**3. External and internal differentiation: A terminological note**

Some of the most contested issues of education policy lie in the following questions: How should we organize education and how should we divide students between schools and classes? Some people believe that students should be grouped based on their abilities (or other characteristics such as interest or motivation) as soon as possible. According to others, such grouping at lower levels of education cannot be justified. English writing scholars usually refer to the sorting of students into separate schools and classes as *tracking.* Some other terms are also used for the same phenomenon (see below). Because a relatively big terminological chaos exists in this area, we will first attempt to clarify the basic English terms related to tracking.

The word **tracking** is probably the most usual term in relevant English scholarly literature. Table 1 outlines the definitions of tracking by some recent scholarly dictionaries as well as the key authorities in the field (Gamoran, Hallinan, Oakes, Slavin). The Table 1 makes it clear that the perspectives of most authors are relatively similar. One might extract the following from their definitions of tracking: "Tracking is the sorting of students into separately educated groups with different curricula and different education programs. Such sorting may occur at the level of the education system or individual classes".


Table 1. Definitions of tracking in English literature

dividing students within the same class. This is in line with our intuitive understanding of those terms: while *tracking* implies something rather long-term and binding (the student creates a certain track and begins to follow it), the term *grouping* implies something rather

Let us complete the terminological review by mentioning the term **branching**, which refers to dividing students between different *types of schools,* a common practice in especially Central European countries, like Germany, Austria or the Czech Republic (Brint, 1998: 2298; Walters, 2001). While the term is not used as frequently, it appears as a favorable complement to the above terms as it implies dividing students between different types of schools in the way educational tracks *branch9*. There are two main types of branches: "academic" branch, which as a rule provides general education and prepare for further education, and vocational education branch preparing students for certain occupations10. Even more concepts contribute to the terminological chaos. Similarly as American English distinguishes between ability grouping and tracking, British literature also operates with two concepts. While *streaming* corresponds to the American *tracking,* the term *setting* is

Other scholars use more general terms and distinguish between external and internal differentiation. For example, Greger (2004) defines **external differentiation** as the creation of homogenous student groups that are educated separately all day long and for all courses. He understands **internal differentiation** as the grouping of students for certain courses (e.g., language classes for beginner and advanced students; electives) or the grouping of students within a class (e.g., group learning, cooperative learning). Thus, internal differentiation also includes the cases when students form a heterogeneous body (class) and

Time and the permanence of grouping represent Greger's main criterion for drawing the line between external and internal differentiation. External differentiation occurs when ability grouping affects all or most courses (or most of the school day); internal differentiation takes place, as Greger suggests, when such grouping is less frequent (affecting a small part of the school day or some courses only). Thus, according to this

To sum it up, we can distinguish between three types of differentiation: at the educational system, school, and class levels (see Table 3). We recommend leaving to empirical investigation the question to what extent students are grouped based on their abilities and educational achievement, on one hand, and personal preferences, on the other hand. This is because those factors are sometimes quite difficult to disentangle. For example, when students appear to be grouped based on their academic achievement at first sight, their personal aspirations and interest in a certain type of education may play a key role. It should be emphasized that practice is always richer than theory. In reality, we often observe

9 Brint uses the term *early branching system* for the education systems of German-speaking countries. 10 The number of identifiable branches is different between education systems. Some systems distinguish between high, average and low tracks, while others between "selective" and "non-selective"

analogous to *ability grouping* (e.g., Hallam et al., 2003; Ireson & Hallam, 1999).

are only grouped for a certain (small) part of the school day or for certain courses.

definition, there is no clear boundary between external and internal differentiation.

8 Kerckhoff (2000: 468) uses a similar term, *career branches.* 

branches only (cf. Greger, 2004).

small-scale and short-term.

However, there is less consensus among the authors about the *criteria* governing grouping. Some see purported abilities and education achievement as the only criterion, while others think that even personal motivation or interest may serve as a criterion. These dual perspectives on the term perhaps arise out of the history of its use. Originally, tracking referred to the differentiation of curriculum in line with students' interests, educational plans and ambitions. It was only later that the term began to refer to the differentiation of curriculum in line with students' abilities (Watt, 2006).

**Ability grouping** is another frequently used term. The Table 2 contains some of its definitions. The table makes it clear that the terms tracking and ability grouping are, in many ways, used synonymously. Nevertheless, ability grouping appears as somewhat more specific. First, it deals explicitly with grouping students according to their abilities (whether purported or real), thus making the process somewhat involuntary (what students can matters, as opposed to what they want). Second, a few authors (e.g., Rosenthal, 2008) use the term ability grouping to refer to dividing students *within* one class and the term tracking for separate classes within and between schools.


