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 mountain range (also mountain barrier/belt/chain/system) is a geographic area containing numerous geologically related mountains. A mountain system or system of mountain ranges, sometimes is used to combine several geological features that are geographically (regionally) related.he belt also includes other European and Asian mountain ranges. The Himalayas contain the highest mountains in the world, including Mount Everest, at 8,848 metres (29,029 ft) of elevation, at Nepal.