It has been widely reported in various research journals about the difficulties of students in studying vectors and their application in physics. For this reason, research has been conducted which aims to identify misconceptions about vectors and application in physics concepts and the use of graph lines in the teaching of physics. Therefore research has been carried out based on the use of representation. The research method uses MOMBI which emphasizes the treatment of class formative assessment models. The study was conducted on 39 pre-service teacher students who had studied Mathematical Physics and Mechanics. By comparing the pre-test and post-test scores, the results of the study are that the decrease in score is incorrect in terms of the concept of drawing tail-tips or head-magnitude vectors from 89.7% to 38.4%, and the decrease in score is not correct in terms of implementation in determining the vector of the center of gravity from 92.3% to 35.8% and then the decrease in score is incorrect in terms of the concept of determining position vector from 97.4% to 45%. In conclusion, the use of graph lines in the teaching of vectors has positively increased students’ comprehension abilities related to vector concepts and their application in physics concepts. The recommendations of the research results, namely the importance of teaching materials and university physics reference books, include graph lines in the picture of concepts that use vectors, such as vectors of force, momentum, torque and so on.

The use of semiotic resources in developing abilities and skills in physics problems is very important. PIMCA learning model (Presentation, Idea Mapping, Conceptualization and Formative Assessment) introduced and developed by Cosmas Poluakan is the focus of this research. The purpose of this study was to analyze student difficulties on learning the refraction using the PIMCA model based on multi-representation (MR). The type of research used experimental research with one group pretest-posttest design. The research was conducted in the Department of Physics, Manado State University, with 23 students as respondents. The test instrument used for this research has been validated. After processing and analyzing the data, the pretest average score was 15.9 and the posttest average score was 60.2. These results indicate that even though there is an increase in the average proportion of mastery of the refraction of light concept, generally students still have difficulty drawing the angle of incidence, direction of refraction and the position of refraction for the arrangement of 2 mediums. The results of this research recommend that in order to understand the concept of refraction, the use of the PIMCA model needs to provide more practice questions.

Research on the physics learning of electric charge has been carried out using MR-SR (Multiple Representation and Semiotic Resources). The research aims to find out the outcomes of student learning using the PIMCA learning model (Presentation, Idea Mapping, Conceptualization, and Assessment formative) introduced and developed by Cosmas Poluakan. The research was conducted at the Department of Physics, Manado State University, with 22 pre-service teacher students as respondents using the One Group Pre-test-Post-test Design. The instruments used in the form of pre-test and post-test which have been tested and validated. The research implementation stage starts from the pre-test, and then the implementation of physics learning follows the 4 steps of the PIMCA model. The results of data processing and analysis obtained an average pre-test score is 18,88 and an average post-test score is 75,16. There was an increase in concept mastery. In the idea mapping stage only 2 concepts are correct to drafting concept mapping, 6 are correct from 10 concepts that were used as references. PIMCA MR-SR learning model is very effective in helping students find and understand the correct concepts of physics. The use of the PIMCA MR-SR as a new model in the teaching and learning process is very effective in learning physics, mathematics and science or in the STEM area.