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.
The Himalayas are very useful to India in many ways. The Himalayas form a strong natural barrier to our country in the North. It is very difficult to cross these high mountains. It can only be crossed in summer when snow melts over its passes. For centuries, it has stood as a strong defense wall for the country. The other advantages of Himalayas are as under: (i) Climatic barrier : The Himalayas are a great climatic barrier. They save our country from the cold and dry winds of Central Asia, It also prevents the rain-laden monsoon winds of Indian Ocean from crossing over to Northern countries and causes heavy rain-fall in the Northern India.