Do the various DESSA response options on the Likert scale need to be defined?

Overview

This article explains that Aperture Education does not provide set definitions for each DESSA response option because providing a definition of the frequency options would not necessarily make the ratings any more accurate, given that raters will ultimately base their rating on their recollections and general impression. It also provides Aperture Education's recommendations on how to guide raters who have questions about the meaning of each response option.

Can you define the DESSA response options (e.g., Rarely, Frequently) for raters?

When raters complete the DESSA, they are typically reflecting on a student’s behavior over the past four weeks and selecting the option based on their general impression. Providing a definition of the frequency options would not necessarily make the ratings any more accurate, given that raters will ultimately base their rating on their recollections and general impression. For example, even if “Frequently” were defined as once a day, raters do not actually record the number of times they see the behavior and then go back over the previous four weeks and calculate the average number of times a student engaged in that behavior per day. They still rely on their general impression of the student’s behavior.

Additionally, not all the behaviors on the assessments have the same base rate. In other words, students generally engage in some of the behaviors more frequently, while others are more rare occurrences. Raters take these differences into account when completing the assessments. Support for this recommendation comes from the high reliability of the assessments, meaning that raters generally complete the assessments in a consistent manner without having the Likert scale response options defined.

If you are asked about the meaning of the Likert scale options, the authors recommend making it clear to raters that their interpretation of the frequency terms, whatever that definition may be, should be used consistently when rating students.

If raters are not sure about how to rate a student most appropriately, it may also be helpful to put the frequency labels right into the question when thinking about the item and reflecting on which statement most accurately reflects their observations of the student.

Following is an example for an item that reads “cooperate with peers or siblings”.  The rater might say, “Maria occasionally cooperates with peers or siblings” or “Maria frequently cooperates with peers or siblings.”  After hearing both statements and reflecting, the rater should feel more confident selecting the appropriate frequency option for that item.