Researchers have developed a new test to quickly measure how well Thai speakers know their vocabulary. The test, called the Thai Lexical Decision Task, asks participants to decide whether a word is real or not. The study found that the test is a reliable way to measure how well someone knows their vocabulary, and it's also related to other measures of language skills and cognitive abilities. The test worked well even after repeated use, and it was found to be more accurate for older adults and those with more education. This new test could be useful for assessing cognitive abilities in Thai adults and for evaluating language skills before a person has a brain injury or disease.