Rule 16 EXPRESS RELATED ELEMENTS IN A SIMILAR MANNER
The principle of grouping brings clarity to any design by signaling the purpose of each element. Related elements should look alike, and unrelated elements should look different.
For example, the designer of a smartphone app can create a similar look for each of its functional icons, expressing that these functions are of the same type or have the same level of navigational importance.
The leader of a company can direct the actions of employees by organizing her expectations into a long-term purpose, a medium-term mission, and a series of short-term goals, so every employee knows what to do, ...