Specifically, instruction should occur between the
lower threshold of development and the upper threshold represented by the problems
the child can complete with assistance (Vygotsky, 1934/1987). According to
Tomlinson and Allan (2000) and Tomlinson (2010), ZPD supports DI because it
highlights the importance of the role of the teacher pushing the child into the
ZPD, coaching for success so the learner can manage alone, and promoting
independent thinking. The teacher is responsible for each student’s ZPD
(Tomlinson, 2006) by means of an instructional strategy called scaffolding in
which the teacher develops tasks to build on prior knowledge.


Differentiated Classroom

Tomlinson (2001, 2006) contended that a differentiated
classroom is proactive and student centered. A DI classroom promotes
challenging activities, and struggling students normally get extra support to
help them develop skills that enable them to do tasks independently. Typically,
differentiated classroom instruction addresses comprehension of concepts
instead of the material covered. Different grouping styles are paramount, and
formative assessments of student readiness and comprehension level are part of
the curriculum. Teachers regard themselves as facilitators and students as explorers.
Students set goals and assessments for themselves, based on their own level of development
(Van Sciver, 2005). The teacher plans positive hands-on instruction that enables
learners to become interested and engaged in the lesson. Children are the
center of all decision making in the classroom. Tomlinson (2004a, 2009)
observed that a differentiated classroom blends different types of group
instruction and is organic. Sometimes it is more effective to have small group instruction,
individual instruction, or whole-class instruction, depending on the task. For
instance, a lesson could begin as a whole-group lesson, break down into small groups,
or individuals could work alone. In this way, classroom diversity is an asset
as it allows for the contribution of multiple perspectives, multiple ideas, and
different ways to find solutions to problems.

The key characteristics of DI identified by
Tomlinson (1995) include the following: “(a) plan with hands-on activities; (b)
value learning; (c) built on evaluation; (d) use assorted methods to deliver
the lesson; and (e) vary instruction” (p. 5). The instructor’s duty in a DI
classroom is to offer rigorous instruction and challenging activities that
focus on significant learning. The teacher must know what is important in the
subject matter and be knowledgeable and creative when dealing with differences
in students. In addition, the teacher must adjust the presentation of the
lesson to relate to the students’ readiness levels and interests. Rubrics
displayed and group work are the focus of learning rather than the teacher’s
lectures. Formative assessments record the progress of the students along with
the goals and the assignments (Tomlinson, 2005).

Chang (1996) and Rock
et al. (2008) identified several methods of DI: (a)

on activities, (b) cooperative group, and (c) technology. As Rock et al.
explained, the particular importance of integrating technology into learning
“is a way to differentiate instruction for a child’s learning situations, and
the combination of technology makes it meaningful and creative for students in
an active learning environment” (as cited in Chang, 1996, p. 39). Unlike the
traditional educational setting, in DI, the students and teacher are collaborators
in the learning process. Some characteristics of DI are more student-focused than
others. Learners decide how they want to learn. Students have the opportunity
to select topics to study in depth and engage actively in their own learning.
Students learn best when they make connections between the curriculum and their
interests or life experiences (Landrum & McDuffie, 2010; Levine, 2003;
McAdamis, 2001; Tomlinson,2004b). In differentiated classrooms, children are
engaged in an environment in which they perform the same activities as children
in a non- differentiated classroom. However, in differentiated classrooms,
students have options guided by their interests and readiness for a particular
task (Tobin & McInnes, 2007). Central to DI is the flexibility to draw on
different methods and techniques in order to acknowledge the needs of
individual learners and different learning situations. There is no single
correct way to apply DI. Educational researchers generally concur that applying
many methods for student engagement and success is the key to promoting student
achievement (Gregory & Hammerman, 2008). Research has revealed that teachers
who regularly use a range of teaching and organizational strategies throughout the
classroom are more likely to connect what needs to be learned with more
students who need to learn the content (Tomlinson, 2006). What is common to
most DI techniques, though, is the use of manipulative to offer children
real-life learning experiences. Meaningful activities foster true understanding
without useless memorization of facts and names (Gregory & Hammerman,

Within science education, lessons are differentiated
to permit students to discover areas of interest, expand research skills, and
obtain instruction on separate science and inquiry skills (Gregory &
Hammerman, 2008). Science students, it is argued, should have multiple and
varied opportunities to collect, sort, categorize, observe, use science tools and
instruments, and take notes to perform a task (Dodge, 2009; Gregory &
Hammerman,2008; Haurv, 2002). Hands-on activities help develop science process
skills and promote achievement of learning, which involves applying the knowledge
to everyday situations. A wide range of DI strategies is available for application
in the science classroom. Many of these strategies are effective as teachers
practice DI. These strategies draw on the key findings of relevant empirical
research regarding their use.


Instructional Strategies

A number of researchers have investigated teachers’
actual use of various DI strategies and techniques. For example, in a 1-year
study in a California school district, the classroom inclusion practices of
five teachers from two middle schools were examined (Carolan & Guinn,
2007). The teachers were observed and interviewed about their beliefs and
routines. In this example of DI, the factors found to be common to differentiated
classrooms were that the teachers (a) offered personalized scaffolding, (b)used
flexible groups, (c) designed classrooms in which differences existed, and (d)
had relevant expertise.



