Effect of Tutorial Giving on The Topic of Special Theory of Relativity in Modern Physics Course Towards Students’ Problem-Solving Ability

A Special Theory of Relativity handbook has been successfully arranged to guide students tutorial activity in the Modern Physics course. The low of students’ problem-solving ability was overcome by giving the tutorial in addition to the lecture class. It was done due to the limited time in the class during the course to have students do some exercises for their problem-solving ability. The explicit problem-solving based tutorial handbook was written by emphasizing to this 5 problem-solving strategies: (1) focus on the problem, (2) picture the physical facts, (3) plan the solution, (4) solve the problem, and (5) check the result. This research and development (R&D) consisted of 3 main steps: (1) preliminary study, (2) draft I. product development, and (3) product validation. The developed draft product was validated by experts to measure the feasibility of the material and predict the effect of the tutorial giving by means of questionnaires with scale 1 to 4. The students problem-solving ability in Special Theory of Relativity showed very good qualification. It implied that the tutorial giving with the help of tutorial handbook increased students problem-solving ability. The empirical test revealed that the developed handbook was significantly affected in improving students’ mastery concept and problem-solving ability. Both students’ mastery concept and problem-solving ability were in middle category with gain of 0.31 and 0.41, respectively.


Introduction
Special theory of relativity consisted of the following topics: Newtonian relativity, Einstein's postulates, Lorentz coordinate transformation, simultaneity and the relativity of time, length contraction, time dilation, twins paradox, relativistic doppler shift, Lorentz velocity transformation, relativistic momentum and relativistic energy [1,2,3].As the matter of fact, many students face difficulty in solving problems on the topic of the special theory of relativity. When the students were given problems that were slightly different from the given examples, they are generally unable to solve those problems. Therefore, it is important to introduce explicit solving strategy-based tutorial to help students' difficulty in solving problems.The tutorial underlines the systematic strategies to solve the problems. It does not only stress on the "given" and "questioned", but also lay emphasis on (1) focus on the problem, (2) picture the physical facts, (3) plan the solution, (4) solve the problem, and (5) check the result [4]. An excellent approach to increase the students problem-solving ability is tutorial giving [5,6]. A tutorial is learning and instruction program to help students during taking lectures by means of guided self-learning.
Some previous studies showed that to simultaneously (a) make students become effective problem solvers and (b) master the concepts are a two-goal that is hard to reach. Even by instructional model, there are still many students find difficulties in solving problems [7], and their mastery concepts are relatively low [8]. Combining the active learning and problem-solving strategies to the modern physics students can enhance the students mastery concept and their problem-solving ability [9,10] This research and development are mainly aimed to (1) develop tutorial handbook on the topic of Special Theory of Relativity, (2) investigate the effect of the tutorial giving on the students mastery concept, (3) investigate the effect of the tutorial giving on the student's problem solving ability, and (4) measure the student's problem solving ability at Special Theory of Relativity.

Development Tutorial Handbook
To develop tutorial handbook product, a research design by means of research and development (R&D) was applied. Basically, there are 3 main steps for R&D approach [11]: (1) preliminary study which consists of literature study and survey, (2) product development in terms of draft product arrangement, judgment (expert validation), and trial field testing, (3) product validation. In this present study, we only restricted to the step (1) and (2).
The experimental procedures are described as follows: (1) preliminary study; in this step, an investigation was focused on the learning problems that were faced by students during taking the modern physics course. From the investigation, it was known that 80% of the students found difficulties in solving problems of modern physics. According to this preliminary study, a handbook to guide students in the tutorial was then chosen to implement. (2) draft product development; in this step, a tutorial handbook was created with the following 10 component specifications: (a) introduction, (b) learning objectives, (c) explanation, (d) problem examples and the solutions based on 5 explicit solving strategies, (e) summary, (f) problems, (g) solutions to the problems, (h) scoring method for problem solving, (i) physical constants and important, and (j) references. The tutorial handbook was also completed with "for readers" section in order to help students be easy to use and learn. (3) judgment (validation by experts); this is an assessment activity to evaluate the developed tutorial handbook. This was done to increase the theoretical validity of the products. The judgment was done by 2 physics experts by means of 1-4 scoring scale questionnaires. 4 means very feasible, 3 means feasible, 2 means less feasible, and 1 means unfeasible. The judgment was performed before the trial field testing. (4) trial field testing; in this step, the tutorial handbook was tried to limit the number of students to know the students responses including clarity of language usage, a sequence of materials, consistency of notation usage, availability of images to make the concept clearer. The students responses to the tutorial handbook content were gathered by questionnaires with scale 1 to 4; 4 = excellent, 3 = good, 2 = fair, and 1 = poor. The vision for the final product was based on the students' responses.
The collected data in this present study are material feasibility, students' response, and problemsolving ability. The value of the data was analyzed by the following mathematical expression.
(1) where N = grade, SD = score, dan SM = maximum score. The grade criteria for those data are given bellow.

