What does text complexity involve in reading instruction?

Text complexity is a multifaceted concept that plays a critical role in reading instruction. It encompasses both readability and the depth of ideas presented in the text, making option B the most comprehensive and accurate answer.

Readability refers to how easy or difficult a text is to read, which includes factors such as sentence length, vocabulary difficulty, and text structure. Depth of ideas relates to the complexity of the themes, concepts, and arguments within the text, which can challenge students' thinking and comprehension skills. When educators consider both aspects of text complexity, they can select materials that appropriately challenge students at their respective developmental levels, thereby enhancing their reading abilities and comprehension.

In contrast, focusing solely on the number of words in a text, as suggested by one of the other options, does not provide a full picture of what makes a text complex. Similarly, the length of the reading session or the emotional appeal of a text are important elements in teaching reading, but they do not directly address the broader criteria of text complexity itself, which is crucial for effective reading instruction. Understanding these dimensions enables instructors to better support student learning by aligning texts with their instructional goals.