UPDATE: Student Grouping: What is effective?

This is an updated version of an earlier post, based on new research I included. The decision-tree has been updated! You can find a Google Doc version of this here.

Student Grouping: What is Effective?

How do we leverage student grouping to best promote achievement?

This is a question teachers and administrators ask themselves almost daily. Unfortunately, there are few clear or easy answers. But we can draw out a few general principles from recent research and other sources of knowledge that may help to inform our instructional practice.

It’s important to acknowledge there’s often a steady pressure on teachers to utilize group work. And for some teachers, grouping students by ability can make serving a wide disparity of different levels of students more manageable.

But there’s an often unstated assumption: group work is inherently superior to whole class or independent learning. But is group work always better than other modes of learning?

Tom Bennett, a British behavioral specialist, argues in an article in American Educator, “Group Work for the Good,” that there is little research to suggest group work is better for academic learning. Bennett cautions teachers to only “use group work when you feel it is appropriate to the task you want your students to achieve, and at no other time.

OK, but what are the times when group work is appropriate?

When I first investigated this, a particular passage from Douglas Fisher and Nancy Frey, in their book, Guided Instruction: How to Develop Confident and Successful Learners, struck me:

“. . . an understanding of memory systems has profound implications for instruction, which include creating systematic and intentional scaffolds of students’ understanding rather than leaving them alone to discover information independently. That’s not to say that students should not work together in collaborative learning; they should. We have argued for productive group work in which students interact with one another and generate ideas to produce individual works (Frey et al., 2009). But this work must center on the consolidation and application of content that students already know. It’s neither the time nor the place to introduce new information. Doing so would overload the working memory system and fail to ensure learning(Bold added).

In other words, Fisher and Frey suggest that new concepts and information should not be introduced during group work. Group work should instead be used for reinforcing, consolidating, and applying information students have already been exposed to.

But I later came across another study by Paul Kirschner, John Sweller, Femke Kirschner, and Jimmy Zambrano, “From Cognitive Load Theory to Collaborative Cognitive Load Theory,” that contradicts this. Instead, Kirschner et al. suggest that working as a group creates a collective working memory, and that therefore group tasks should be more complex.

They state, “… learning in a team is more effective than individual learning if the complexity of the to-be-learned material is so high that it exceeds the limits of each individual learner’s working memory.” They furthermore suggest that greater complexity will make the task more engaging for the group: “Collaboration will occur when the task is complex enough to justify the extra time and effort involved in collaborating with others.”

Therefore when assigning group work, ensure that the task is complex enough to warrant collaborative effort.

So we’re engaging groups of kids in complex tasks. Now how do we ensure students are productive during the times when they do work as a group? Here it can be instructive to look at some of the analysis coming out of the business sector. Fostering productive teams, after all, is critical to the success or failure of many modern businesses.

One finding from the business realm that will make immediate sense to educators is that creating a context that fosters shared identity promotes productivity. You can read more about this research in “Spaces the Signal Identity Improve Workplace Productivity,” in the Journal of Personnel Psychology. We know that giving our students a sense of belonging and recognizing who they are and what they bring is critical to fostering a positive school community. But it’s good to know that it also can improve group performance.

Another finding is that how a team communicates is what determines its effectiveness. As presented in an article, “The New Science of Building Great Teams” in Harvard Business Review, effective teams communicate more equitably and with higher engagement. And even more critically for consideration in a school context, socialization outside of formal meeting time has a huge influence on team effectiveness. What this means for educators is that fostering effective group work requires time and training. Furthermore, as described in a passage “Group Dynamics for Teams” by Daniel Levi, this training requires norming, socialization, and building cooperative skills. Educators know that many of our students struggle with social skills and working productively together. These skills must be taught and developed.

Similarly, moving into research from higher education, in “What makes a ‘good group’? Exploring the characteristics and performance of undergraduate student groups” the authors argue that if “team working skills” are “important as a learning outcome, they must be assessed directly alongside the task output.” In other words, if a teacher is going to utilize group work for a task, they must establish explicit learning objectives for the skills practiced in the group work itself, not only for the content of the task. This again reinforces the idea that when we do use group work, we must do so strategically.

