Data Preparation for Data Mining- P3

... Transformations and Difficulties—Variables, Data, and Information Much of this discussion has pivoted on information—information in a data set, information content of various scales, and transforming ... their limited data capacity and inability to handle certain types of operations needed in data preparation, data surveying, and data modeling. For exploring small data sets, a...

Ngày tải lên: 24/10/2013, 19:15

... execution data is in its “raw” form, and the model works only with prepared data, it is necessary to transform the execution data in the same way that the training and test data were transformed. ... Accessing the data 2. Auditing the data 3. Enhancing and enriching the data 4. Looking for sampling bias 5. Determining data structure 6. Building the PIE 7. Surveying the data...

Ngày tải lên: 24/10/2013, 19:15

... original data set. The data preparation software creates this variable and captures information about the missing value patterns. For each pattern of missing values in the data set, the data preparation ... where the data comes from, what is in the data, and what issues remain to be established—in other words, to determine the general quality of the data. This forms the f...

Ngày tải lên: 29/10/2013, 02:15

... the original data sample. Random sampling does that. If the original data set represents a biased sample, that is evaluated partly in the data assay (Chapter 4), again when the data set itself ... what a data miner starts with as a source data set is almost always a sample and not the population. When preparing variables, we cannot be sure that the original data is bias free...

Ngày tải lên: 29/10/2013, 02:15

... include such features as creating a pseudo-variable for “North,” one for “South,” another for “East,” one for “West,” and perhaps others for other features of interest, such as population density ... of pseudo-variable inputs for each alpha label—that is, for this example, a unique pattern for each item in the produce department. The domain expert must make sure, for exam...

Ngày tải lên: 08/11/2013, 02:15

... Translating the information discovered there into insights about the data, and the objects the data represents, forms an important part of the data survey in addition to its use in data preparation. ... putting data into the multitable structures called “normal form” in a database, data warehouse, or other data repository.) During the process of manipulation, as well as expo...

Ngày tải lên: 08/11/2013, 02:15

... Third, and very important for maximum information exposure, the individual variable distributions are transformed. This transformation makes the between-variable information far more accessible ... least harm to the information content of the data set. Yet it still leaves some information exposed for the mining tools to use when values outside those within the sample data set are...

Ngày tải lên: 08/11/2013, 02:15

... Series Data Series data differs from the forms of data so far discussed mainly in the way in which the data enfolds the information. The main difference is that the ordering of the data ... Preparing series data for modeling, then, must preserve the nature of the pattern that exists. Preparation also includes putting the data into a form in which the desired inform...

Ngày tải lên: 15/12/2013, 13:15

... extracting information from noisy or distorted series data. They have involved extracting a variety of waveforms from the original waveform that emphasize particular aspects of the data useful for modeling. ... transform accomplishes this. The second transform subtracts the mean of the transformed variable from each transformed value, and divides the result by the standard deviation....

Ngày tải lên: 15/12/2013, 13:15

... of the survey, rather than data preparation? Data preparation concentrates on transforming and adjusting variables’ values to ensure maximum information exposure. Data surveying concentrates ... density manifold stability. But here is where data preparation steps into the data survey. The data survey (Chapter 11) examines the data set as a whole from many differe...

Ngày tải lên: 15/12/2013, 13:15