Explaining teachers’ behavioural intentions towards differentiated instruction for inclusion: using the theory of planned behavior and the self-determination theory

ABSTRACT

A cornerstone of inclusive education is teacher’s readiness to respond adequately to different educational needs of students in their diverse classroom. Differentiated instruction, referring to the process by which teachers carefully monitor students’ needs and progress, and adapt their instruction according to these differences, is a means to meet the needs of students of different levels. High-quality differentiated instruction is a complex process for teachers which needs careful preparation. This makes teachers’ intentions relating to differentiated instruction particularly relevant. In this article we compare two theoretical models to explain teachers’ intentions to differentiate: the Theory of Planned Behavior (TPB) and Self-determination theory (SDT). Secondary school teachers (n = 180) responded to a questionnaire in which we measured their intentions and predictor variables relating to both of the theoretical models. Linear regression showed that both the TPB as well as the SDT model significantly predicted teachers’ intentions (p < .01), but that the TPB model showed a better fit with the data (48 versus 32% explained variance). We conclude that in addition to the factors included in the TPB, autonomy might be a relevant factor in explaining teachers’intentions.

KEYWORDS:

• Differentiated instruction
• inclusion
• teachers
• attitudes
• behavioural intentions
• self-determination

Introduction

During the past decades, there has been an increasing awareness that more effort should be made to make educational systems throughout the world more inclusive. In line with the UN declaration, inclusive education implies that all member states of the UN ensure that ‘persons with disabilities can access an inclusive, quality and free primary and secondary education on an equal basis with others in the communities where they live’. (CRPD art. 24.2). In order to realise inclusive education, the member states of the UN commit to providing ‘effective individualised support measures in environments that maximise academic and social development, consistent with the goal of full inclusion’ (CRPD art. 24.2). The question remains how the philosophy of inclusion and the provision of individualised support can be translated to everyday classroom practices. This study aims to clarify why some teachers are better able than others to support students’ different educational needs by looking at their behavioural intentions.

One immediate consequence of striving towards inclusive education, is more attention for diversity in the classroom. Teachers are on the one hand more aware of different (special) educational needs of their students and report increased levels of students with special educational needs (Smeets et al. 2019) and on the other hand, are increasingly expected to deal effectively with differences between students in the classroom. Differentiated instruction refers to the teacher’s practice of carefully monitoring student needs and progress and consequently adapting instruction to differences in needs and progress (Deunk et al. 2018; Smale-Jacobse et al. 2019), and ideally also to different interests of student (Tomlinson et al. 2003).

Although differentiation is considered a cornerstone of high-quality education, it is also a notoriously difficult skill for teachers (van de Grift, Helms-Lorenz, and Maulana 2014; van Geel et al. 2019). In order to adapt to students’ needs, teachers first have to have a thorough understanding of what those needs are (for instance, by collecting information about students’ previously acquired skills, progress, interests and motivation). Second, teachers need to plan what goals individual students, and the class as a whole, strive for, and plan for adapting instruction, resources etcetera in order to meet these differentiated goals. This means that differentiation occurs not only in the lesson itself, but also relies heavily on pro-actively planning and collecting data during the preparation of the lesson(s) (van Geel et al. 2019).

The first step towards pro-actively planning for differentiated instruction and inclusive education, are behavioural intentions. It is precisely because differentiated instruction and provision of individual support are complex skills for teachers, that they need to consciously prepare their lessons with differentiated instruction in mind. Therefore, if we better understand where differences between teachers in behavioural intentions towards inclusive education in general and towards differentiated instruction in particular stem from, we better understand a key aspect of why some teachers are able to differentiate according to the diverse needs of students, while other teachers struggle to do well in this aspect.

Two theoretical frameworks can be used to explain teachers’ motivations and intentions for engaging in, in this case, behaviours that either facilitate or hinder inclusive education and differentiated instruction. The first is the Theory of Planned Behavior (TPB; Ajzen 1985). This theory links behavioural intentions and to behaviour, that is, the assumption that human behaviour can be explained rationally as stemming from behavioural intentions. The three main factors influencing these intentions are a person’s attitudes, subjective norms and perceived behavioural control. With regard to attitudes, a distinction can be made between cognitive attitudes and affective attitudes (e.g. beliefs about differentiated instruction and feelings of competence). Subjective norms refer to a person’s perception of how relevant others would perceive the behaviour. And perceived behavioural control (a concept very similar to self-efficacy) is the degree to which an individual feels capable to execute the behaviour.

