Text difficulty refers to the level of complexity in written text that may impact a reader's ability to comprehend and understand the material. This research area focuses on factors such as vocabulary, sentence structure, and overall complexity of language that may affect a reader's ease of reading and comprehension. Researchers in this field may study various methods for measuring text difficulty, such as readability formulas, as well as strategies for adjusting text difficulty to better suit the needs of different readers, such as children, second language learners, or individuals with learning disabilities.