What assessment allows for engagement to be tracked through the duration of interaction for each item presented?

The correct answer is the single-item duration assessment, which is designed to track engagement by measuring the amount of time an individual interacts with a single stimulus. This method provides a detailed view of how long a person remains focused on each item, allowing practitioners to assess preferences based on sustained interaction rather than just initial responses. By observing the duration of engagement, practitioners can gain insights into which items hold the individual's attention for longer periods, indicating stronger preferences.

In contrast, other assessment types such as free-operant preference assessments involve offering multiple items to choose from and monitoring selection without a focus on timing for each individual item. Paired-stimulus assessments focus on the individual's choice between two items at a time, providing choice data rather than duration data. Multiple-stimulus assessments present several items simultaneously for selection, but they do not track how long a person engages with each item once they have selected it. The unique aspect of the single-item duration assessment lies in its meticulous approach to measuring interaction time, thereby effectively pinpointing preferences through engagement duration.