**3. Results**

The results for the complete set of source articles studied (1982–2017) indicated that at least 16 dimensions were significant, meaning they had eigenvalue scores greater than 1.0 (**Table 1**). The eigenvector coefficients for the first four dimensions are included in **Table 2** to illustrate eignevectors from the tables. The complete tables are too extensive to print in this book chapter; however, they are available from the corresponding author. Across different time frames, the number of dimensions ranged for 14 to 17significant dimensions. The large number of dimensions suggest a fair number of topics are being studied within the profession. There is great diversity in what landscape scholars study and what comprises the breadth of the landscape discipline.

Twenty-two subjects were found in the study of the curriculums for the fifteen top 2016 undergraduate school in the United States, PCA analysis revealed that the subjects could be compacted into fourteen dimensions (**Table 3**). **Table 4** illustrates the first two eigenvector coefficients for the first two eigenvalues from **Table 3**.

#### *Landscape Architecture Framed from an Environmental and Ecological Perspective*


#### **Table 1.**

*Eigenvalue scores for the set of source articles from 1982 to 2017.*



*The American Landscape Architecture Research Universe and a Higher Education Ordination… DOI: http://dx.doi.org/10.5772/intechopen.99119*

*Note: \*Bold\* coefficients in red indicate categories with a \*strong\* association for a particular principal component (dimension); \*Italic\* blude coefficients indicate categories with \*a modest\* association for a particular principal component (dimension); \*Underlined\* coefficients indicate categories associated with more than one dimension.*

#### **Table 2.**

*Eigenvector coefficients for the first four dimensions from source articles 1982 to 2017.*
