Top 5 quiz questions in IR, Information retrieval quiz, information retrieval mcqs with answers, information retrieval, classic retrieval models, inverted index, precision, recall, query expansion, relevance feedback questions
Information Retrieval MCQs - SET 01
1. Which of the following is/are
classical IR models?
a) Vector model
b) Boolean model
c) Interaction model
d) Cluster model
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Ans : (a) and (b)
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Answer: (a)
Vector model, and (b) Boolean model
Vector model - It
represents documents and queries as vectors of weights. Each weight is a
measure of the importance of an index term in a document or a query,
respectively. The index term weights are computed on the basis of the
frequency of the index terms in the document, the query or the collection.
Boolean model – This
model is based on Boolean logic and set theory. In this model, users are
required to express their queries as a boolean expression consisting of
keywords connected with boolean logical operators (AND, OR, NOT). Retrieval
is performed based on whether or not document contains the query terms.
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2. What is the disadvantage of Boolean
retrieval model?
a) Easy to implement
b) Difficult to rank output
c) Difficult to process a query
d) It is one of the complex retrieval
models
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Ans : (b)
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Answer: (b)
Difficult to rank output
It is difficult
to rank the documents. As per the Boolean model, all matched documents
logically satisfy the query. All terms are equally weighted.
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3. An inverted index is a database
index that ____.
a) stores, for each term t, the list
of all documents that contain term t
b) stores mapping from documents to
words
c) orders the terms in a different
order which is not a sequential order.
d) All of the above
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Ans : (a)
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Answer: (a)
stores, for each term t, the list of all documents that contain term t
Inverted index is
a word-oriented mechanism for indexing a text collection to speed up the
searching task. The inverted index structure is composed of two elements: the
vocabulary (term) and the occurrences. The vocabulary is the set of all
different words in the text. For each word in the vocabulary the index stores
the documents which contain that word (inverted index).
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4. For a query, a retrieval system
retrieves 42 relevant documents and 34 irrelevant documents from a document collection
that consists of 95 relevant documents. What is the precision of the retrieval
system?
a) 0.40
b) 0.50
c) 0.62
d) 0.55
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Ans : (d)
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Answer: (d)
0.55
Precision = (Total
# of documents retrieved that are relevant) / (Total # of documents that are
retrieved)
= 42 / (42 + 34) = 42 / 76 =
0.55
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5. Which of the following techniques
tries to improve recall of an information retrieval system by adding synonyms to
the query?
a) Query expansion
b) Relevance feedback
c) Pseudo relevance feedback
d) None of the above
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Ans : (a)
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Answer: (a)
Query expansion
Query expansion
is a technique to improve recall of a retrieval system by adding synonyms or
related terms to the original query. It is done using global sources like
thesaurus, query logs, WordNet etc.
Relevance
feedback is another method to improve recall. It is based on choosing the
relevant and non-relevant documents from the initial retrieval results. This feedback
is given to the IR system to improve. It doesn’t add related terms to the
query like query expansion.
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Related links
Keywords
Information retrieval quiz questions with answers
How to improve recall of an IR system
What are the classical IR models
How to calculate precision of a retrieval system
Define the term inverted index
List the disadvantage of boolean retrieval model