This builds off of Robert Slavin’s review of educational research, as outlined in an ACSD article, “Cooperative Learning and Student Achievement,” which suggests that not only must effective group work have group goals and rewards, but also must hold each individual accountable for their contribution. Group work which incorporates only one aspect of those two critical components (group goals and individual accountability) demonstrates little benefit to learning, whereas group learning which incorporates both is far more effective.

Even adult research teams require training and practice to develop intrapersonal awareness, foster shared norms, and to understand that conflict is normal, as suggested by a paper “Creating and maintaining high-performing collaborative research teams: the importance of diversity and interpersonal skills.” The authors further suggest that fostering diverse teams is essential to productivity.

This latter insight, that diverse teams are more productive, may be one of the most useful within a classroom context. Various studies, as presented in an article on Harvard Business Review, “Why Diverse Teams Are Smarter” by David Rock and Heidi Grant, suggest that ethnic and racial diversity makes for more effective, deliberative, and innovative teams. This is an important consideration for teachers when forming groups.

A recent study by P. Karen Murphy et al., “Exploring the influence of homogeneous versus heterogeneous grouping on students’ text-based discussions and comprehension” provides useful guidance for teachers in deciding between homogenous vs. heterogenous grouping:

“. . . teachers’ goals and expectations for small-group discussions should guide their decision to compose the groups homogeneously or heterogeneously. For example, if teachers desire to focus on enhancing students’ basic comprehension or if they desire to support students’ engagement in the discussion, they may find that grouping the students homogeneously is more advantageous for low-ability students. Alternatively, teachers should employ heterogeneous ability grouping if their focus is on building students’ high-level comprehension of the text.”

In other words, group homogeneously to engage low-skilled students; group heterogeneously to deepen comprehension.

However, it’s important to note that research on homogeneous vs. heterogeneous grouping is mostly unclear. Ultimately, how a teacher chooses to group students must be strategic and based on the task and learning outcomes. But overall findings seem to suggest that our default should be mixing students of different backgrounds and ability.

A synthesis of findings on effective group work

Ok, so we’ve reviewed a fair amount of information on grouping. Let’s summarize what we have so far:


  • Use group work only when it is necessary to achieve the task you are planning
  • When assigning group work, ensure that the task is complex enough to warrant collaborative effort.
  • Create a classroom and school environment that fosters a shared identity
  • Provide norming, time for socialization, and training in the cooperative skills students will require to work productively as a team
  • Set explicit learning targets for group work skills when engaging in a group task, while holding each individual student accountable for their work within the group
  • Group students heterogeneously to promote greater critical thinking and creativity



Bennett, T. (2015). Group Work for the Good. American Educator. Retrieved from http://www.aft.org/ae/spring2015/bennett

Channon, S.B. (2017). What makes a ‘good group’? Exploring the characteristics and performance of undergraduate student groups. SpringerLink. Retrieved from https://link.springer.com/article/10.1007/s10459-016-9680-y

Cheruvelil, K. S., Soranno, P. A., Weathers, K. C., Hanson, P. C., Goring, S. J., Filstrup, C. T. and Read, E. K. (2014), Creating and maintaining high-performing collaborative research teams: the importance of diversity and interpersonal skills. Frontiers in Ecology and the Environment. 12: 31–38. doi:10.1890/130001. Retrieved from http://onlinelibrary.wiley.com/doi/10.1890/130001/abstract

Greenaway, K.H., Hannibal A. Thai, S. Haslam, A., and Murphy, S.C. (2016). Spaces That Signal Identity Improve Workplace Productivity. Journal of Personnel Psychology. 15(1), 35–43. Retrieved from https://www.researchgate.net/publication/301277968_Spaces_That_Signal_Identity_Improve_Workplace_Productivity

Fisher, D. & Frey, N. (2010). Scaffolds for Learning: The Key to Guided Instruction. ASCD. Retrieved from http://www.ascd.org/publications/books/111017/chapters/Scaffolds-for-Learning@-The-Key-to-Guided-Instruction.aspx

