State and national standards demand that all students master grade-level learning standards; yet some learners who already know those skills and concepts may be treadmilling instead of learning. Tiered instruction invites educators to rethink traditional educational practices based upon a prior time when students were more similar in background and readiness.

• Tiered instruction blends assessment and instruction. Before initiating each segment of learning, the teacher completes a preassessment to determine what students know and then prescribes content materials and learning experiences that promote continued learning for each student. As teachers consider students' assessed readiness levels, it becomes obvious that everyone is not at the same place in their learning and that different tiered tasks are needed to optimize every student's classroom experience.
• Tiered instruction aligns complexity to the readiness levels and learning needs of students. The teacher plans different kinds and degrees of instructional support and structure, depending upon each student's level. Tiered instruction allows all students to focus on essential concepts and skills yet still be challenged at the different levels on which they are individually capable of working.

Ideally, tiered learning tasks engage students slightly beyond what they find easy or comfortable in order to provide genuine challenge and to promote their continued learning (Sylwester, 2003; Vygotsky, 1986). Optimally, a tiered task is neither too simple so that it leads to boredom nor too difficult so that it results in frustration. As Tomlinson cautions, "Only when students work at appropriate challenge levels do they develop the essential habits of persistence, curiosity, and willingness to take intellectual risks" (2001, 5).

Tiered instruction is like a stairwell providing access within the large building called learning. The bottom story represents learning tasks for students with less readiness and fewer skills. The stairwell continues through enough levels to reach the appropriate challenge for advanced readiness students with very high skills and complex understanding. There isn't always a student working on every stairwell level as students progress through tiers of learning at different paces. Also, within each tier, there simultaneously can be multiple small-group activities presenting different ways to learn. Some floors in the stairwell even have multiple stairways as students access higher learning levels differently.

1. Ensure that group membership is flexible.
The word tiered is not a euphemism for stagnant low-middle-high groups that label who can learn and who is not learning. Tiered assignments denote all children as able to learn the same essential skills in different ways. The make-up of students working at each tier varies with the content, assignment, and quantity of tiers.

2. Plan the number of levels most appropriate for instruction.
Different quantities of tiers are needed for different curricula areas, concepts, and skills in relation to different learners' needs. Sometimes, two tiers are sufficient; at other times, three to five or more work better to match the wide range of learners. Changing the number of tiers is also a way to vitalize flexible groupings and ensure that students are not always in the same group.

3. Recognize that complexity is relative.
The complexity of a tiered assignment is relative because it is determined by the specific needs of the students and because learners' readiness levels vary in different curricula areas. In classes with below grade-level learners, the lowest tier would respond to those students. In classes in which all students are at or above grade level, the lowest tier would respond to grade-level or even above grade-level readiness.

4. Promote high-level thinking in each tier.
The background and readiness levels of students should not limit the range of thinking opportunities provided through tiered assignments. Avoid always allocating simple thinking tasks for students with the fewest skills. All students need opportunities to analyze, synthesize, and evaluate information.

5. Provide teacher support at every tier.
Every tier requires teacher modeling and support for the students working at that tier. All learners benefit from a teacher's instruction, interaction, guidance, and feedback--even gifted children whom some educators perceive as always making it on their own.

Complete the Quiz in Figure 1. Then, analyze your problem-solving on the quiz to conclude which factors influence tiering complexity.

Figure 1 A Quiz: Tiered Reading Tasks Number each task tier 1, 2, 3 or 4 as you determine the simplest (1) to most complex (4) learning tasks. A. Students work in trios to create a Venn Diagram comparing the traits of the main characters in the two novels they read. With the teacher, the trios then compare their diagrams and identify how those traits caused similar effects in the sequence of both stories . B. With the teacher, students determine the five key events in sequence in the story that affected the main character. They then discuss and record the cause of each. ____Effect__________________________Cause___________________ 1. 2. C. The teacher discusses and lists five key events in the story that affected the main character. With the teacher, students determine the sequence of those events and then record the cause of each. ____Effect: What happened?____________Cause: Why?_____________ 1. 2. D. With teacher facilitation, students use a Venn Diagram to compare traits of the main character at the beginning and end of the book. Then, they brainstorm, list together, and sequence the events that caused the character to change.

Reflect upon your problem-solving process on the quiz. What are similarities among the tiers? For example, notice that all of the tasks incorporate essential concepts and skills including high-level thinking, character analysis, cause and effect relationships, and sequence.

What are some of the differences among the levels? For example, which aspects of tier one make it more simple than tier three? Differences, such as the ones you identify, are the factors that influence the complexity of tiered tasks. Analyses of a myriad of tiered tasks by other teachers resulted in the list of factors in Figure 2.

Degree of assistance and support
Teacher directs instruction
Teacher facilitates
Small group support
Individual autonomy

Degree of structure
Clearly defined parameters
Open-ended criteria and parameters

Required background knowledge and skills
Minimal, basic information
Grade-level information
More extensive information and understanding is required

Concrete or more abstract
Process and product are concrete
Process and product involve abstract thinking and interpretation

Quantity of resources
Single resource is provided
Multiple and varied resources are employed

Complexity of resources
Grade-level resources
Resources require above grade-level ability
Resources are concept dense
Sophisticated technology applications are required

Complexity of process
Pacing
--Repetition and guided practice are paced at rate typical for grade level
--Minimum repetition and practice allow acceleration
Number and complexity of steps
--Process is simple and short-term
--Multiple steps and an extended period of time are required
Simple to high-levels of thinking
Sophisticated research skills are required

Complexity of product
Simple, correct answers
Varied and complex responses
Integration of advanced skills and concepts is required

Identifying complexity factors helps teachers efficiently proceed with the development of tiered tasks. When you assess that students require variations of the concepts and skills designated in a lesson, reflect upon these factors as a checklist. Select one factor or combinations of the factors to appropriately vary instructional complexity. Some of the factors are more easily modified by the teacher, such as the degree of assistance a teacher provides, the complexity of the resources used, and the concrete or abstract nature of the process and product. Some factors are non-negotiable and require teachers to understand and accommodate within every tier, such as the background knowledge and skills students bring to the task.

Tiered instruction evolves from teachers' assessments and decisions regarding how to modulate tasks around the combinations of factors they select that influence complexity. The intent is to accommodate the unique diversity of learners rather than to divide students into leveled groups.

Begin or extend your tiered instruction by varying one lesson. Then, reflect upon that success and consider tiering another learning experience.

Kingore, B. (2004). Tiered Instruction in Differentiation: Simplified, realistic and effective. Austin: Professional Associates Publishing.

Sylwester, R. (2003). A Biological brain in a cultural classroom. Thousand Oaks, CA: Corwin Press.

Tomlinson, C. (2001). Differentiated instruction in the regular classroom: What does it mean? How does it look? Understanding Our Gifted, 14, 3-6.

Vygotsky, L. (1986). Thought and language. Cambridge: MIT Press.