Techniques for determining a maturity level of a text string may be provided. For example, the text string may be associated with an electronic book or story, script or closed captioning of a movie or television show, or other text associated with media. The system may analyze the text string to identify actions in the text (e.g., concepts of death, degree of violence, etc.), story complexity (e.g., number of characters, linear/non-linear story flow, etc.), vocabulary (e.g., unique words, complexity of terms, etc.), and other metrics to determine the objective maturity level associated with the text string. The maturity level and/or references to electronic books associated with the particular maturity level may be provided to users and/or used in additional processing and analysis.