Kirschner, P.A., Sweller, J., Kirschner, F., and Zambrano, J. (2018). From Cognitive Load Theory to Collaborative Cognitive Load Theory. International Journal of Computer-Supported Collaborative Learning. Retrieved from https://link.springer.com/article/10.1007%2Fs11412-018-9277-y

Levi, D. (2001). Group Dynamics for Teams. Sage Publications, 322 pp. Retrieved from http://citeseerx.ist.psu.edu/viewdoc/download?doi=

Murphy, P.K., Greene, J.A., Firetto, C.M., Li, M., Lobczowski, N.G., Duke, R.F., Wei, L., Croninger, R.M.V. (2017). Exploring the influence of homogeneous versus heterogeneous grouping on students’ text-based discussions and comprehension. Contemporary Educational Psychology. 51, 336-355 Retrieved from: http://www.sciencedirect.com/science/article/pii/S0361476X17302540

Pentland, A.S. (2012). The New Science of Building Great Teams. Harvard Business Review. Retrieved from https://hbr.org/2012/04/the-new-science-of-building-great-teams

Rock, D. and Grant, H. (2016.). Why Diverse Teams Are Smarter. Harvard Business Review. Retrieved from https://hbr.org/2016/11/why-diverse-teams-are-smarter

Slavin, R. (1988). Cooperative Learning and Student Achievement. ASCD. Retrieved from http://www.ascd.org/ASCD/pdf/journals/ed_lead/el_198810_slavin.pdf

Wang, Z. (2013). Effects of heterogenous and homogenous grouping on student learning. Chapel Hill. Retrieved from https://cdr.lib.unc.edu/indexablecontent/uuid:ac391807-1cca-447e-801d-d65183945ad0

Yee, V. (2013.). Grouping Students by Ability Regains Favor With Educators. NY Times. Retrieved from https://www.nytimes.com/2013/06/10/education/grouping-students-by-ability-regains-favor-with-educators.html

Group Work Decision Tree

Copy of Group Work Decision Tree - Page 1

Student Grouping: What is Effective? by Mark Anderson is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

A Revision on Group Work: Assign complex—rather than simple—tasks


Paul Kirschner, John Sweller, Femke Kirschner, and Jimmy Zambrano published a recent paper in the International Journal of Computer-Supported Collaborative Learning titled, “From Cognitive Load Theory to Collaborative Cognitive Load Theory,” in which they make the case that cognitive load theory needs to be reconsidered from a different frame for group tasks.

I found it interesting because I had created a synthesis on group learning a while back (read all about it here), and much of Kirschner et al.’s synthesis aligns with much of what I found, such as that group work requires the development of collaborative skills, the importance of clear, accountable roles and expectations for group tasks, or that heterogenous grouping should be our default when creating groups.

However, there was one key piece that seemed to contradict a finding I had drawn from Doug Fisher and Nancy Frey’s book, “Guided Instruction,” which is that new concepts and information should not be introduced during group work, as this would overload students’ working memory.

Kirschner et al. instead suggest that working as a group creates a collective working memory, and that therefore group tasks should be more complex. They state, “… learning in a team is more effective than individual learning if the complexity of the to-be-learned material is so high that it exceeds the limits of each individual learner’s working memory.” They furthermore suggest that greater complexity will make the task more engaging for the group: “Collaboration will occur when the task is complex enough to justify the extra time and effort involved in collaborating with others.”

However, they also caution that “In terms of cognitive load, if learners have not acquired [task-specific collaboration] skills prior to beginning on the collaborative task, the load induced here could be so high as to hinder collaborative learning.” This agrees with what I also found in my synthesis, which is that fostering effective group work requires time and training, with explicit learning objectives for the skills practiced in group specific tasks. As Kirschner et al. puts it, “We may need to be taught how to communicate and coordinate carrying out complex tasks in order to optimize transactive activities and construct better knowledge and skill schemas (Zambrano et al. 2018).”

Kirschner et al. also highlight the different considerations we need to make for students based on what they already know. In fact, they seem to suggest that students with low levels of domain-specific knowledge can benefit the most from engaging in group tasks, whereas students with higher level of expertise may have their learning hindered by the additional elements introduced by collaboration. Here’s two relevant quotes on this:

“When teams are composed of learners with a low level of domain-specific knowledge, these novices need to be involved in cognitively demanding search-based problem solving, whereas when they are knowledgeable, this is not the case as the learners can probably deal with the problems using their available knowledge base. Also, when teams are composed of learners with a low level of domain-specific knowledge, there is a greater potential for a larger increase in collective WM than when individuals have high levels of domain-specific knowledge required by the task.”