The TPB has been used frequently to study teachers’ behavioural intentions and, to a lesser extent, actual behaviours (e.g. Teo 2012; Voet and De Wever 2020). Regarding inclusive education, we know that regular education teachers tend to hold negative to neutral attitudes towards students towards students with special educational needs (De Boer, Pijl, and Minnaert 2011). Teacher’s attitudes towards inclusion indeed predict their behavioural intentions aimed at inclusive practices (Kisbu-Sakarya and Doenyas 2021). Teacher’s perceived subjective norms about inclusive education also related to their behavioural intentions (MacFarlane and Woolfson 2013). Similarly, teachers’ self-reported differentiated instruction practices could also be predicted from their beliefs or attitudes and self-efficacy (Whitley et al. 2019).

Although the TPB is widely used in the field of education and beyond, it is far from free of criticism. Several authors argue that motivational concepts might be more valid predictors of human behaviour (Sniehotta, Presseau, and Araújo-Soares 2014). The most well-known theory of motivation is the self-determination theory (SDT, Deci and Ryan 1985). The theory states that all human beings have three basic psychological needs: the need for autonomy, competence, and relatedness. The need for competence shows close resemblance with the sense of perceived competence in the TPB and with self-efficacy (Bandura 1977). The fulfilment of all three these psychological needs is according to the theory a necessary precondition for intrinsic motivation which results into behaviour. Satisfaction of the basic psychological needs has been related to teachers’ willingness or motivation to partake in educational innovations (Sørebø et al. 2009). A qualitative study by MacCormack et al. (2021) looked at how principals could motivate teachers for inclusive educational practices and found supporting the three needs of the SDT to be crucial in this aspect.

Teachers’ backgrounds also seem to matter when it comes to predicting their (intended) differentiation behaviour. Both the quality of teacher’s initial training (Hartwig & Schwabe, 2018) as well as professional development (Dixon et al. 2014) are facilitators for teachers’ differentiation practices. The role of work experience is more ambiguous. On the one hand, there is research pointing at a summative model of teacher skills, which implies that teachers first need to master more basic skills such as classroom management before they can learn to effectively implement differentiated instruction (van de Grift, Helms-Lorenz, and Maulana 2014). On the other hand, beginning teachers might be more open to trying out educational innovations such as differentiated instruction. Suprayogi et al (2017) did not find a significant relation between work experience and differentiated instruction. Dias and Cadime (2016) found that having more experience with teaching special needs students resulted in slightly fewer positive intentions towards inclusion.

Both the TPB and the SDT have been used in investigating the factors influencing teachers’ behaviours and intentions towards inclusion and differentiation in the classroom, and we expect that the factors explicated in both theories relate to teachers’ behavioural intentions. To the best of our knowledge, however, no study exists that directly compares the predictive value of these two widely-used theoretical frameworks. This is a necessary advancement, both needed to further theory formation on factors impacting on inclusion through teacher behaviour, as well as to inform interventions aimed at improving teachers’ readiness to effectively deal with differences between students, a key element in realising inclusive education. Therefore, our current study aims to do exactly that. This translates to the following research questions:

1. To what extent can regular education teachers’ behavioural intentions towards differentiated instruction be explained by factors specified in the Planned Behavior Theory (attitude, perceived behavioural control, and subjective norms)?

2. To what extent can regular education teachers’ intentions towards differentiated instruction be explained by factors specified in the Self-determination Theory (need for autonomy, competence, and relatedness)?

3. To what extent do teachers’ work experience and differentiation training relate to their intentions to differentiate?

Method

Design and procedure

A cross-sectional, online survey study among regular secondary school teachers was set up to answer the research questions and was part of a larger study on differentiated instruction of teachers in regular secondary education. The study was approved by the Ethical Committee of [BLINDED] (d.d. October 8th 2016). Teachers were recruited through social media and the personal network of the researchers.

Participants

Our research population consisted of Dutch teachers in regular secondary education. With respect to the aim of the study, it is important to note that a) the secondary school system is externally differentiated by dividing students from age 12 onwards into tracks based on student performance, and b) the school system strives to be more inclusive but special schools still exist. A sample of 180 teachers (78% female) completed the survey. Somewhat more than half of the participants were between 21–40 years old. Twenty-five percent were between 41–50 years old, and twenty-two percent were 50+ years old. This resembles the distribution of the years of teaching experience: 28% of the teachers has <5 years of teaching experience, 22% 6–10 years, 17% 11–15 years, 13% 16–20 years and 20% >20 years of teaching experience. Sixty-five percent of the participants hold a degree to teach all classes in both lower and higher levels of secondary education. Twenty-four percent hold a degree to only teach the first classes in the higher track of secondary education, and all classes in lower secondary education. Six percent did not have an educational degree at all, and 4% hold another degree. Thirty-three percent of the participant followed a specific training related to the topic of differentiation.

