



How the IDEX® California Exam is Developed
To develop, administer, and score the IDEX® California Examination, CCIDC works with Meazure Learning, a professional testing company that specializes in the development of certification and licensure exams. CCIDC follows accepted procedures for developing such exams and carefully document each step in the test-development process.
CCIDC updated its Practical Analysis in 2021 to identify current knowledge and skills that define a minimally competent professional in interior design. During the practice analysis process, the psychometricians from Meazure Learning and International Code Council (ICC) work with a panel of subject-matter experts to define the overall practice areas and distinct tasks, knowledge and skills required for competent performance.
CCIDC uses the practice analysis to develop a ‘blueprint’ or template, for the IDEX® California Exam. Information from the analysis is used to determine the importance of each area of practice or task and is then translated into the percentage of questions allotted a given area in the multiple-choice sections of the exam.
The question-writing process uses psychometricians from Meazure Learning Corporation and the International Code Council (ICC), along with subject experts to ensure the appropriate content and form. All exam questions are written and reviewed by volunteer subject-matter experts in interior design, architecture, building officials and fire marshals who are trained in developing questions and problems for the exam. During and after development these experts review all of the questions to ensure they adhere to accepted principles for multiple-choice questions and design problems, as well as grammatical and usage conventions.
Questions accepted for use in the exam are judged, by consensus of the volunteers, to meet the following standards:
- The knowledge tested by the question is essential for competent interior design and the protection of public health, safety, and welfare.
- The knowledge tested by the question is either moderately or extremely important in assessing competent interior design.
- A correct response to the question would moderately or clearly differentiate adequate from inadequate performance for the competent interior designer.
- The question has a verified reference.
- The question is appropriate for the competent interior designer.
- The answer or solution is correct.
- The answer or solution can be defended if necessary.
- The other answer choices are incorrect, but plausible to those without sufficient knowledge.
To verify the validity and quality of exam questions, CCIDC pretests new questions and problems before including them as scored items on the exam. Candidates do not know which questions are scored or unscored. The pretest results are analyzed statistically to ensure the quality and reliability of the overall exam.
The IDEX® California Exam is created by selecting the appropriate number of questions from each content area, as specified in the test blueprint. A panel of subject matter experts works with Meazure Learning & ICC psychometricians during test assembly and validation to ensure maximum quality (in accordance with the considerations listed above) and an appropriate mixture of content.
The draft exams are reviewed by Meazure Learning psychometricians, testing experts and subject matter experts for technical accuracy and to ensure integrity.
An exam must have a defensible, criterion-referenced passing score. The score that separates candidates who pass from candidates who fail must be based on the minimum competence required to protect the public from harm. CCIDC works with Meazure Learning psychometricians to determine this cut score, which we define as the level of an interior designer’s ability to practice independently (without supervision) in a manner that will protect the public health, safety, and welfare.
The exam administration procedures for the IDEX® California Exam ensure consistent, comfortable testing conditions for all candidates, including live online proctoring. Test administration guidelines specify a process for admitting candidates into the exam room, verifying their identity, providing security, allotting testing times, and other important considerations. Testing facilities meet Meazure Learning guidelines for security, proper room size, ventilation, restroom facilities, accessibility, and noise control. Test administration proctors are thoroughly trained in the requirements for administering the test.
Following each exam administration, Meazure Learning psychometricians conduct systematic analysis studies to ensure the proper function of each question and problem and of the test as a whole. Psychometric analysis also includes extensive reliability analysis as well as other studies that evaluate the quality of the exam.









