Sight Distance and Reaction Time. Sight Distance. Sight distance means the distance from which you can see and identify a hazard. You often see an object before youâre able to identify it as a hazard. If the stopping distance to an object is greater than the sight distance, youâre in danger of hitting the object.
The major methodology of this approach is the single-case experiment, or N = 1 design. Although there are many kinds of N = 1 designs, the most common are the ABAB design and the multiple-baseline design. An ABAB design, or reversal design, allows a researcher to confirm a treatment effect by showing that behavior changes systematically with conditions of No Treatment (baseline) and Treatment.
Every so oftenâevery 250,000 years on averageâthe Earth's magnetic poles reverse polarity. If such a reversal happened today, compass needles would point south rather than north. Here, view a computer-model-generated animation of our planet's magnetic field, and see what happens during a reversal.To learn how Earth's magnetic field works, see text below. Launch Interactive. Watch a simulated reversal of Earth's magnetic field, from the first signs of instability to the final, inevitable flip.f such a reversal happened today, compass needles would point south rather than north. Here, view a computer-model-generated animation of our planet's magnetic field, and see what happens during a reversal.