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 ecosystem is first defined in terms of slope and elevation. Also, altitude and proximity to oceans help characterize the climate, making some mountains wet, some dry, and others more seasonal. There are three main altitude belts for a mountain ecosystem. The montane belt is the forested region.