The language for school reading: CALS


Why so many adolescents struggle with reading?

To help answer why so many adolescents struggle with literacy, Paola Uccelli in collaboration with Christopher Barr and Emily Phillips Galloway proposed the construct Core Academic Language Skills (CALS) and developed and validated a novel assessment, the CALS Instrument. Several studies now show that individual differences in CALS help explain upper elementary and middle school students’ reading comprehension levels. The delineation and testing of CALS as a component of literacy advances the scientific understanding of language and literacy relations and offers a precise skillset to guide the design of educational interventions.

Current Project

Core Academic Language Skills (CALS) Assessment Design and Development


CALS construct

CALS refer to a set of language skills that are useful for reading texts across school content areas, but are not typically used in informal conversations among adolescents. In the words of our teacher/researcher collaborator, Melanie Allen, "CALS is the name we use for a group of skills that students need in order to understand complex academic texts, even though they don’t necessarily need them for everyday conversations."


CALS instrument

The CALS Instrument is a novel test designed to assess the language skills that support school literacy across content areas in mid-adolescents (grades 4 to 8). The CALS Instrument has two forms, each of which can be group-administered in sessions of 50 minutes, using either a pencil or a digital format:

  • CALS-Instrument-Form 1 for 4th-6th grade (α =.90)
  • CALS- Instrument-Form 2 for 7th-8th grade (α =.86)

The CALS Instrument is vertically equated and normed for English proficient students attending US public schools in grades 4-8.  This theoretically grounded and psychometrically robust test includes eight tasks: Connecting Ideas, Tracking Themes, Organizing Texts, Breaking Words, Comprehending Sentences, Identifying Definitions, Interpreting Epistemic Stance Markers, and Understanding Metalinguistic Vocabulary. Items include a range of formats: multiple choice, matching, reordering fragments, or short written responses.

The CALS Instrument is presently available for use by educators and researchers as a research instrument upon request, CONTACT USWe have used results from the CALS Instrument in workshops with teachers to raise awareness of the importance of core academic language skills and to bring researchers and practitioners together to reflect about implications for instruction. Studies that use CALS results to inform pedagogical practices are currently ongoing in the U.S., Brazil and Chile.

What have we learned from our CALS research?

English CALS in the US

We have administered the English CALS Instrument to about 7,000 mid-adolescents in grades 4 to 8 across several studies. Our results reveal striking individual differences in students’ CALS which in turn predict their reading comprehension levels (Uccelli et al, 2015; Barr et al, 2019; Phillips Galloway et al., 2019).


Funding. This research was supported by the Institute of Education Sciences of the U.S. Department of Education through grant R305F100026, which was awarded to the Strategic Education Research Partnership as part of the Reading for Understanding Research Initiative. The opinions expressed are those of the authors and do not represent the views of the institute or the U.S. Department of Education.

Spanish CALS in Latin America

The development of the Spanish CALS construct and instrument was led by Paola Uccelli and Alejandra Meneses from the Pontificia Universidad Católica de Chile, with the support of Christopher Barr and Emily Phillips Galloway. The Spanish CALS Instrument or Evaluación de Lenguaje Académico (ELA) was guided by the English CALS research, but it is not a translation of the English version. The Spanish CALS was developed and validated in Chile with about 800 Spanish-speaking mid-adolescents (grades 4-8) attending schools with different socio-economic compositions. By now, the Spanish CALS has been administered to about 2,000 students across Santiago (Chile), Lima (Peru) and Medellín (Colombia). Analogous to the English CALS results, we found marked individual differences in students’ language that help explain the variability in reading comprehension levels between grade 4 and 8 (Meneses et al., 2017).

Funding. The CALS research in Chile was supported by a grant from the David Rockefeller Center for Latin American Studies as part of the Harvard–Chile Innovation Initiative awarded to Paola Uccelli and Alejandra Meneses and from CONICYT 2013, and FONDECYT REGULAR 1150238 awarded to Alejandra Meneses in Chile. The CALS research in Colombia and Peru was supported by a grant from the David Rockefeller Center for Latin American Studies at Harvard University awarded to Paola Uccelli and by a Dean’s Venture grant from the Harvard Graduate School of Education awarded to Felipe Barrera-Osorio, Sarah Dryden-Peterson and Paola Uccelli as part of the Leaning for All project.

Portuguese CALS in Brazil

The development of the Portuguese CALS construct and instrument was led by Paola Uccelli with Beatriz Cardoso, Nicole Paulet and their team from the Laboratório de Educação, in São Paulo, Brazil and with the psychometric support of Christopher Barr.  The Portuguese CALS instrument or Avaliação da Linguagem Acadêmica (ALA) was guided by the English and Spanish CALS research, but also it was developed and validated with  2000 students in grades 4, 6 and 8 from ten schools in São Paulo. Consistently with findings in English and Spanish, We find considerable individual differences across and within grades that help to explain differences in reading comprehension achievement, even when controlling for word recognition skills and sociodemographic characteristics.

Funding. The CALS research in Chile was supported by a grant from the Lemann Foundation as part of the Learning for All project awarded to Paola Uccelli (PI) and Felipe Barrera-Osorio and Sarah Dryden-Peterson as part of the Leaning for All-Brazil project.



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