Trial Field Testing of Tutorial Handbook
The effect of tutorial giving on the students' mastery concept and problem-solving ability was evaluated by means of Pretest-Posttest Control-Group Design [11] and designed as depicted in Table 1. Acceptance/rejection of null hypothesis is based on the criteria as given in Table 2. The amount of increment of the students' problem-solving ability was analyzed by average normalized gain, i.e. the ratio of average actual gain and maximum of average gain given by the following equation [12]: With category: < > is high for < > larger than 0.7 < > medium for < > of 0.3 to 0,7 < > low for < > smaller than 0.3

Expert Validation Result
The draft of the special theory of relativity handbook was validated by 2 experts to examine its feasibility. The validation result is depicted in Table 3. According to the validation result, it can be inferred that the average material feasibility was 95.5 with excellent qualification. The effect prediction of the tutorial giving on providing an opportunity to the students to exercise to solve problem systematically and structurally following the given 5 steps of problem-solving was 100 with excellent qualification. The effect prediction of the tutorial giving on the students' problem skill ability was perfectly 100 with excellent qualification.

Students' Response Result
Students' response on the handbook content is given in Table 4. Based on Table 4, it is clearly seen that the students' response on the special theory of relativity handbook content was 87.5 with excellent qualification. The effect prediction of the tutorial handbook on giving the students opportunity to exercise their problem-solving ability was 90 with excellent qualification. The effect prediction of the tutorial handbook on the students' motivation was 85 with excellent qualification. The effect prediction of the tutorial handbook on the students' self-learning was 87.5 with excellent qualification.

Students'Problem Solving Ability
Students' problem-solving ability in the special theory of relativity is tabulated in Table 5. From Table 5, the students' problem-solving ability in the special theory of relativity was on average of 88 sith excellent qualification. The excellent handbook feasibility indicated that the handbook has good reliability. Both experts and students were in good agreement that the handbook tutorial on improving students' problem ability had a positive effect, which were indicated by excellent qualification. Therefore, the tutorial giving can increase the students' problem-solving ability as previously proposed by Pride, et al.

Students'Mastery Concept
The effect of the tutorial giving on the student's mastery concept was evaluated by comparing their grades for the experimental and control classes as depicted in Table 6. From Table 6, it can be revealed that the experimental and control classes had the similar initial ability. The experimental and control groups had increased of conceptual understanding of 10.4% and 2.8%, respectively. The experimental group had a gain of 0.3 with medium classification, meanwhile the control group had a low classification. It is because the students in the experimental group had extra time to study during tutorial giving.The effect of the tutorial handbook usage on the increasing of the students' conceptual understanding was evaluated by t-test analysis, as summarized in Table 7.  Table 7 showed a significant different between the experimental and control groups in terms of the students' conceptual understanding. It revealed that the tutorial handbook usage in the modern physics course may give a positive effect on the students' conceptual understanding, even though in medium classification. It can be increased by means of providing students with the summary task before starting the class.
The effect of the tutorial giving on the student's problem-solving ability was evaluated by comparing their grades for the experimental and control classes as depicted in Table 8  According to the information in Table 8, the increasing of students' problem-solving ability in experimental group is 16.1% and control groups decrease 2.6%, respectively. It is because the more time available for students of the experimental group to do some exercises than that of the control group. The gain for the experimental group was 0.41, meanwhile, a negative value of gain was detected for the control group.
The effect of the tutorial handbook usage on the topic of the special theory of relativity on the students' increasing of problem-solving ability was evaluated by t-test as depicted in Table 9. The t-test result on the students' problem-solving ability in the special theory of relativity showed significance different between experimental and control groups. It revealed that the tutorial giving can give positive effect in increasing the students' problem-solving ability with medium qualification. More exercises can be given to the students to provide them better problem-solving ability.

Conclusion
A tutorial handbook on the topic of the special theory of relativity with excellent feasibility and response from students has been successfully developed. The tutorial handbook was arranged to increase students' problem-solving ability and mastery concept with excellent qualification. In addition, the tutorial handbook could motivate students to have self-learning awareness. The empirical t-test showed that the tutorial of the special theory of relativity assigned a positive effect to the students mastery concept and problem-solving ability. The students' mastery concept and problem-solving ability obtained a gain of 0.31 and 0.41 with medium classification, respectively.