Assessments can be selected to fit your goals. See the section assessment for suggestions. No particular assessments are necessary to implement Seeking Safety, but assessments can be useful if you decide to evaluate outcomes, monitor fidelity, or research your client population.
The section assessment provides several scales, including the Seeking Safety Adherence Scale. Ideas for other assessments are in the chapter on assessment. You can also read published research studies on Seeking Safety (outcomes) to see the assessments others have used.