text: Carter and Wegman proposed a method of creating these structures that randomly selects one of a familyof sequences.
full_question: Carter and Wegman proposed a method of creating these structures that randomly selects one of a familyof sequences. That method is "universal", and a "perfect" method can be used when the set they contain isstatic. Primary clustering in these structures can be avoided using quadratic probing. Assuming simpleuniform conditions for one of these structures gives big theta of alpha plus one average-case search time,where alpha is these structures's load factor. Chaining and open addressing are two methods of preventingcollisions in these data structures. They can be searched in average-case constant time. For 10 points, namethese data structures that store keys in array indices given by their namesake functions. 
first_sentence: Carter and Wegman proposed a method of creating these structures that randomly selects one of a familyof sequences.
raw_answer: hash tables