Paper For Above instruction
Collect and preprocess 10,000 web documents from memphis.edu
The task involves designing a comprehensive system to automatically collect, process, and index a large corpus of web documents from memphis.edu, ensuring that the data is suitable for subsequent information retrieval and analysis tasks. The project is divided into two main parts: document collection and preprocessing. Each phase requires meticulous implementation to meet specified criteria, including quality, format, and data integrity.
Part 1: Automated Collection of Web Documents
The first step in the project focuses on the extraction of 10,000 unique web documents from memphis.edu. This process entails developing a custom web crawler that can systematically navigate the site, identify relevant web files, and convert them into plaintext documents. Crucially, the crawler must be built from
scratch—using no existing third-party crawling libraries—to fulfill the assignment's requirement for originality and technical depth.
The crawler should target specific file types—namely HTML, TXT, and PDF files—deriving plain text from each. During the extraction, presentation elements such as HTML tags must be stripped out to retain only meaningful textual content. Additionally, each collection process must verify that the extracted text contains at least 50 valid tokens, ensuring the documents are substantial enough for analysis. Files that do not meet this threshold should be discarded.
Each valid document must be saved as a text file, with a strict output count of 10,000 such files. Simultaneously, the system should record the original URL of each document, storing this metadata to facilitate future referencing and display. This ensures traceability and supports subsequent tasks such as corpus analysis or user query relevance assessment.
Part 2: Preprocessing and Indexing of Collected Documents
Following collection, the second phase involves processing the gathered documents using a detailed preprocessing pipeline. This pipeline is based on prior assignment guidelines yet must be enhanced with specific techniques recommended during the "Text Operations" lecture.
A dedicated Python program should be developed to intake a directory containing the 10,000 text documents. Preprocessing steps include:
Removing digits and punctuation
Eliminating stop words, utilizing the provided stopword list located at ...ir-websearch/papers/english.stopwords.txt
Stripping URLs and HTML-like strings
Converting all text to lowercase
Removing morphological variations (e.g., stemming or lemmatization)
The output of this process should be cleaned, normalized text files stored in a single directory. Additionally, an inverted index should be constructed, capturing the raw term frequency (tf) within each document—without normalization. The index must also include document frequency (df) counts for each term, enabling later retrieval and analysis. It is essential to save this index in a file structure that permits
future access for tasks such as search queries or statistical analysis.
Proper documentation of the collected data and the preprocessing results, including the indexing, will support subsequent information retrieval experiments and demonstrate the effectiveness of the developed system.
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