In addition to the relationship between these theories due to historical development, it is also possible to generate a Venn-diagram to show the complex relationship between these groups of theories, shown in Figure 3. It is important to note that while learning styles serves as a justification for differentiated learning activities, it does not necessarily provide a framwork for how these activities should be structured. This is why learning styles does not appear in Figure 3. A brief overview of these student-centered learning theories and relevant literature is provided in the following (sub)sections.