One of the most comprehensive models of DI to date was provided by Tomlinson, a leading expert in the field (see Tomlinson, 1999, 2014; Tomlinson & Allan, 2000; Tomlinson & Imbeau, 2023; Tomlinson & McTighe, 2006; Tomlinson & Moon, 2013). The model has two main dimensions: the curriculum areas to be differentiated and the learner differences along which differentiation is applied. In terms of the first one, Tomlinson specifies the content (the information, attitudes and skills students need to grasp and be able to use), the process (how students take in the content), the product (how students show what they have learned) and the learning environment (the affective climate of the classroom). In terms of the second aspect, she identifies students’ readiness (proximity to specified learning goals), interests (passions and affinities that motivate learning), and learning profiles (preferred approaches to learning) (Tomlinson, 1999; 2014; Tomlinson & Allan, 2000; Tomlinson & Imbeau, 2023).

 

2.1.3.1 The What Aspect of DI: Content, Process, Product and Learning Environment. According to Tomlinson and Imbeau (2023), at the core of DI are four curriculum-related elements that can be adjusted: the content, the process, the product and the learning environment, more recently referred to as affect. Content refers to the knowledge, understanding, and skills students are expected to learn. As emphasised by Tomlinson and Allan (2000), content typically remains consistent for all learners in a differentiated classroom. However, in exceptional cases where differences are substantial and justified, variations in the content itself may occur. One example the authors mention is giving varying spelling lists to students when some of them spell at a 2nd grade level while others are already at an 8th grade level. Nevertheless, what is more likely to vary in terms of content differentiation is how students gain access to core learning. This can be done, for example, through tiering, i.e., by allowing students to engage with the material “at different levels of difficulty based on their current proficiency with the ideas and skills” (Tomlinson & McTighe, 2006, p. 107). Further strategies include the presentation of information through both whole-to-part and part-to-whole approaches, and scaffolding, i.e., providing additional support or challenges (for example, by setting up reading buddy arrangements, reteaching students, or using multimedia tools as a way of conveying key concepts) (Tomlinson & Allan, 2000).

2.1.3.2 The How Aspect of DI: Learners’ Readiness Levels, Interests, and Learning Profiles. In Tomlinson’s (1999, 2014) model, the content, process, product and learning environment may be differentiated along three types of learner differences: interests, learning profiles, and readiness levels. Interest refers to the affinities that drive students, i.e., all the things that engage “the attention, curiosity and involvement of a student” (Tomlinson & Imbeau, 2023, p. 33). Learning profile is an umbrella term that encompasses dimensions such as learning styles (i.e., a preferred contextual approach to learning, such as working alone or with a partner, in a quiet place or with music playing, etc.), Gardner’s (1983) intelligence preferences (i.e., visual-spatial, verbal-linguistic, musical, logical-mathematical, interpersonal, intrapersonal, naturalistic and bodily-kinaesthetic), gender, and cultural background.

2.1.3.3 The Guiding Principles of DI. There are multiple principles that guide the implementation of DI, such as respectful tasks, ongoing, formative assessment, flexible grouping, and student choice (Tomlinson, 1999; 2014; Tomlinson & Allan, 2000; Tomlinson & Imbeau, 2023). In what follows, I briefly discuss these principles.

 

2.1.3.4 A Brief Overview of Differentiation Strategies. The list of DI strategies available for teachers is extremely rich. While it is not the aim of the present literature review to provide a detailed analysis of each of these, a discussion of some strategies frequently presented in guidebooks for DI in TEFL (e.g., Blaz, 2018; Theisen, 2002) are provided. While using the Tomlinsonian (1999) vocabulary of differentiation to frame their discussion, these resources provide subject-specific ideas relevant to the teaching of foreign languages.

 

2.1.3.4.1 Choice Boards. This strategy offers a list of choices for students. As Blaz (2016) explains, the activities can be arranged by types of activities (i.e., oral, written, listening), by subject (grammar, vocabulary), by skill level (from easy to more challenging), by time frames or by learning styles or multiple intelligences. Two typical formats of choice boards are menus and Tic-Tac-Toe grids. In the former, the activities are listed as a form of menu, labelled as appetisers, soups, main courses, and desserts, and students pick one activity from each category. In the latter, the activities are arranged in a tic-tac-toe grid, and students choose three activities that form a Tic-Tac-Toe, either horizontally, vertically, or diagonally. If there is an activity that the teacher insists every student should do, they can put it in the centre and tell students the Tic-Tac-Toe needs to include the centre (Blaz, 2016).

 

2.1.3.4.2 Learning Centres. In this strategy, activities are placed at different ‘stations’ in the classroom, and students move on to each station at their own pace. Each centre would ask students to engage with the material of a given unit in a different way, e.g., through reading, writing, listening, speaking, or drawing. Students may be free to decide which centres to visit, or they can be assigned to certain centres based on their needs, with the option to visit other centres after completing the compulsory tasks (Theisen, 2002).

 

2.1.3.4.3 RAFT Assignments. RAFT (Role, Audience, Format, Topic) assignments offer students various instructions that encourage critical thinking and the development of writing skills, all centred around the same concepts and skills in a lesson or unit. These assignments invite students to take on different roles and express themselves through different written formats. The Role involves assuming a specific character or viewpoint, the Audience determines who the message is intended for, the Format defines the method of communication, and the Topic focuses on a central idea. Blaz (2016) provides an example of how the topic of food may be explored in the foreign language classroom using a RAFT strategy: students can practise vocabulary and develop their writing skills by creating written products in different roles (e.g., cookbook writer, chef, travel writer) for various audiences (e.g., cooks, customer, reader wanting to travel), employing different formats (e.g., recipe, menu, recommendation), and focusing on different topics (e.g., instructions on food preparation, detailed description of food preparation, good things to eat while visiting and what to avoid). The principle of choice is present in this strategy, as well, i.e., students can decide which task to work on and then accomplish it with the help of a checklist prepared for that specific task.

 

2.1.3.4.4 Projects. Projects, or project-based learning (PBL) is defined by Blaz (2016) as “a teaching method in which students work for an extended period of time to investigate and respond to a complex question, problem, or challenge of their own choice” requiring research and culminating in a presentation of the project (p. 183). What makes PBL especially suitable for DI is its inherently student-centred nature, as it allows students to choose topics of interest and engage in active problem-solving, research, and collaboration, all of which closely correspond with the principles of DI (Tomlinson, 2017). The way they research the problem (process) and how they demonstrate their learning (product) is also, to an extent, left to the students’ discretion, which further caters for their individual needs and preferences.

2.1.3.5 Concluding Notes on Tomlinson’s Model of DI. It is important to note that while there are several studies supporting the effectiveness of differentiation along one of the dimensions of Tomlinson’s (1999, 2014) model (for an overview of studies conducted in the context of TEFL, refer to Section 2.1.5.2), the implementation of the model as a whole has scarcely been investigated (Erickson, 2010). Tomlinson (Tomlinson et al., 2003; Tomlinson & Allan, 2000) herself acknowledges that additional research is necessary to gain insight into the complexities of DI.