When I see the example of Gestalt theory, it makes me recall a great toy here http://pya.cc/pyaimg/pimg.php?imgid=12882. Here you can see a woman turning itself, do you think that she turns clockwise or counterclockwise?

Actually, from different people's eyes, there will be different answer. Don't you trust me? I didn't trust it at first, either, but that's ture. Try to ask more friends. If you watch harder, you can switch the way she turns by your will. Though she doesn't change her move at all, you just change your view.

Why do we see different with the same thing? Because it depends on our mind. Everyone's thinking process is not the same, so to make things easy could be more friendly to people. Human-computer interface design is really a great development. I used the DOS system when I was elementary school student. At that time, using computer was a professtional skill because we had to memorize all kinds of commands. Now, even my grandmother could use the computer and play her games. That's all because we have the HCI; it makes the interface more friendly. How can it be friendly? Because it is intuitional. So, the HCI has the relationship with the Gestalt theory in the intuition. HCI could let users connect the icons to its functions, because the Gestalt theory shows that people could use their imagination to make things be organized. It is the same as the GUI; using icons can let users associate more quickly than using words.

The Gestalt theory seems interesting to me, and it is important for the designers to know this knowledge. I think that to know the psychology is very helpful to design everything. I can read something about it and learn more application.