Tile is a small object including an RFID as described in Chapter 3 of "The Computer." The advantages of these devices are easily understood, but privacy could be a concern, as well. As suggested by Ince, many individuals are uncomfortable with their personal locations can be monitored. Tile's ability to send your location to other Tile users could make some uncomfortable with the concept. As someone who misplaces my keys regularly, I am willing to take the privacy risk!
This page goes into depth about space as discussed in Chapter 3 and has more images so it is easier for me to see the positive/negative space for example.
Chapter 3: Tying into contrast with color -- a series of links to check the accessibility of your website and make sure the contrast is appropriate/functional.
Balance is one of the important points the success of a design. Everyone loves the convenience to what they see. Balance in graphic design can be achieved by adjusting the visual weight of each element, both in terms of scale, color, contrast, etc.
This page first lets you know what contrast is and how you use it and then goes on to give examples of contrast and how it can be used. This page and the examples are very helpful for beginners.
This site reinforces the principle of contrast. I like the definition that it provides. "Contrast makes a page more interesting so the reader is more apt to pay attention to what is on the page."
This is a great tutorial on all the four basic design principals. The creator has made remember the principals of design easy by calling it the C.R.A.P design principals. C.R.A.P standis for contrast, repetition, alignment and proximity.
CONTRAST. This website also deals a lot with what contrast is but it mostly highlights why it's necessary for a format to have contrast in it. I like this website a lot and think that it's very straight to the point and concise with its purpose.