This thesis discusses the Effectiveness of Using Authentic Material In Teaching “Giving Instruction” in the Seventh Grade of SMP Muhammadiyah 1 Semarang in the Academic Year of 2014/ 2015). The statement of problems in this study arehow significant is the differences between students’ achievement in writing (giving instruction) that has been taught using authentic materials and taught using created materials in the seventh grade of SMP Muhammadiyah 1 Semarang in the academic year of 2014/2015 and how much effective is authentic material to teach giving instructionin the seventh grade of SMP Muhammadiyah 1 Semarang.The objective of this study is tofind out the significant differences between student’s achievement in writing (giving instruction) that has been taught using authentic materials and taught using created materials in the seventh grade of SMP Muhammadiyah 1 Semarang in the academic year of 2014/2015 and the effectiveness of using authentic material in teaching giving instruction in the seventh grade of SMP Muhammadiyah 1 Semarang.
The population of this research was the seventh grade of SMP Muhammadiyah 1 Semarang in the academic year of 2014/ 2015. Before the researcher chose sample for the research, she gave pre-test to population that consist of VII A, VII B and VII C. Then the test score of pre-test was counted by using homogeneity test. The result was from population that had same variant. It meant that treatment and post test can be conduct to both of class who chosen as experimental group and control group by using cluster random sampling.
This research is an experimental research. It was conducted into two classes; the experimental class (VII A) and control class (VII C). The experimental class was taught by using Authentic Material, while the control class used created material. The researcher gave pre test to class VII B to find out the validity and reliability before the pre test was given to experimental and control class. The formula that was used to analyze the data was t-test. It was used to determine whether there was significant difference between students’ score in experimental and control class or not.
After collecting the data, it was found that the pre-test average scoreof experimental class was 62. 218and the control class was 59. 965. Meanwhile, the post-test average score of the experimental class was 73. 125 and the control class was 62.414. It was obtained that t-test was 6. 663 and the t-table was 2.001for alpha (α) 5%. The t-test was higher than t-table (6. 663 > 2. 001). It meant Ho was rejected and Ha was accepted that there was a significance difference in teaching writing “giving instruction” achievement score between pre test and post test of experimental class which was taught by using authentic materials.
Based on the result, the researcher concludes that Authentic Materials was effective in teaching writing “giving instruction” at SMP Muhammadiyah 1 Semarang in the Academic Year of 2014/2015.