Pronunciation: [ɹˈɒkɪˌə͡ʊ] (IPA) 
Rocchio is a surname with Italian origins. In IPA phonetic transcription, its spelling is /rɒkioʊ/. The first two letters "ro" are pronounced with a trilled /r/ sound followed by the short /ɒ/ vowel sound. The "c" in Rocchio is pronounced as a hard /k/ sound before the "i" which is pronounced as a long /iː/ vowel sound. Lastly, the "o" at the end of Rocchio is a schwa sound, which is often not emphasized in spoken language.
Rocchio is a vector space model algorithm used in information retrieval and machine learning for text classification tasks. Named after a computer scientist John Rocchio, the Rocchio algorithm is primarily implemented for relevance feedback, a technique that improves the accuracy of information retrieval systems.
In the context of text classification, the Rocchio algorithm utilizes a set of labeled training documents to create a centroid for each class. Each centroid represents the average representation of the training documents belonging to a particular class. During classification, the algorithm calculates the similarity between the query document and each class centroid. The query document is then assigned to the class with the highest similarity.
The Rocchio algorithm employs the idea of term weighting to boost the importance of certain terms in the vectors. It considers the term frequency-inverse document frequency (TF-IDF) of each word to calculate the weight of the terms. By increasing the weight of discriminative terms and decreasing the weight of less discriminative ones, Rocchio enhances the classification accuracy.
Rocchio is known for its simplicity and efficiency. Even though it is a relatively basic algorithm, it has proven to be effective in various text classification applications, such as spam filtering, sentiment analysis, and document categorization. However, it may face challenges when dealing with high-dimensional datasets or noisy or imbalanced data, which can affect the accuracy of classification results.
