Which of the following best describes MSWO (multiple-stimulus without replacement) preference assessment?

• A. A method where items are presented one at a time, and the individual chooses a single item only.
• B. A method where items are presented in pairs, and the participant selects the preferred item from each pair.
• C. A method where multiple items are presented simultaneously and once chosen, the item is not replaced in the set.
• D. A method that measures tolerance to delayed reinforcement.

Answer: (C)

MSWO emphasizes quickly deriving a preference ranking by having several items available at once and letting the individual choose one. After a selection, that chosen item is not replaced, so in the next trial the person chooses from the remaining items. This process repeats until all items have been selected or a stopping point is reached, producing a clear order of preference. The design is efficient because you compare many items within relatively few trials and still obtain a relative hierarchy of value.

Presenting items one at a time and requiring a single choice describes a single-stimulus or sequential approach, not MSWO. Pairing items and asking for a preferred item from each pair describes a paired-stimulus method. Measuring tolerance to delayed reinforcement is about response to delay, not about determining item preferences.