## 3 Theoretical System Construction
### Application of Grounded Theory in Data Classification and Structure Construction
#### 3.2.2 Secondary Coding: Axial Coding Process
Figure 6 shows how the study demonstrates the representative forms of typical phoenix pattern composition through instantiation classification. 3. Colour system dimension. In the \"colour system\" (CYs) dimension, the study systematically identified and coded the colour expression patterns, matching mechanisms and aesthetic trends of phoenix patterns in artistic carriers and physical objects of various dynasties, forming four subcategories: \"main colour category\", \"colour-matching relationship and contrast\", \"colour texture and material sense\", and \"colour and pattern structure fusion\", as shown in Figure 6. This dimension reflects the colour evolution law of phoenix patterns regarding cultural symbolism, aesthetic tonality, and media adaptability. It is also one of the most perception-oriented gene structures in the visual language of phoenix patterns. 4. Element of ornamentation. In the \"pattern element\" dimension, the study takes the smallest configuration unit of the phoenix pattern as the analysis object, focusing on the basic composition logic of its visual language and identifying and constructing eight categories of visual element subsystems, including shape, parts, posture, decoration, frame, plant, abstract variation, etc. The encoding work of this dimension not only realizes the systematic induction of element morphology but also completes the knowledge structure transformation from configuration identification to semantic classification. It is one of the core building blocks in the study of phoenix pattern graphic generation. The phoenix pattern consists of several key element types. The main biological elements -- head, body, wings, claws, and tail -- form the core \"shape\" framework with high recognizability and symbolic continuity. The structural components (e.g., tail feathers, crests) and posture elements (e.g., wing spread, leaping, looking back) enhance the pattern's visual rhythm and narrative expression. Floral elements (e.g., peny, lotus) and border elements (e.g., cirrus, volutes) construct the companion and boundary systems, enriching symbolic meaning and defining image constraints. Decorative accessories like ribbons and pearls strengthen auspicious themes. At the same time, structural combination motifs (e.g., \"double phoenix facing the sun\") follow classical principles such as symmetry and radial layout to create stylized visual units. Finally, abstract and variant forms, including deformation and symbol recombination (e.g., \"meta-deformed phoenix\"), illustrate how phoenix patterns evolve across media and time, forming the basis for their integration into modern design systems (see Figure 6). Compositional schema dimension. In the \"compositional schema\" dimension, the study systematically extracts and summarizes the typical styles and coding structures of phoenix pattern composition in spatial layout, visual organization, and graphic evolution. 5. Media and technology dimension. The dimension of \"media and craft\" is the key channel for the phoenix pattern to transform from a flat symbol to a physical entity, carrying the dual functions of visual structure and material characteristics. Through grounded theory, this study divides this dimension into three substructures: media attributes (MT01), craft techniques (MT02), and composite crafts (MT03). More than 100 typical materials and traditional craft terms are systematically identified to construct the \"physical mapping mechanism\" to generate phoenix pattern images. Regarding media attributes, phoenix patterns are common in jade, bronze, ceramics, lacquerware, and fabrics. Each medium corresponds to a specific visual texture and cultural context. The phoenix pattern on jade ware mostly expresses sacredness through relief and hollowing techniques, while the phoenix pattern on bronze ware emphasizes structural symmetry and power symbols; ceramics use glaze composition to show fluidity, and the phoenix pattern on fabrics relies on embroidery and satin to enhance the soft temperament and is mainly used for clothing decoration.