User based filtering:Recommendation system
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I know this is not a coding specific problem but this is the most suitable place for asking such questions.So please bear with me.

Suppose I have a dictionary like given below,listing ten liked items of each person

    likes={
    	"rajat":{"music","x-men","programming","hindi","english","himesh","lil wayne","rap","travelling","coding"},
    	"steve":{"travelling","pop","hanging out","friends","facebook","tv","skating","religion","english","chocolate"},
    	"toby":{"programming","pop","rap","gardens","flowers","birthday","tv","summer","youtube","eminem"},
    	"ravi":{"skating","opera","sony","apple","iphone","music","winter","mango shake","heart","microsoft"},
    	"katy":{"music","pics","guitar","glamour","paris","fun","lip sticks","cute guys","rap","winter"},
    	"paul":{"office","women","dress","casuals","action movies","fun","public speaking","microsoft","developer"},
    	"sheila":{"heart","beach","summer","laptops","youtube","movies","hindi","english","cute guys","love"},
    	"saif":{"women","beach","laptops","movies","himesh","world","earth","rap","fun","eminem"}
    	"mark":{"pilgrimage","programming","house","world","books","country music","bob","tom hanks","beauty","tigers"},
    	"stuart":{"rap","smart girls","music","wrestling","brock lesnar","country music","public speaking","women","coding","iphone"},
    	"grover":{"skating","mountaineering","racing","athletics","sports","adidas","nike","women","apple","pop"},
    	"anita":{"heart","sunidhi","hindi","love","love songs","cooking","adidas","beach","travelling","flowers"},
    	"kelly":{"travelling","comedy","tv","facebook","youtube","cooking","horror","movies","dublin","animals"},
    	"dino":{"women","games","xbox","x-men","assassin's creed","pop","rap","opera","need for speed","jeans"},
    	"priya":{"heart","mountaineering","sky diving","sony","apple","pop","perfumes","luxury","eminem","lil wayne"},
    	"brenda":{"cute guys","xbox","shower","beach","summer","english","french","country music","office","birds"}
    }

How can I determine persons who have similar likes.Or maybe who two persons resemble the most.Also it will be helpful if you can point me to the appropriate example or tutorial for user based or item based filtering.