminate the fundamental cellular and chemical representations of sensation, cognition, and action. More generally, reimagining metazoans as metareactants—or positionally defined three-dimensional graphs of constituent chemicals made available for ongoing functionalization, transformation, and readout—is stimulating innovation across biology and medicine.

EXAMINATION OF CHEMICAL REPRESENTATIONS IN TURKISH HIGH SCHOOL CHEMISTRY TEXTBOOKS

The aim of this research was to examine the chemical representations that are present in Turkish high school chemistry textbooks. Content analysis was the method of analysis. Four chemistry textbooks, which were commonly used in Turkey, for each grade (i.e., from 9th to 12th), were selected. When evaluating the representations, a rubric including five main criteria was used: (1) type of representation, (2) interpretation of representations’ surface features, (3) representations’ relatedness to text, (4) properties of representations’ caption, and (5) degree of correlation between subordinates comprising a multiple representation. The results of the research revealed that the chemical representations used in the textbooks are mainly macroscopic, symbolic, and hybrid. Majority of the representations had explicit surface features and appropriate captions. Moreover, they were completely related to the text. Most of the multiple representations had sufficient links between their subordinates. Recommendations for textbook writers and future research are provided. Keywords: chemistry textbooks, chemical representations, generic qualitative research, content analysis.