What is the SPM-2? The Sensory Processing Measure, Second Edition explained

The SPM-2, or Sensory Processing Measure, Second Edition, is a questionnaire rating scale that measures how a person takes in and responds to sensory information such as sound, touch, movement, and body position. Published in 2021 by WPS (Western Psychological Services), it is completed by parents, teachers, caregivers, or the person being assessed, which makes it a report of observed everyday behavior rather than a performance test. It is not an IQ test, and it does not measure reasoning ability or produce anything like an IQ score. Only a qualified clinician can interpret SPM-2 results, and the measure itself does not diagnose any condition. This article explains what the SPM-2 measures, who it covers, how its scores work, and how it differs from a cognitive ability test.

The SPM-2 is grounded in "Ayres Sensory Integration" theory, a framework developed by occupational therapist Dr. A. Jean Ayres, who coined the term "sensory integration" in 1963 to describe how people register, organize, and respond to sensory input. According to WPS, the measure provides norm-referenced scores for six sensory systems along with two higher-level integrative functions.

Each of the main SPM-2 forms reports scores on the same set of scales:

• Vision: how the person responds to visual input, such as lights, movement, or visual clutter.

• Hearing: reactions to sounds, including over-sensitivity to noise or failure to notice auditory information.

• Touch: responses to tactile input like clothing textures, messy play, or unexpected contact.

• Taste and Smell: reactivity to flavors and odors, an area the publisher notes is new to this edition.

• Body Awareness: the "proprioceptive" sense, meaning awareness of body position and force, such as pressing too hard or misjudging distances.

• Balance and Motion: the "vestibular" sense, which governs balance, movement, and orientation against gravity.

• Planning and Ideas: "praxis," the ability to conceive, plan, and carry out new motor actions.

• Social Participation: how sensory functioning shows up in everyday social involvement at home, school, or in the community.

A Sensory Total score summarizes overall sensory functioning. Item responses also give clinicians descriptive information about under-reactivity, over-reactivity, sensory-seeking behavior, and perception difficulties within each sensory system.

The second edition expanded the measure across the lifespan. The publisher states that the SPM-2 covers ages 4 months to 87 years through five age levels, each with its own forms. There are 12 main forms in total, and each contains 80 items rated on a four-point frequency scale (Never, Occasionally, Frequently, Always). A main form takes about 20 to 30 minutes to complete.

The Infant/Toddler level (4 to 30 months) includes an Infant Form, a Toddler Form, and a Caregiver Self-Report Form. The Preschool level (ages 2 to 5) and Child level (ages 5 to 12) each pair a Home Form completed by parents or caregivers with a School Form completed by school staff. The Adolescent level (ages 12 to 21) adds a Self-Report Form, and the Adult level (ages 21 to 87) uses a Self-Report Form alongside a Rater Report Form completed by someone who knows the adult well, such as a spouse or family member.

Beyond the main forms, the SPM-2 offers brief environment forms of 15 to 18 items that take about 10 minutes. For school-aged children these cover settings such as art class, the school bus, the cafeteria, music, physical education, and recess. Adolescents and adults can also be rated on driving environment forms. WPS designed the forms to be used together as an integrated system across home, school, caregiving, and community settings, though each form can stand alone. Administration can be on paper or online through the publisher's digital platform, and purchase requires the publisher's highest qualification level, which generally means a professional with advanced training in psychological or educational assessment.

SPM-2 raw scores convert to normalized "T-scores," a type of standard score with a mean of 50 and a standard deviation of 10. Percentile scores are also available. Note that this is a different scale from the familiar IQ metric, which sets the mean at 100 and the standard deviation at 15. On the SPM-2, higher T-scores indicate more frequent sensory-related behaviors, so elevated scores signal greater difficulty.

The SPM-2 also produces a Difference score, abbreviated "DIF," which compares results from any two forms. A clinician can use it to see whether a child's sensory behavior at home differs meaningfully from behavior at school, or whether an adolescent's self-perception diverges from a parent's or teacher's view.

According to WPS, the SPM-2 was standardized on 3,850 typically developing individuals ranging from 4 months to 87 years, with separate normative samples at each age level, and a further clinical sample of 639 people receiving services was used to check that scores distinguish typically developing individuals from clinical groups. The publisher reports median reliability estimates of .86 for internal consistency, .84 for test-retest reliability, and .66 for agreement between different raters. Independent research is beginning to accumulate as well. A 2026 study in the Canadian Journal of Occupational Therapy reported a strong correlation of about .86 between total scores on the SPM-2 Adult Form and another adult sensory questionnaire, supporting the idea that the two instruments tap similar constructs.

