R package SHELF. Implements various methods for eliciting a probability distribution for a single parameter from an expert or a group of experts. The expert provides a small number of probability judgements, corresponding to points on his or her cumulative distribution function. A range of parametric distributions can then be fitted and displayed, with feedback provided in the form of fitted probabilities and percentiles. A graphical interface for the roulette elicitation method is also provided. For multiple experts, a weighted linear pool can be calculated. Also includes functions for eliciting beliefs about population distributions.