“With respect to cognitive load, if learners have relevant knowledge to carry out a task, communication and coordination activities may be unnecessary or even detrimental to learning. When there is little domain-specific knowledge, the cognitive load incurred by transactions could positively impact learning but where there is a great degree of expertise, and thus where transactions are either unnecessary for or detrimental to learning (Zambrano et al. 2017b), the cognitive load incurred could negatively impact learning.”

I’m glad I reviewed this article, as it has helped me to clarify my thinking about assigning group work.

To summarize the key point I’m revising my thinking about group work on:

Fromnew concepts and information should not be introduced during group work. Group work should be used for reinforcing, consolidating, and applying information students have already been exposed to


When assigning group work, ensure that the task is complex enough to warrant collaborative effort.

I’ll provide an updated decision-tree and guiding document to reflect this learning soon.

The Symbiosis Between Scaffolding and Differentiation

A while back I wrote a long post redefining scaffolds and examining their connection to success criteria.

I then wrote a post drawing a distinction between scaffolds and differentiation, and I cast some shade on differentiation.

But I’m no longer quite as opposed to differentiation, and I can now see how there can be a strong symbiosis between scaffolding and differentiation.

I’ve been working with a school in the Bronx where we’ve been talking a lot about these concepts, and they’ve helped me to think a little more deeply. So I figured it would be worth sharing my updated learning.

Why it’s important

Teachers are often criticized by school and district leaders for not “differentiating” enough, yet rarely provided any clear guidance on how to do so. And there’s furthermore a lot of vagueness out there in the field on the distinctions between scaffolding and differentiation.

I want to share my revised thinking on the connection between the two concepts in the hope that I can help to clarify, rather than muddy, the use of these terms.

Here’s a visual model of how I now view scaffolds and differentiation:

Scaffolding = Steps

As students practice a skill or develop knowledge of a concept, their ability and understanding increases in complexity. A master teacher breaks down a skill or concept into smaller components, all the way down to the most basic and fundamental level, so that students can accelerate up the ladder towards mastery (just as jump school recruits do with a parachute landing fall).

Those sequential steps are the scaffolds.

Scaffolding, therefore, requires a teacher to be deeply knowledgeable of what is taught (content/skills).

Differentiation = Where each student is on those steps and what they need to progress

Differentiation, on the other hand, requires a teacher to know their individual students well enough to know what each student requires at every step on their trajectory towards mastery, and where they are on that trajectory.

Differentiation requires a teacher to be deeply aware of each of their individual student’s needs and current level of performance.

Distinguishing between Scaffolds and Differentiation

  • Scaffolding is aligned to a concept or skill.
  • Differentiation is aligned to the individual student.
  • Scaffolds are the sequential steps that lead to mastery of a skill or a deeper understanding of a concept.
  • Differentiation is in what manner and how much time a student may need to practice or review a step, as well as how much feedback may need to be provided.
  • Scaffolding requires a teacher to be deeply knowledgeable of what is taught.
  • Differentiation requires a teacher to be deeply aware of each individual student’s needs and current level of performance.

The two thus work in tandem.

A sidenote on how all this relates to personalized learning

This brings out something interesting about the edtech industry’s drive for “personalized learning.” The concept of personalized learning arguably aligns most strongly with differentiation.

What is not frequently discussed is that in order to personalize something, you must first define that “something” and break it into its component parts. How you do this and the decisions you make and the feedback you provide are just as important as matching that content to a student’s needs.

In other words, whenever you hear about personalized learning, ignore the inspirational student-centered rhetoric and home in on the content itself. What platform or curriculum is being used? What trajectory is presented by that content? Does this trajectory align with widely respected standards or guidance from national or international professional organizations.

Definitions and Characteristics



A scaffold provides opportunities for performance and practice of the component content and skills that a student requires to achieve success in a unit of study.


