In the hypothesis testing approach of Jerzy Neyman and Egon Pearson, a null hypothesis is contrasted with an alternative hypothesis, and the two hypotheses are distinguished on the basis of data, with certain error rates. Proponents of each approach criticize the other approach.
In geography, relief refers to the highest and lowest elevation points in an area. Mountains and ridges are typically the highest elevation points, while valleys and other low-lying areas are the lowest. Relief is essential to understanding the topography of an area.
a large natural elevation of the earth's surface rising abruptly from the surrounding level; a large steep hill: the village is backed by awe-inspiring mountains we set off down the mountain | [as adj.] the ice and snow of a mountain peak. â (mountains) a region where there are many such features, characterized by remoteness and inaccessibility: they sought refuge in the mountains | [as adj.] (mountain) his attempt to picture the mountain folk in ridiculous attire. â (a mountain ...