Contains the answers of 191 California high school
students to the question: "When did you first use marijuana?". An
answer can be an exact age, or "I have never used it", which gives
rise to a right-censored observation, or "I have used it but cannot
recall just when the first time was", which gives rise to a
left-censored observation.
Usage
marijuana
Arguments
format
A data frame with 21 observations and 3 variables:
L: left-end point of an interval-censored time;
R: right-end point of an interval-censored time;
count: number of students in the interval.
source
Turnbull and Weiss (1978). See also Klein and Moeschberger
(1997), page 17.
References
Turnbull and Weiss (1978). A likelihood ratio statistic
fortesting goodness of fit with randomly censored data. Biometrics,
34, 367-375.
Klein and Moeschberger (2003). Survival Analysis: Techniques for
Censored and Truncated Data (2nd ed.). Springer