Answer:
The three levels of processing are - 
1. Structural processing (Part of shallow Processing)
2. Phonemic processing (Part of shallow Processing)
3. Semantic processing (Deep Processing)
Explanation:
Craik and Lockhart in 1972 defined three levels of processing of memory –  
a)	Shallow Processing – In shallow processing, repetition is done to hold the memory of   things. It has two forms  
1.	Structural Processing - The physical qualities associated with something is processed at this level of memory processing. 
For example – colour, shape, size etc. of any object
2.	Semantic processing – The sound associated with something is processed at this level 
b. Deep Processing – 
3. Semantic processing - At this stage the meaning associated with a word is encoded. It is an in-depth analysis of information which helps in recalling the things.