please tell me whether while calculating ranks for the x values should it be calculatedsuch that the largest no. receives the rank 1 or can it be calculated inthe ascending order of x values.

whose method do we use for the calculation of correlation coefficient in direct method?

The ranks can be assigned in both the ascending order as well as descending order. That is, highest rank can be accorded to the lowest value in the series or to the highest value. However, a uniformity must be followed while assigning rank in the X series and the Y series. That is, in the X-series if highest value in the series is accorded the highest rank then, in the Y - series also highest value should be assigned the highest rank. 

In other words, either the ascending order or the descending order of assigning the ranks can be followed, however precaution must be taken to follow the same method in both the series. 

In calculation of correlation coefficient using the direct method, Karl Pearson's method is used.