  • Smaller, sequential components of a complex concept, task, or skill
  • Requires a teacher to be deeply knowledgeable of what is taught
  • At the right level of “desirable difficulty” for practice; in other words, a scaffold isn’t about making something “easier” for students
  • Must be mastered at each step along the way. Students shouldn’t move along or have a scaffold removed until they have demonstrated mastery of each component
  • Doubles as performance-based formative assessment



Differentiation provides an individual student with the targeted practice or thinking, and with the necessary feedback, in order to progress towards defined learning goals.


  • Adjustments in environment, content, process, or product to account for an individual student’s current level of knowledge, ability, or interest
  • Based on the trajectory of scaffolding for the current topic or unit of study
  • Requires the teacher to be deeply aware of an individual student’s needs and current level of performance
  • At the right level of “desirable difficulty” for practice; in other words, differentiation isn’t about making something “easier” for the student

You’ll notice that there is a key characteristic that is shared between these two: neither are about making something easier for a student — they are both about moving learners closer to mastery of whatever it is that they are practicing and studying.

This is important because unfortunately there is a strong tendency by educators to deem some students as incapable of achieving mastery of success in academic learning.

But what is most often the case is that the educator doesn’t know what they are teaching well enough in order to provide specific and targeted supports for their students.

There’s still a lot more to dig into on this topic — specifically how it relates to formal education plans (IEPs) for students with disabilities. But I think this is more than enough for one post!

Please push back on any of this to help me further clarify and refine my thinking on scaffolding and differentiation.

Scaffolding vs Differentiation

My recent post on scaffolds and success criteria seemed to be useful to folks, so I thought I should share something more on scaffolding that can help to further clarify the term.

Scaffolding and differentiation are both words frequently thrown around in schools, often interchangeably and without precision. But there’s a clear distinction between the two that must be made, most especially as teachers are increasingly pressured to “differentiate” their lessons by school and district leadership with little guidance and concrete models.

So what is differentiation?

Differentiation asks teachers to plan different tasks or learning experiences for different groups of students, with the idea being that we can better meet the needs of diverse learners.

So for example, if we had our “high” student, our “medium” student, and our “low” performing student, we might provide a different text for each one in order to ensure they would be reading something at their “level.”

But there’s a problem with this. If the so-called “low” students only ever receive less complex and challenging expectations, texts, and learning experiences, they will continue to perform at a lower level.

This is why too many of our kids end up in “remedial” classes if and when they make it to college. This is why too many students consigned to a segregated “self-contained” program rarely even make it to graduation.

There’s another problem with differentiation. It demands quite a bit from a teacher to design (at least) 3 separate tasks or resources for any given lesson — time and energy that could perhaps be more effectively spent elsewhere.

To acknowledge these problems is not to say that differentiation can’t be applied effectively nor that it is universally the wrong thing to do. Structures for guided reading, for example, draw from this model and can be very effective in a school and classroom that have developed the necessary systems and routines. But these problems are big enough that they should give us strong pause before mindlessly evaluating and chiding teachers about whether they are adequately “differentiating” their lessons.

What is scaffolding, and how is it different?

The concept of scaffolding shifts how we approach meeting the needs of diverse learners.

We may have students coming into a learning experience with differing levels of knowledge, ability, or background, but rather than providing them with something different, we instead consider how we can provide the scaffolding necessary to ensure they can work together in grappling with a common task or text.

This is a shift offered by common standards, which demand a shared set of expectations for all students. For our students who may struggle in meeting these more rigorous demands, we must consider how to scaffold the concepts, procedures, and environment to support their engagement in practice with the texts and learning experiences that can enable them to meet those expectations.

This is certainly not an easy thing to do, either. But if I had to take a pick about what is going to give me the most bang for my buck, designing access and practice with common vocabulary, tasks, and texts is where I would ask educators to more wisely invest their time and energy.

For more on what that scaffolding should look like, take a look at my prior post, Scaffolding and Success Criteria.

Smorgasbord: August looms

A chart from one of my recent sessions

Teacher evaluation is about relationships and learning, not about scores

Long ago, I co-wrote a policy paper advocating for a teacher evaluation system that acknowledges that evaluation is a conversation that requires the context of a professional learning community, with input not only from the administration, but furthermore one’s peers.