Teachers acknowledge the academic potential of
learners by applying tieredactivities. Tiered activities can work with any
concept teachers teach or reinforce. The benefit of this method is that the
whole class masters the same topic, but individuals choose activities on their
level with the teacher’s assistance (Brimijoin, 2005; Garnett, 2010; Willard-Holt,
2003). Tiering starts with a heterogeneous, whole-group lesson. Smaller groups
are formed based on interest. The unit is tiered through assignments, materials,
or assessments that reflect the student’s ability level (Levy, 2008). Teachers
tier assignments by making small adjustments to teaching content within the
same lesson in order to challenge students appropriately, according to their
level of ability. Forsten, Grant, and Hollas (2002) and Rock et al. (2008)
recommended that before starting to tier activities at the conclusion of the
lesson, the key ideas and skills all learners should understand must be
identified. Then teachers should choose reading materials matched to the
learners’ reading levels on the same topic.

Tiered activities focus on preparing students for
different levels of difficulty of a task within the same lesson topic
(King-Shaver, 2008; Kobelin, 2009; Tomlinson, 2001). This form of DI mainly
assigns tasks at the learner’s level and acknowledges student interest
(Tomlinson, 1999, 2009). These tasks comprise investigations that are suitable for
learners and take into account their prior knowledge (Tomlinson, 2001, 2008).
The modification of activities in this way aids in understanding of the concept
taught while ensuring that every student is challenged (King-Shaver, 2008;
Tomlinson, 1999; Tomlinson & Edison, 2003). Writing in content areas is beneficial
and can take the form of tiered assignments. For instance, in an earth science class,
learners operating below grade level may write about places using the latitude
lines as references, while students on grade level might write about places
without using latitude lines (Tomlinson &Edison, 2003).

A number of researchers have investigated the use of
tiered activities in the classroom. Tobin and McInnes (2008), for example,
investigated the DI strategies of two teachers in one school district. Both
teachers were experienced, imaginative teachers who went beyond the call of
duty for their students and were accommodating, especially to special needs
students. After reading a book, “Margot’s” students were offered choices about
how they would respond to text. Margot used tiered activities and created
methods to restrict below-grade-level readers to making responses, which
related closely to the text. Students completed individualized questions to
guide them in completing the assignments with the appropriate complexity level.
Margot provided clear scaffolding directions and monitored the students’
understanding of the products. Moreover, she facilitated their answers to many
choices, taking account of their appropriate levels (Tobin & McInnes,

 Studies have
contributed to an increased understanding of how tiered activities can apply
most effectively in the classroom, but have also revealed outstanding gaps in
understanding. For example, Brimijoin (2005) conducted a case study of a fifth grade
classroom in which the teacher developed assignments at various tiers to
challenge all students as well as a task for all students based on key learning
goals that met the range of learning needs for the entire class. Brimijoin
concluded that in using tiered assignments, varying journal prompts for each
tier helped to solicit student responses if the questions were adjusted to
students’ ability levels. Stager (2007) observed the productiveness of DI on
tiered activities in improving student learning using fractions. Students in
homogeneous groups received instruction, then completed activities on their
level in the groups. Every student made important gains, according to the test
results, but not all students mastered the concept. Stager concluded that more
study is necessary to understand how DI can assist mastery learning by all



In DI classrooms, learners need practice in engaging
mutually to learn in group situations. Flexible groups apply when assessments
identify a group of learners having comparable needs, interests, or preferences
(Heacox, 2003; van Garderen & Whittaker, 2006). This DI method grants
teachers the opportunity to match children by their readiness level (Tomlinson,
2004a, 2004b, 2010). In addition, it allows learners to interact with different
peers in different groups. In flexible grouping, the composition of groups
varies depending on the specific learning objective and activity. Teachers
assign students to groups based on certain characteristics to complete a lab or
tasks in which learners must collaborate to finish an assignment. Groups might
be organized, for example, by task, motivational level, interest, learning style,
ability level, or randomly (Gregory & Hammerman, 2008; Tomlinson, 2004a,
2004b, 2006). Typically, each member of a group has a role. For example, a
student who writes well might become the recorder, while a good speaker may
present the group results to the class (K. M. Anderson, 2007; Willard-Holt,
2003). Teachers who utilize flexible grouping use different organizational
methods for instruction. For example, a middle school physical science class
might illustrate and describe the movement of particles in solids, liquids, and
gases. In group work, the students may write a story depicting the movement of particles
in one of the states of matter. Castle, Deniz, Baker, and Tortora (2005) examined
the impact of flexible grouping on student learning over a 5-year period. Their
results demonstrated that the percentage of students maintaining mastery
increased from 10% to 57%. The teachers in the study credited the use of
flexible grouping on learning to (a) focused lessons related to learning needs,
(b) the ability to keep the students attentive, and (c) improved student confidence.
The conclusions supported the application of flexible grouping to increase student
learning without the harmful effects of ability grouping (Castle et al., 2005).