Table 2. Definitions of ability grouping in English literature

As we mentioned above, most authors do not distinguish between the terms *tracking* and *ability grouping*, treating them as synonyms. Therefore, one must always find out what exactly any given author has in mind. We suggest that future authors define clearly which concept of differentiation they bear in mind. We generally recommend the term *tracking* for dividing students between different classes and schools and the term *ability grouping* for

However, there is less consensus among the authors about the *criteria* governing grouping. Some see purported abilities and education achievement as the only criterion, while others think that even personal motivation or interest may serve as a criterion. These dual perspectives on the term perhaps arise out of the history of its use. Originally, tracking referred to the differentiation of curriculum in line with students' interests, educational plans and ambitions. It was only later that the term began to refer to the differentiation of

**Ability grouping** is another frequently used term. The Table 2 contains some of its definitions. The table makes it clear that the terms tracking and ability grouping are, in many ways, used synonymously. Nevertheless, ability grouping appears as somewhat more specific. First, it deals explicitly with grouping students according to their abilities (whether purported or real), thus making the process somewhat involuntary (what students can matters, as opposed to what they want). Second, a few authors (e.g., Rosenthal, 2008) use the term ability grouping to refer to dividing students *within* one class and the term tracking for

Slavin (1990)

Gamoran (1992a)

Vergon (2008)

Rosenthal (2008)

Davidson (2009)

Robinson et al. (2005)

**Definition of ability grouping Source** 

Any school or classroom organization plan that is intended to

Ability grouping is a broad term used to describe a set of

Ability grouping refers to the organizing of elementary and secondary students into classrooms or courses for instruction

Ability grouping is the practice of teaching homogeneous groups of students, stratified by achievement or perceived ability. Among the various forms of ability grouping are within-class ability grouping, crossgrade grouping, and between-class ability

Ability grouping is the practice of making student groupings based on ability and achievement in an attempt to provide instruction

As we mentioned above, most authors do not distinguish between the terms *tracking* and *ability grouping*, treating them as synonyms. Therefore, one must always find out what exactly any given author has in mind. We suggest that future authors define clearly which concept of differentiation they bear in mind. We generally recommend the term *tracking* for dividing students between different classes and schools and the term *ability grouping* for

Table 2. Definitions of ability grouping in English literature

Divisions among students for particular subjects, such as special class assignments for math or within-class groups for reading.

educational practices that sort students for instructional purposes based on their perceived learning capacity, as measured by achievement tests, cognitive ability tests, past academic achievement (i.e., grade point average), and teacher

curriculum in line with students' abilities (Watt, 2006).

separate classes within and between schools.

according to actual or purported ability

grouping, also known as tracking.

specifically relevant to each group's needs.

recommendations.

reduce the heterogeneity of instructional groups.

dividing students within the same class. This is in line with our intuitive understanding of those terms: while *tracking* implies something rather long-term and binding (the student creates a certain track and begins to follow it), the term *grouping* implies something rather small-scale and short-term.

Let us complete the terminological review by mentioning the term **branching**, which refers to dividing students between different *types of schools,* a common practice in especially Central European countries, like Germany, Austria or the Czech Republic (Brint, 1998: 2298; Walters, 2001). While the term is not used as frequently, it appears as a favorable complement to the above terms as it implies dividing students between different types of schools in the way educational tracks *branch9*. There are two main types of branches: "academic" branch, which as a rule provides general education and prepare for further education, and vocational education branch preparing students for certain occupations10. Even more concepts contribute to the terminological chaos. Similarly as American English distinguishes between ability grouping and tracking, British literature also operates with two concepts. While *streaming* corresponds to the American *tracking,* the term *setting* is analogous to *ability grouping* (e.g., Hallam et al., 2003; Ireson & Hallam, 1999).

Other scholars use more general terms and distinguish between external and internal differentiation. For example, Greger (2004) defines **external differentiation** as the creation of homogenous student groups that are educated separately all day long and for all courses. He understands **internal differentiation** as the grouping of students for certain courses (e.g., language classes for beginner and advanced students; electives) or the grouping of students within a class (e.g., group learning, cooperative learning). Thus, internal differentiation also includes the cases when students form a heterogeneous body (class) and are only grouped for a certain (small) part of the school day or for certain courses.

