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Units of Study

Units of Study: Is a popular balanced literacy language program, designed by Lucy Calkins and inspired by Fountas and Pinnell. 


According to the Unit of Study website, the program:

“-help teachers address each child’s individual learning

-explicitly teach strategies students will use not only the day they are taught, but whenever they need them,

-support small-group work and conferring, with multiple opportunities for personalizing instruction,

-tap into the power of a learning community as a way to bring all learners along,

build choice and assessment-based learning into the very design of the curriculum,

-help students work with engagement so that teachers are able to coach individuals and lead small groups.”


The Units of Study website lists 16 studies; However, to the best of my knowledge, only 1 study had a control group and could be used to evaluate the program. A systematic search was also attempted on Education Source; but, due to the ambiguous title of the program 92,915 results were found when searching “units of study”. Therefore, it could not be determined if additional studies existed on the topic, not listed on the company website. 


An independent quasi-experimental study was published, but not peer-reviewed by the American Institute for Research, in 2021. The study included a sample size of 51 treatment group schools equated with 178 control group schools. Despite the fact that the program is offered for K-5, results were only measured for grades 3-5. The precise sample size was not listed within the study. The study was 7 years long. Effect sizes were calculated by the authors, for each year. However, the effect size formula was not identified, which is problematic. Effect sizes consistently went up, the longer the study continued, contrary to most research, as typically longitudinal studies show lower results. All effect sizes were small to negligible. 


To the best of our knowledge, there has only been one experimental or quasi-experimental study conducted on Units of Study. The study showed on average small to negligible results. However, results showed that over long periods of time achievement improved. There are no studies for primary aged students and therefore these results are only applicable to students in grades 3-5. It is important to note the grade, in this context, specifically, because so much of the reading wars debate has focused on grades k-2 and this study does not address these grades. This study does provide evidence that Units of Study might show a small positive benefit for core instruction, over a long enough time horizon, in grades 3-5. 


Normally, I evaluate a program both quantitatively and qualitatively. However, qualitatively evaluating this program is very difficult. Originally, the program was a balanced literacy program; however, the author has recently made many updates to the program to try and better align the program with the Science of reading. This fact might also negate the validity of the efficacy study, as it’s really not the same program, as it was, when this study was done.


I think it is important to neutrally evaluate the changes to see if they actually align with the science of reading. Truthfully, I think there is a lot of anger within the literacy instruction community directed at Lucy Calkins, as teachers feel that they were misled on what the science of reading showed, by her and other people at Heinemann publishing. Consequently, I am sure there are those who would prefer that I give the Units of Study program a bad review, regardless of whether changes were good or not. However, I think that would be not just intellectually dishonest, but morally dishonest. If Units of Study gets bad reviews, despite making good changes, what motivation would other companies have for making positive updates to their programs? 


That said, I think it is also important to make sure that these changes are meaningful and not superficial. As I have previously written, on numerous occasions, the scientific literature shows stronger research outcomes for structured literacy programs, opposed to balanced literacy programs. Typically balanced literacy programs don’t have a phonics scope and sequence, encourage three cueing, don’t use decodables, and embed phonics instruction, within fluency work. I reached out to Lucy Caulkins to get her input on these changes. However, she declined to comment, after reviewing our website. I have done my best to review the curriculum changes, to see if these changes were meaningful. 


Let's start with the good news. The program has removed three-cueing, added a phonics scope and sequence, and added decodable texts. This means that the program now meets the definition of systematic phonics, provided within the NRP report. That said, I do have some concerns, especially with the scope and sequence. 


Firstly, the phonics curriculum is not very explicit. For kindergarten phonics instruction, the only graphemes that I saw specifically mentioned were: m, s, t, n, r, l, a, w, d, o, h, y, i, e, o, i, u, p, b, g, j. It also specifically mentions the following blends and digraphs: tr, ch, ick, ell, uck, og, at, in, it, & an. While the curriculum does say teachers are to teach all basic letter sound correspondences, it does not provide a precise scope and sequence for doing this. I am not a linguist, so I will not comment on the order of these graphemes; however, it does seem very incomplete to me. 


Under the curriculum category of phonemic awareness instruction, there is a great deal of focus on syllable rhyming and syllable segmenting. There is also some focus on phoneme manipulation drills. However, there is minimal focus on blending and segmenting phonemes, within words. This is, in my opinion, problematic, because previous meta-analyses on phonemic awareness have shown the strongest support for instruction that focuses on blending and segmenting phonemes not syllables. 


I am also concerned with how much focus there is on irregular words. Within unit 1 of kindergarten instruction the scope and sequence says: “Locate and read high-frequency words in text. Develop strategies for learning high-frequency words. Learn to read and write new words (me, a the).”  This raises some eyebrows for me. Firstly, I am concerned as to what “strategies for learning high-frequency” words means. Is this just a new way of saying three-cueing? Moreover, I am worried that this means students memorizing giant lists of sight words, before they know any phonics. Now truthfully, contrary to many who find themselves in the “SOR” camp, I am not convinced that the research shows we should never teach “sight words”. However, I do think word instruction should be primarily rooted in encoding and decoding instruction, in kindergarten. The long lists of “sight words” is a staple within balanced literacy programming and indeed there is an entire section of the Units of Study curriculum dedicated to“irregular word instruction”, which seems to encourage just this practice. 


The program has been substantially improved. And in my opinion, is better than some other balanced literacy programs. However, it seems to me that the authors were trying very hard to balance keeping some constructivist elements, while still making changes according to the science of reading. I worry that this curriculum will lead to students trying to memorize large word lists, not connected to the phonics skills being taught. I also worry that the disjointed phonics scope and sequence will lead to grapheme phoneme correspondences being missed. 


This all said, I found grading this program very difficult. I typically give programs that are qualitatively solid, but lack sufficient research a grade of B-. Whereas, I typically give programs that are both qualitatively bad and lack sufficient experimental evidence a C+ or lower. While, I am not convinced that the changes made to Units of Study are enough; I still think the program is better than before and better than many other Balanced Literacy programs. 


Final Grade: C+

Some of the program principles are not supported by the meta-analysis data. The program shows a mean effect size of .19 across 7 years,  which according to Cohen’s guide suggests negligible results. 


Disclaimer: Please note that this review is not peer reviewed content. These reviews are independently conducted. Pedagogy Non Grata, does not take profit from conducting any program review found on this website.  

Written by Nathaniel Hansford: teacher and lead writer for Pedagogy Non Grata

Last Edited 2023-3-05


Terry Salinger and Emily Weinberg. (2021). Evaluation of the Teachers College Reading and Writing Project (TCRWP) Approach. American Institute for Research. Retrieved from <>. 

Heinemann. (2022). Units of Study Research. Retrieved from <>.

Heinemann. (2022). Units of Study Overview. Retrieved from <>. 

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