Abstract: The web has recently become a powerful platform for retrieval of Information and discovering knowledge from web data. The beginning of discovering useful patterns in data has been given a variety of names like data mining, knowledge extraction, discovery of information and data pattern processing. Web mining is the application of data mining techniques for knowledge drawing out from web data. The data is collected from web server when the web accessed by user. First perform the preprocessing for finding access pattern because, raw data which is collected from the web server is incomplete. The aim of this paper is to understand the preprocessing of usage data and also the discovery of Patterns and their analysis. The discovery and analysis of patterns focuses on data accessed by the user. Web browsing behavior of users is captured by Web usage data through web site. User activities are stored in web logs. Due to more usage, the files in log are increasing at higher rate in size. The Preprocessing plays an important role in efficient mining process as Log data is normally noisy and not distinct.

Keywords: Web Usage Mining, Data preprocessing, Pattern discovery, Pattern analysis.