estigate ways to improve learning languages including learning English as a foreign language. In Iran, English language education is considered especially important for experts of the other fields. The problem is that students who have received several years of formal English instruction frequently face difficulties to use or remember the words of language, whether in the spoken or written form. You may see someone who has studied 18 to 20 terms in an institute but he/she is unable to express himself/herself in English. The gravity of the situation comes to eyes when, if not many, some technical subjects are not satisfactorily learned until the students study relevant text books and useful materials in English. Most students have problems when they are asked to learn the new words in a single lesson. Some of them who have found the job very difficult will quit the job at the very beginning, and some try to memorize a word list. None of us can forget the tough job of memorizing word lists during the school days. Learning vocabulary in isolation, in a non-meaningful and technical way is useless. So,vocabulary learning is an important matter for learning of foreign language. Most times it is not easy to remember some vocabularies. And because of this matter researchers are seeking for ways to increase student’s learning vocabularies. So, almost all teachers and students have the same opinion with better vocabulary instructions. According French Allen (1983) if teachers use visual and verbal materials, students learning vocabulary will be better than the time when they use other materials. And the writer in the present study researched this study to understand whether this trend is advantageous to students’ learning and improving vocabulary. And also according Nelson et al (1976) the use of visual and verbal materials such as pictures is effective way and it has good results.In summary, this study aimed to investigate the impact of visual and verbal techniques on vocabulary achievement of Iranian high school students in order toimprovestudents’ learning vocabulary skills, stimulate interest for second language learners to increase their level of vocabulary, provide an interesting way for learning vocabulary, and make learners more proficient, andencourage learners for learning vocabulary.
1.1.7. Research questions
This study aims to answer the following questions:
1-What is the effect of verbal techniques (synonymy, exemplification, etc.) on vocabulary achievement of Iranian EFL students?
2-What is the effect of visual techniques (flashcards, pictures, photographs, etc.) on vocabulary achievement of Iranian EFL students?
3-Which one is more efficient? Visualtechniques, verbal techniques or a combination of these two techniques in enhancing vocabulary knowledge of Iranian EFL students?
1.1.8. Research Hypotheses
With regard to the research questions mentioned above, the following hypotheses were made:
H1: There is a positive relationship between verbal techniques (synonymy, exemplification, etc.), visual techniques (flashcards, pictures, photographs, etc.), and combination of these two techniques and enhancing vocabulary knowledge of Iranian EFL students.
H2: There is no relationship between verbal techniques (synonymy, exemplification, etc.), visual techniques (flashcards, pictures, photographs, etc.), and combination of these two techniques and enhancing vocabulary knowledge of Iranian EFL students.
1.1.9. Organization of the study
This study is organized in thesis whit following chapters:
Chapter one (introduction):
Introduction in which the problem of the study, research questions, significance of study are presented .
Chapter two (review of literature):
Literature review in which the paramount issues and influential studies are discussed .
Chapter three (methodology):