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Do you wish there was a better way to diagnose language and literacy disorders—including dyslexia?

Would you like to compare oral and written language abilities directly?

Do you wish you had a better way to explain test results?

Then it’s time to discover the Test of Integrated Language and Literacy Skills™ (TILLS™), the groundbreaking assessment that tests oral and written language skills in students ages 6–18 years. Developed by a team of highly respected experts—Nickola Nelson, Elena Plante, Nancy Helm-Estabrooks, and Gillian Hotz—TILLS features 15 extensively researched subtests, all fine-tuned to meet strong psychometric standards using scientific evidence gathered in numerous pilot studies and trials. Through the subtests, you’ll assess and compare the full range of students’ oral and written language and literacy skills. The resulting scores and the clear, at-a-glance TILLS Profile help you identify and track a student’s strengths and weaknesses—information you’ll use as you develop custom-tailored interventions to improve students’ communication skills.

TILLS At-A-Glance

What does TILLS do?

TILLS has been standardized for three purposes:
  • to identify language and literacy disorders
  • to document patterns of relative strengths and weaknesses
  • to track changes in language and literacy skills over time

How does TILLS assessment work?

Through a series of 15 subtests in key areas like speech perception and production, decoding and spelling, comprehension, and story recall, TILLS lets you capture the full picture of students’ oral and written language skills. TILLS was developed so you can administer the entire test, single subtests, or combinations of them in one or more sessions.

How long does TILLS take?

Comprehensive assessment with TILLS can typically be administered in just 90 minutes or less.

Who uses TILLS?

TILLS can be administered by speech-language pathologists, special educators, reading specialists, learning disability specialists, neuropsychologists, educational psychologists, and other educational specialists trained in individualized test administration who can diagnose dyslexia and other disorders.

When was TILLS Published?

TILLS was published in 2016.

Which students should be assessed with TILLS?

TILLS is ideal for evaluating students between the ages of 6 and 18 years:
  • suspected of having a primary (specific) language impairment
  • suspected of having a learning disability, specific reading disability, or dyslexia
  • with existing diagnoses associated with difficulties in oral and/or written language
  • who are struggling with language, literacy, or social communication skills

Who developed TILLS?

The four authors—Nickola Nelson, Elena Plante, Nancy Helm-Estabrooks, and Gillian Hotz—have been working as a team for more than a decade. They’re highly respected for their test-building skills and evidence-based work in the field of language and literacy assessment. Learn more about the TILLS Authors

Have more questions?

Check out our complete FAQs and even submit a question of your own!

TILLS Benefits


More comprehensive assessment.

TILLS is the only test that assesses both oral and written language with a unique framework that shows how these skills relate to each other.

More accurate diagnosis.

The manual provides diagnostic accuracy in “age bands” meaningful to the development of language and literacy skills. That means you’ll have the evidence base you need to determine if test scores reflect typical or impaired performance.

One test is best.

With TILLS, you get the full picture of oral and written language skills with just one test kit. Because you’re not administering items from multiple tests, you can compare results in different areas and know that your results are psychometrically sound.

Flexible and convenient.

TILLS is designed to work with your schedule. You can administer all 15 subtests or choose the ones most relevant to individual students. You can do them in one session, two one-hour sessions, or even two 45-minute sessions.

Powerful TILLS profile.

TILLS profiles give you an at-a-glance understanding of your students’ strengths and needs—something other tests can’t offer. These profiles help you communicate with others, pinpoint what to work on, diagnose and recognize profiles of disorders, and easily track changes in specific areas of concern.

A true time-saver.

If you’re an experienced clinician, you can administer TILLS in 90 minutes or less. (It can also be chunked into several sessions.) You’ll spend less time testing and more time helping students. The time you do spend testing will be meaningful and relevant to understanding your students’ needs.

TILLS Technical Data

Many other tests don’t provide adequate information on diagnostic accuracy—or if they do, it’s often for a single group of students with a wide age range. But TILLS tested sensitivity and specificity across the full age range covered by the test. Each TILLS subtest meets strong psychometric standards using scientific evidence gathered in pilot studies and field trials, a national beta trial, and a standardization study with more than 1,200 students. Diagnostic accuracy data are broken down into nine different “age bands” meaningful to the development of language and literacy skills:

    Age Groups Sensitivity

  • Sensitivity in 6-year-olds84%
  • Sensitivity in 7-year-olds84%
  • Sensitivity in 8-year-olds97%
  • Sensitivity in 9-year-olds83%
  • Sensitivity in 10-year-olds81%
  • Sensitivity in 11-year-olds82%
  • Sensitivity in 12-year-olds83%
  • Sensitivity in 13-year-olds84%
  • Sensitivity in 14- to 18-year-olds87%

    Age Groups Specificity

  • Specificity in 6-year-olds82%
  • Specificity in 7-year-olds86%
  • Specificity in 8-year-olds100%
  • Specificity in 9-year-olds81%
  • Specificity in 10-year-olds81%
  • Specificity in 11-year-olds82%
  • Specificity in 12-year-olds100%
  • Specificity in 13-year-olds86%
  • Specificity in 14- to 18-year-olds87%

    Screening Sensitivity of the Student Language Scale

  • Sensitivity in teachers' ratings90%
  • Sensitivity in parents' ratings85%

    Screening Specificity of the Student Language Scale

  • Specificity in teachers' ratings90%
  • Specificity in parents' ratings83%
You can find a full report on the research and technical data behind TILLS in the TILLS Technical Manual.
The standardization research for the TILLS was supported by the Institute of Education Sciences (IES), U.S. Department of Education, through Grant R324A100354 to Western Michigan University, but the opinions are those of the authors and publisher. No endorsement by the federal government is implied.

Want to learn more about the powerful research and data behind TILLS?

Read this excerpt from the Technical Manual, and get the facts about TILLS validity, sensitivity, and specificity.