Distinguish between full goodwill method and Partial goodwill method?

The partial goodwill method ,where you measure the asset's and liabilities but recognise only the goodwill associated with the controlling interest in the company ,full goodwill method which is fundamentally the same as the partial method except that th non controlling interest include goodwill.

Full goodwill means that the goodwill is recognised in a business combination for the NCI in a subsidiary as well as the controlling interest.

A partial goodwill acquirer may recognise NCI in the subsidiary at fair value or the acquirer can recognize NCI in net assets excluding goodwill. Normally, under partial goodwill method the subsidiary goodwill is not calculated.

Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants (IFRS 13).

IFRS 3 (revised) gives the option of valuing NCI at fair value. The thinking behind this is that the NCI also owns some of the goodwill  in the subsidiary, and thus the traditional method of consolidation does not show this goodwill. The standard suggest that the closest  approximation for fair value will be the market price of the shares held by NCI shareholders just  before acquisition by the parent.

 

I am very confused between the Partial and Full goodwill method. Can someone please help me in understanding the logic behind these two methods so that I don't have to learn the formula by rote.

 

These are the few things that I don't understand-

1. Why do we take fair value of the sub while calculating Non Controlling Interest (NCI) under full goodwill?

2. Why do we take fair value of net assets of the sub while calculating Non Controlling Interest (NCI) under partial goodwill?

3. And whats the difference between fair value of sub and fair value of net assets of sub?