While a pre and post-conference is included in most current eval systems, the reality is that the focus is on 1) compliance (paperwork), 2) the stakes/consequences attached to that paperwork, and 3) the demands of a very subjective rubric, rather than on the practices and content that will move learning forward for students.

So it should come as no surprise that few teachers are rated poorly by their principals. These systems have become all about summative evaluation, rather than formative feedback, and thus have lost sight of the real purpose of the system in the first place — to improve teacher practice and student learning. Effective principals will use the system to have those conversations — but they won’t rate their teachers poorly on paper unless they are intent on pushing them out the building.

Principals Are Loath to Give Teachers Bad Ratings, Ed Week

Research shows: Elect Democrats to fight segregated schools

Partisan tensions between individualism/choice and systems/regulation in action.

Want to reduce racial segregation? Elect a Democrat to school board, study says, Chalkbeat NY

Andy Rotherham argues against safe spaces

“. . . challenging people to become bigger than themselves is at its core an act of respect and love. Shielding them from challenge, especially in their most formative years, is fundamentally deeply disrespectful to them and their education.”

He’s talking about higher ed. But this also applies–arguably, even more importantly–in K-12.

Challenge Students, Don’t Shield Them,” US News

John King and Arne Duncan plead for sanity in regulations to protect students

“Protecting students and taxpayers shouldn’t be a partisan political issue.”

It shouldn’t. Unfortunately, however–in our country, in these times–it is.

Trump administration is putting profits over students, The Hill

The Problem with Robot Teachers

“I . . . worry that we’re slowly evolving toward a system where the affluent get that kind of education and the poor get automated schooling.”

Are The Robots Coming? Is The K-12 Sector Allergic To Accountability? Cheating In DC, College Access, David Harris Goes TEDx, Claudio Sanchez On ESSA, Jeff Walker On Systems Entrepreneurs, Curbing Eliteness, Cow Horse, More!, Eduwonk

A middle school in the South Bronx harnesses the power of testing & practice

This Bronx school is applying what we know from decades of research: repeated quizzing and practice of key skills and concepts, spaced out over time, transfers learning into long-term memory.

Kudos to MS 343. When you think about just how much of an outlier this approach is, it’s pretty disturbing. Most schools do not have a coherent and systematic approach to what they teach, nor consider how they are reinforcing what is most essential to learn across grades and classrooms.

Why this Bronx middle school believes in second — and third — chances, Chalkbeat NY

Speaking of practice, here’s 10 teaching techniques worth practicing

This is a useful list of a few pedagogical methods worth spending time mastering from UK educator Tom Sherrington, which are based on Deans for Impact’s advice for deliberate practice.

Ten teaching techniques to practise – deliberately., Teacherhead.com

NYCDOE is pressing ATRs into schools

Dan Weisberg writes an op-ed in The 74 against the move, claiming that “Principals would go back to hiding vacancies and would justifiably argue that they can’t be held accountable for student learning if they don’t get to pick their teams.”

His claim appears to be justified, as a recent Chalkbeat article reports:

“I’m going to make sure my school doesn’t have a vacancy,” said one Bronx principal who wished to remain anonymous due to the sensitive nature of the topic. “I’m not going to post a vacancy if someone will place an ATR there. I’ll be as strategic as I can and figure out another way.”

I think Weisberg’s suggestion makes much more sense: set a time limit on how long someone can be in the ATR pool.

Weisberg: Paying Teachers Not to Teach Is Absurd — but Reviving NYC’s ‘Dance of the Lemons’ Hurts Kids, The 74

New York City principals balk at plan to place teachers in their schools; some vow to get around it, Chalkbeat NY

Randi Weingarten calls Devos’s brand of choice what it is — but what is her union doing to fight segregation?

I think Weingarten is pointing out an inconvenient truth by calling vouchers a “polite form of segregation,” given their history and the folks that most typically foam at the mouth over them.

But I do wonder what exactly she and her union are doing to fight segregated schools. Public schools are doing plenty on their own to contribute to segregation without any consideration of charters nor vouchers.