1. One of the most common types of information retrieval processes is document database searching. An experiment was conducted to investigate the variables that influence search performance in the Medline database and retrieval system. Simple linear regression was used to model the fraction y of the set of potentially informative documents that are retrieved using Medline as a function of the number of x of terms in the search query based on a sample of n = 124 queries. The results are summarized below:

Y = . 202 + . 135x t(for testing Ho : 1 = 0) = 4.98

Two tailed p-value = . 001

Required:

a. Is there a sufficient evidence to indicate that x and y are linearly related? Test using = .01 (4 marks)

b. If appropriate, use the model to predict the fraction of documents retrieved for a search query with x = 3 terms