Instruments

Dependent and independent variables from both the TPB and the SDT are described in Table 1.

Table 1. Summary of the included variables.

Scale	Nr. of items	Example of an item	Reliability coefficient (α)	Based on previous instrument
Dependent variable				TEIP* (Park et al. 2016)
Behavioral intentions	6	I am willing to adjust the curriculum to the individual needs of all students, regardless their abilities.	0.81
Theory of Planned Behavior variables				TEIP
Attitudes	12	I belief that every student can learn in regular education, when the curriculum is adapted to the students’ needs.	0.82
Perceived behavioural control	12	I can give an alternative explanation or an example when a student does not understand something.	0.81
Subjective norms	12	My manager finds it important that I can give an alternative explanation or an example when a student does not understand something.	0.89
Self-Determination Theory variables				BPNSFS (van der Kaap-Deeder et al. 2015)
Perceived BPN total	12		0.87
Perceived autonomy	4	I feel autonomy in my choices when applying differentiation.	0.75
Perceived competence	4	I have faith in being able to differentiate.	0.91
Perceived relatedness	4	I feel related to the people at work who I care of.	0.90

*While ‘inclusive practices’ are broader than differentiated instruction only, we based our items specifically on the items relating to adapting instruction to student needs.

Analysis

Analyses were performed using SPSS (version 26). We first ran descriptive and correlational analyses. We then tested the relationship between the background variables and the dependent variables (research question 3) with univariate regression analyses. Through stepwise regression we built two regression models: one to test the relationship between the TPB variables and behavioural intentions (research question 1) and the second the test the relationship between the SDT variables and behavioural intentions (research question 2).

Results

Descriptive statistics

Teachers are overall neutral in their behavioural intentions (see Table 2). Teachers’ attitude scores are most positive regarding the items measuring the affective component (M = 4.05, SD = 0.97), compared to the cognitive component (M = 3.48, SD = 0.48). When looking at the other variables of the Theory of Planned Behaviour, it turns out that teachers are slightly positive regarding the subjective norms and their perceived behavioural control.

Table 2. Summary of the descriptive statistics of the measured variables.

Variable	M	SD
Behavioral intentions	4.53	0.80
Attitudes	3.76	0.79
Perceived behavioural control	4.67	0.57
Subjective norms	4.87	0.62
Total perceived BPN	4.25	0.93
Perceived autonomy	4.10	0.97
Perceived competence	3.99	1.07
Perceived relatedness	4.69	1.00

Overall, teachers’ evaluation of the basic psychological needs is neutral. Teachers are least positive in their perceived competence compared to the other two psychological needs. The perceived relatedness is scored as most positive, as can be seen in Table 2.

Correlation analysis, shown in Table 3, shows that, as expected, attitude scores are positively and significantly correlated with behavioural intentions (r = .63, p < .01). Perceived control and subjective norms show significant, positive, relationships as well, albeit less strong ones (r = .40, p < .01 and r = .32, p < .01).

Table 3. Correlations between variables.

	Beh. intentions	Attitude	Perceived control	Subjective norms	Perceived Autonomy	Perceived Competence	Perceived Relatedness
Behavioral intentions	1	.63**	.40**	.32**	.57**	.44**	.18*
Attitude		1	.33**	.09	.50**	.39**	.15*
Perceived control			1	.31**	.48**	.62**	.17*
Subjective norms				1	.32**	.24**	.27**
Perceived Autonomy					1	.75**	.24**
Perceived Competence						1	.18*
Perceived Relatedness							1

**Significant correlation at p < .01.

*Significant correlation at p = .05.

The basic psychological needs variables all three show a positive, significant, relationship with behavioural intentions of teachers. The relationship with perceived autonomy is most strong (r = .57, p < .01), together with the perceived competence (r = 0.44, p < 0.01). Less strong, though still significant, is the relationship between perceived relatedness and behavioural intentions (r = .18, p < .01).

None of the background variables (e.g. years of teaching experience and received training) showed a significant relationship with the behavioural intentions. Hence, the variables were not considered in the final analysis.

Explaining the behavioural intentions

The regression model including the TPB variables shows, overall, a positive and significant model (F(3) = 55.13, p < 0.01). The model statistics showed that attitudes most strongly predict teachers’ behavioural intentions, together with subjective norms. The model explains 48% of the variance in behavioural intentions.

