Parc: Contrast
Brigham Young University, Hawaii
Brigham Young University, Hawaii

Contrast is one of the most powerful design concepts of them all because really any design element can be contrasted with another In their website you can see difference in the elements. Images on the website also helps acentuate that contrast.They do a good job on differenciating important information.
Parc: Proximity
Amazon
Amazon

The principle of proximity is about moving things closer or farther apart to achieve a more organized look. In this website the proximity is not very good. There are so many little images all together and they don't look good and they are very distracting.
Parc: Repetition
Church of Jesus Christ of Latter Day Saints, Family Search
Family Search

The principle of repetition simply means the reusing of the same or similar elements throughout your design.In the family seacrh website of you click on the top right you will see a good example. Under every option you see a couple of options. The same pattern happens with every option and I think that makes it easier