Time and the permanence of grouping represent Greger's main criterion for drawing the line between external and internal differentiation. External differentiation occurs when ability grouping affects all or most courses (or most of the school day); internal differentiation takes place, as Greger suggests, when such grouping is less frequent (affecting a small part of the school day or some courses only). Thus, according to this definition, there is no clear boundary between external and internal differentiation.

To sum it up, we can distinguish between three types of differentiation: at the educational system, school, and class levels (see Table 3). We recommend leaving to empirical investigation the question to what extent students are grouped based on their abilities and educational achievement, on one hand, and personal preferences, on the other hand. This is because those factors are sometimes quite difficult to disentangle. For example, when students appear to be grouped based on their academic achievement at first sight, their personal aspirations and interest in a certain type of education may play a key role. It should be emphasized that practice is always richer than theory. In reality, we often observe

<sup>8</sup> Kerckhoff (2000: 468) uses a similar term, *career branches.* 

<sup>9</sup> Brint uses the term *early branching system* for the education systems of German-speaking countries. 10 The number of identifiable branches is different between education systems. Some systems distinguish between high, average and low tracks, while others between "selective" and "non-selective" branches only (cf. Greger, 2004).

**Stratification** was understood as the level of internal and external differentiation (tracking) within an education system and the proportion of a given age cohort that attained the highest level of education available within the system (the highest possible number of years of education). The higher the proportion, the less stratified the system. Thus, education system stratification refers to the system's selective character, i.e. the fact that students are sorted into different tracks and how this affects their education prospects. Unsurprisingly, Allmendinger found the German education system to be highly stratified, as opposed to the

Allmendinger's approach is helpful because it provides us with a simple but effective typology of education system, based on a combination of the above two dimensions. Every country's education system can be classified as one of the four resulting types (standardized and stratified, unstandardized and unstratified, unstandardized and stratified, standardized and unstratified). The advantage of this simple typology becomes clear once we realize, along with Allmendinger, that the degrees of standardization and stratification differ between levels of education within many existing education systems. For example, secondary education in the US is non-stratified (with no tracking and no diversity of diplomas) but tertiary education in

As we suggested above, Allmendinger's work had a great impact and was further developed and applied (e.g., Kerckhoff, 2000; Müller & Shavit, 1998). In the following section, we will describe and outline Kerckhoff's approach which adds a third dimension to Allmendinger's original two: the degree of specificity of vocational education12. Finally, it is worth mentioning that while the authors who went in Allmendinger's footsteps developed her approach in many respects, they also frequently introduced great simplification when attempting to operationalize the approach13. Therefore, we can only recommend a critical

Stratification is understood as "the degree to which systems have clearly differentiated kinds of schools whose curricula are defined as 'higher' and 'lower'" (Kerckhoff, 2001: 4). As such, stratification usually takes place at the (lower or higher) secondary level of education.

11 At this point, Allmendinger's concept seems rather inconsistent. When studying stratification in secondary education, the author merely considered the formal existence of different tracks; in contrast, for the tertiary system, she added the criterion of quality and *informal* distinction between different colleges and universities. The question is, would the author label US secondary education as non-

12 One might object here that this dimension is already covered by the stratification level. Indeed, systems grouping students in the general and vocational education tracks are stratified. However, given its importance, we will deal with this aspect separately, along with Kerckhoff. In his latest article on the topic, Kerckhoff (2001) further mentioned a fourth dimension: "student choice". He understood it as the level of flexibility of decisions a given education system allows to students. This aspect is also strongly related to the system's stratification, and therefore, we will not deal with it separately. 13 For example, Kerckhoff (2000) assessed standardization and stratification for education systems *as a whole,* rather than the individual levels of education like Allmendinger did. On the other hand, Müller & Shavit (1998) operationalized stratification simply as level of differentiation (tracking) in secondary

the same country is highly selective, and thus stratified11.

stratified if she approached it in the same way as tertiary education?

reading of the original work.

education.

**4.2 Stratification of education systems** 

US system.


several types of student differentiation and sometimes find it difficult to classify clearly as internal or external differentiation.

Source: Author.

Table 3. Basic types of student differentiation.

We will divide further discussion on differentiation in two parts. First, we will deal with the overall structure of the education system and the ways it affects the reproduction of education inequalities (the problem of branching). Subsequently, we will focus on the school level and what we know about the processes of differentiation taking place there (the problem of tracking and ability grouping).
