Welcome to our latest guest article on Rob Williams Assessment’s key Psychometric test design skills.
What are the most important Psychometric test design skills?
How IRT and DIF can be used
- Standardizing psychometric tests
- Testing effect sizes
Item response theory skills, such as DIF analyses
IRT is a psychometric framework used to standardize and improve the accuracy of standardized tests like the SAT (Scholastic Assessment Test).
Here’s how IRT is applied to standardize the SAT:
Item Calibration psychometric skills
- IRT involves calibrating each test item (questions) based on how difficult or discriminating they are.
- This psychometric test design process helps assign a statistical value to each question, indicating its level of difficulty and how well it differentiates between high and low ability test-takers.
Psychometric Test Equating skills
- IRT allows for the equating of different versions of the SAT over time.
- This means that as the SAT is updated or modified, IRT helps ensure that scores from different versions of the test are comparable.
- Psychometric Test equating helps maintain the consistency and fairness of the SAT across different administrations.
Adaptive psychometric Test design skills
- IRT skills can be used to create adaptive versions of the SAT. In adaptive testing, the difficulty of questions presented to a test-taker is adjusted based on their previous responses.
- Item response theory skills help in selecting the most informative questions for each test-taker, which can lead to more accurate and efficient assessment of their abilities.
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Score Scaling skills
IRT allows for the transformation of raw scores into scaled scores. Scaled scores provide a standardized metric that allows colleges and universities to compare the performance of applicants from different test administrations. This ensures fairness in the college admissions process.
Item Analysis skills
- IRT helps test developers analyze the performance of individual test items.
- If a question is found to be biased or ineffective, it can be revised or removed from the test to improve its quality and fairness.
Our other Psychometric test design specialists
- Firstly, here are some examples of our specialist situational judgment test designs.
- Secondly, our values situational and competency values-based assessment designs.
- We also specialise in aptitude test design projects.
- Then next our customised leadership assessment projects and pre-employment sift designs.
- Plus, our emotional intelligence assessment designs. and high potential test designs.
- And then next, our top bespoke personality test design projects and our school aptitude test designs.
- Finally, some examples of the bespoke psychometric tests designed recently for clients.

Moderation skills
How are gcse exam grades moderated?
GCSE exam grades in the UK are typically moderated through a combination of internal and external processes to ensure fairness and consistency. Here’s an overview.
Reliable and valid psychometric test design service
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- HiPo assessment designs
- High performing teams assessment
- Coaching skills assessment
- Aptitude test designs
- GBA design
- Leadership assessment design
- SJT design
- Personality test design
- Pre-employment assessment designs
- Psychological safety assessment designs
- Skills development designs
- Bespoke personality test design projects: personality trait test designs or personality type designs.
- Aptitude test designs, which can be numerical reasoning test designs; verbal reasoning test designs; or abstract reasoning test / non-verbal reasoning test designs.
- Finally, some examples of the bespoke psychometric tests designed recently for clients.