The most important distinction is between a rating scale and a performance test. An IQ test requires the examinee to solve problems, and the score reflects demonstrated ability under standardized conditions. A rating scale like the SPM-2 asks an observer, or the person themselves, how often certain behaviors occur in daily life. Both approaches are useful, and they answer different questions. In this respect the SPM-2 resembles other questionnaire instruments such as the Social Responsiveness Scale, Second Edition, which measures social behaviors associated with autism through rater report.

The constructs differ as well. The SPM-2 measures sensory processing and praxis, while IQ tests measure reasoning, knowledge, memory, and processing speed. Even performance tests that involve the visual system, such as the Beery VMI for visual-motor integration or the MVPT-4 for motor-free visual perception, sit closer to the cognitive domain than the SPM-2 does, because they score what a person can do rather than how a person typically reacts to sensation.

In practice, occupational therapists and school teams often use the SPM-2 alongside cognitive, academic, and adaptive measures. A child referred for evaluation might complete an IQ test with a psychologist while parents and teachers complete SPM-2 forms, giving the team complementary views of ability and everyday functioning.

The SPM-2 has clear strengths: a lifespan age range, multiple raters and environments, a large nationally representative norm sample, and a treatment link through the publisher's Quick Tips intervention strategies for preschool and child levels. Its main limitations deserve equal attention.

First, "sensory processing disorder" is not a recognized standalone diagnosis. WPS itself notes that the DSM-5-TR and the ICD-11 do not recognize sensory processing disorder as an independent condition, even though many clinicians and researchers use the term. Sensory symptoms do appear within established diagnoses; the Centers for Disease Control and Prevention lists hyper- or hyporeactivity to sensory input among the DSM-5 diagnostic criteria for autism spectrum disorder. Second, rating scales depend on the rater. The publisher's reported median interrater reliability of .66 is respectable for this kind of instrument, but it means two observers will sometimes describe the same person quite differently, which is one reason the DIF score exists. Third, the SPM-2 is a screening and assessment aid, and any diagnostic conclusion belongs to a qualified clinician who integrates it with interviews, observation, and other testing.

If your question is about sensory processing, an instrument like the SPM-2, interpreted by an occupational therapist or psychologist, is the right category of tool. If your question is about cognitive ability, you need a performance test with strong norms. For adults 18 and older who want a rigorous online option, the RIOT IQ test was developed by RIOT IQ with psychometrician Dr. Russell T. Warne. The Reasoning and Intelligence Online Test includes 15 subtests across six cognitive indices (verbal reasoning, fluid reasoning, spatial ability, working memory, processing speed, and reaction time), takes about 52 minutes, and reports scores on the familiar mean-100, standard-deviation-15 IQ scale. Like any online measure, it does not replace an individually administered diagnostic evaluation. It provides a carefully built estimate of general cognitive ability.

No. The SPM-2 is a behavior rating scale that measures sensory processing, praxis, and social participation. It does not measure intelligence, and its T-scores are not comparable to IQ scores.

According to the publisher, the SPM-2 spans ages 4 months to 87 years across five age levels: Infant/Toddler, Preschool, Child, Adolescent, and Adult.

WPS requires its Level C qualification, which generally means professionals with advanced training in assessment, such as occupational therapists, psychologists, and related clinicians. Parents and teachers complete forms, but interpretation is the professional's job.

Each of the 12 main forms takes about 20 to 30 minutes, and the brief school and driving environment forms take about 10 minutes.

No single questionnaire diagnoses anything. Sensory processing disorder is not an independent diagnosis in the DSM-5-TR or ICD-11, and while sensory reactivity is one DSM-5 criterion for autism spectrum disorder, diagnosis requires a comprehensive evaluation by qualified clinicians.

The publisher reports that the 2021 second edition expanded coverage from childhood to the full lifespan, added new forms including driving forms, updated the norms with a new nationally representative sample, and added the DIF score for comparing forms.

1. Parham, L. D., Ecker, C. L., Kuhaneck, H., Henry, D. A., & Glennon, T. J. (2021). Sensory Processing Measure, Second Edition (SPM-2). WPS. wpspublish.com

2. Western Psychological Services. (n.d.). Assessing sensory processing patterns. WPS Research Briefs. wpspublish.com

3. Centers for Disease Control and Prevention. (n.d.). Clinical testing and diagnosis for autism spectrum disorder. cdc.gov

4. Mevissen, M., Yu, M.-L., Brown, T., & Reed, K. (2026). The convergent validity between two adult self-report sensory processing scales. Canadian Journal of Occupational Therapy. pmc.ncbi.nlm.nih.gov

5. Botha, M., van der Linde, J., & Mailloux, Z. (2026). Patterns recognized in Ayres Sensory Integration: A scoping review. Brain Sciences. pmc.ncbi.nlm.nih.gov

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