Usually, a correct answer earns a set number of points toward the total mark, and an incorrect answer earns nothing. However, tests may also award partial credit for unanswered questions or penalize students for incorrect answers, to discourage guessing. For example, the SAT removes a quarter point from the test taker's score for an incorrect answer.
For advanced items, such as an applied knowledge item, the stem can consist of multiple parts. The stem can include extended or ancillary material such as a vignette, a case study, a graph, a table, or a detailed description which has multiple elements to it. Anything may be included as long as it is necessary to ensure the utmost validity and authenticity to the item. The stem ends with a lead-in question explaining how the respondent must answer. In a medical multiple choice items, a lead-in question may ask "What is the most likely diagnosis?" or "What pathogen is the most likely cause?" in reference to a case study that was previously presented.