The regression model including the SDT variables shows, overall, a positive and significant model. Yet, this model only includes the perceived autonomy as independent variable (F(1) = 78.86, p < 0.01). The other two variables are excluded in the model due to a non-significant contribution. The final model explains 32% of the total variance in behavioural intentions (see Table 4).

Table 4. Summary of the regression analyses.

Variable	B	SE B	β	t-value	Sig.
TPB model^1
Constant	0.80	0.44		0.18	.86
Attitudes	0.57	0.06	0.57	9.88	<.01
Perceived control	0.19	0.08	0.14	2.30	.02
Subjective norms	0.29	0.07	0.22	3.90	<.01
SDT model^2
Constant	2.20	0.27		8.31	<.01
Perceived autonomy	0.52	0.06	0.57	8.88	<.01

¹TPB model: R² = 0.48.

²SDT model: R² = 0.32.

Conclusion and discussion

The aim of our study was to compare two leading motivational theories, the Theory of Planned Behavior (TPB) and Self-determination theory (SDT) in their power to explain individual differences in teachers’ intentions to engage in differentiated instruction and inclusive practices. Our results show that the TPB model fitted the data best. All three factors explicated in that theory, namely teachers’ attitudes, subjective norms as well as perceived behavioural control, related to teachers’ intentions to implement differentiated and inclusive practices in their classroom. Regarding the model based on self-determination theory, only teachers’ perceived autonomy related to their behavioural intentions.

Although both theories aim to explain underlying factors in ultimately explaining why people behave in a certain way, there is a significant difference. The TPB tries to explain concrete behavioural intentions (in this study, behaviours relating to differentiated instruction and inclusive practices) (Ajzen 1985). Self-determination theory was primarily developed to explain people’s intrinsic motivation and well-being (Deci and Ryan 1985). Teachers’ behavioural intentions and their motivation are overlapping, and both relevant concepts. On the shorter term, concrete and positive behavioural intentions hopefully translate into differentiated and inclusive practices. On the long term, however, experiencing agency and self-determined motivation is also important in engaging in demanding processes such as differentiation. And indeed, we found autonomy to also be a relevant factor in teachers’ behavioural intentions. Teachers’ sense of autonomy is a relevant contributing factor in their intentions that the TPB is currently lacking.

Teachers’ work experience and training regarding differentiation did not relate to their intentions. Training with regard to differentiation can refer to many different things, ranging from one or two lectures on the topic to an intensive professional development intervention directed to this topic. From the professional development literature, there is ample evidence that the quality of both the content and the form of the intervention matter with regards to sustainable outcomes (Postholm 2012; Van Veen et al., 2012). That is, professional development interventions (as a part of implementation of for instance differentiated instructions have a much higher chance of improving teacher instruction in the classroom if these interventions are directed at the didactical content of the lesson, if the intervention lasts long enough and if the school organisation facilitates sustainable professional development. Concluding, only high quality, sustainable professional development (as opposed to any kind of ‘training’) might impact on teachers’ intentions.

Limitations and recommendations

As indicated in the Introduction, a central assumption of the TPB is that behavioural intentions steer actual behaviours. Intentions are not a perfect predictor of actual behaviour, which we did not consider in this study. In the messy, fuzzy reality of the classroom, intentions might not be realised as planned. The flexibility to adapt to the real-time dynamics and needs of students in the classroom is more than an obstacle for implementing differentiation; it can indeed be considered part of inclusive practice (Sawyer 2011). For a more comprehensive understanding of how differentiated instruction is realised, we recommend that intentions are linked to observational assessment of differentiated instruction (e.g. van Geel et al. 2019).

Another limitation is that while we aimed to explain individual differences in teachers’ behavioural intentions, we did not look at how these differences arise in the context of the school organisations. Future research should dive into how behavioural intentions are supported within different layers of the school organisation. The student population is also a relevant factor in the school context, both in terms of their background characteristics as well as the students’ perception of the quality of differentiated instruction and teacher-provided support which can be included in future research.

In terms of methods, the recruitment of teachers via social media and the researchers’ networks can be considered a limitation because of sampling and response bias. The teachers’ responses, however, are in line with previous research (i.e. on attitudes (De Boer, Pijl, and Minnaert 2011).

Notwithstanding these limitations, by means of the critical comparison between two leading educational theories of teacher behaviour, the current study added to the literature on differentiated instruction in particular and teacher professional development in general.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The study was funded by the national funding body for educational research (NRO) (project number 405-17-302).