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.
The reversal design can be extended indefinitely. A standard variation is the BAB design. The main disadvantage of the ABA design is its inability to be used with variables with irreversible effects or when it is undesirable to return to a baseline condition for practical or ethical reasons.