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The core idea of logic is to create a system in which communication is clear, precise, and unambiguous, which is (or at least should be) the goal of any website or other communication.
- How humans communicate
- Comparing human and computer communication
- Speaking logically
- Using logical arguments
- Understanding the limits of computer logic
- Formatting information for humans
- Communicating with logic
Skill Level Beginner
We live in a physical world that's governed by the laws of physics. This has made us experts at observing and understanding causation. When I roll a ball across a pool table and hit another ball, the second ball receives the energy from the first and continues rolling. Cause and effect. This understanding of causation gives us an impressive ability to predict future events, at least within a short time frame. If I drop an egg on the floor, it'll break.
If I move the tip of a pencil across a piece of paper. It'll draw a line. Our understanding of causality and the ability to predict the outcome of actions and events is based on logic and observation. You see a sequence of events, one leading to another. And based on this, you create a hypothesis that causality is at play. If you observe the same sequence of events again that hypothesis is strengthened.
If you are able to reproduce the sequence yourself, that hypothesis becomes a theory from which you'll feel secure in making future predictions. This process is so well established that we don't normally think of the actual causal chains. We just expect them to happen, which is why we get profoundly confused when a cause doesn't produce the expected effect. If you look at one of these theories of causation, say drawing a line on a piece of paper with a pencil, we're actually looking at a logical argument.
If I move the tip of a pencil across a surface, and that surface is made of paper, then a line is created. When you look at it this way, it's pretty clear why we get so confused when a cause doesn't produce the expected effect. What we assumed was a valid and sound argument produced the wrong results. This also means we can use our principles of logic to find out what happened. We know that for a conditional argument to produce the wrong result, either the argument is invalid or the premises or statements are not true.
Based on previous observation, we can assume that the argument is valid. So therefore one or both of the premises must be false. Either this is not a pencil, or this is not paper. Our ability to identify causality and our dependence on this causality is an important element of user experience. Knowing that users are looking for cause and effect scenarios and will expect this causal chain going forward, we can create experiences that first hint at cause and effect to instigate the first interaction.
And then repeat that same behavior throughout. One example of this is the way scrolling with mice has changed in the last few years. Originally, scrolling with a mouse was reversed. If you rolled the scroll wheel towards you, the page would scroll up. This made intuitive sense for two reasons. First, moving the scroll bar on the screen down with your mouse would move the page up. Secondly, and maybe not as immediately obvious, if you were actually rolling a wheel on top of a piece of paper, rolling the wheel towards you, would push the paper away.
Then the face of user interaction changed with the introduction of touch screens. For a while, the scrolling behavior was duplicated. But it quickly became clear that when people touched their screens they expected the content on the screen to move in the same direction as their fingers. Up meant up, down meant down. This coincided with the introduction of touch mice without wheels. And soon, the scrolling direction of these mice changed to match the behavior on touchscreens.
So now, when you use a touch pad or touch mouse and you move your fingers up, you're likely to see the page go up. Move them down, and the page goes down. This mimics the natural behavior of touching a screen, or something in real life, and also translates the action performed on the mouse in logical way. You are not turning a wheel, but touching the surface directly. Cause and effect.