Designing a Vocabulary Size Test Based on Persian Core Lexicon

Testing is an important part of teaching any language and an important part of learning a language. Vocabulary size test is one of placement tests that is used to determine the level of lexical knowledge of language learners .This test is designed in many languages and its vacancy was felt in the Persian. To design a vocabulary size test, one must pay attention to the frequency of the words used and linguistic corpus. The corpus used in this research is including paper texts in seven different fields. To design this test for each group of words, 80 questions were designed and arranged from high-frequency to low-frequency. The questions were computerized and the link was sent to the language learners. 130 people answered the test. 45 language learners also participated in the retest. Analysis showed that the mean test scores increased with the language level of the language learners. Skewness and Analysis of variance also showed that the data distribution was normal and the difference between the mean scores of different groups of novice, elementary, intermediate and advanced in this test was significant. Calculation of the correlation between test scores and retest scores indicates a strong correlation and test reliability. The interpretation of the scores of different language levels was also done and it was determined that each language level of the score can determine which language level. Based on this research, it can be said that the vocabulary size test can determine the language level of language learners as a placement test.