Transcript download1 - Courses - University of California, Berkeley

Data Mining and the Weka Toolkit
University of California, Berkeley
School of Information
IS 257: Database Management
IS 257 – Fall 2008
2008.11.13- SLIDE 1
Lecture Outline
• Review
– Data Warehouses
• (Based on lecture notes from Joachim Hammer,
University of Florida, and Joe Hellerstein and Mike
Stonebraker of UCB)
• Applications for Data Warehouses
– Decision Support Systems (DSS)
– OLAP (ROLAP, MOLAP)
– Data Mining
• Thanks again to lecture notes from Joachim
Hammer of the University of Florida
IS 257 – Fall 2008
2008.11.13- SLIDE 2
Knowledge Discovery in Data (KDD)
• Knowledge Discovery in Data is the nontrivial process of identifying
– valid
– novel
– potentially useful
– and ultimately understandable patterns in
data.
• from Advances in Knowledge Discovery and Data
Mining, Fayyad, Piatetsky-Shapiro, Smyth, and
Uthurusamy, (Chapter 1), AAAI/MIT Press 1996
Source: Gregory Piatetsky-Shapiro
IS 257 – Fall 2008
2008.11.13- SLIDE 3
Related Fields
Machine
Learning
Visualization
Data Mining and
Knowledge Discovery
Statistics
Databases
Source: Gregory Piatetsky-Shapiro
IS 257 – Fall 2008
2008.11.13- SLIDE 4
Knowledge Discovery Process
Integration
Interpretation
& Evaluation
Knowledge
Knowledge
__ __ __
__ __ __
__ __ __
DATA
Ware
house
Transformed
Data
Target
Data
Patterns
and
Rules
Understanding
Raw
Dat
a
Source: Gregory Piatetsky-Shapiro
IS 257 – Fall 2008
2008.11.13- SLIDE 5
OLAP
• Online Line Analytical Processing
– Intended to provide multidimensional views of
the data
– I.e., the “Data Cube”
– The PivotTables in MS Excel are examples of
OLAP tools
IS 257 – Fall 2008
2008.11.13- SLIDE 6
Data Cube
IS 257 – Fall 2008
2008.11.13- SLIDE 7
Phases in the DM Process: CRISP-DM
Source: Laura Squier
IS 257 – Fall 2008
2008.11.13- SLIDE 8
Phases and Tasks
Business
Understanding
Determine
Business Objectives
Background
Business Objectives
Business Success
Criteria
Situation Assessment
Inventory of Resources
Requirements,
Assumptions, and
Constraints
Risks and Contingencies
Terminology
Costs and Benefits
Data
Understanding
Collect Initial Data
Initial Data Collection
Report
Data
Preparation
Data Set
Data Set Description
Select Data
Data Description Report
Rationale for Inclusion /
Exclusion
Explore Data
Clean Data
Describe Data
Data Exploration Report
Verify Data Quality
Data Quality Report
Determine
Data Mining Goal
Data Mining Goals
Data Mining Success
Criteria
Data Cleaning Report
Construct Data
Derived Attributes
Generated Records
Integrate Data
Merged Data
Format Data
Modeling
Select Modeling
Technique
Modeling Technique
Modeling Assumptions
Generate Test Design
Test Design
Build Model
Parameter Settings
Models
Model Description
Assess Model
Model Assessment
Revised Parameter
Settings
Evaluation
Evaluate Results
Assessment of Data
Mining Results w.r.t.
Business Success
Criteria
Approved Models
Review Process
Review of Process
Determine Next Steps
List of Possible Actions
Decision
Deployment
Plan Deployment
Deployment Plan
Plan Monitoring and
Maintenance
Monitoring and
Maintenance Plan
Produce Final Report
Final Report
Final Presentation
Review Project
Experience
Documentation
Reformatted Data
Produce Project Plan
Project Plan
Initial Asessment of
Tools and Techniques
Source: Laura Squier
IS 257 – Fall 2008
2008.11.13- SLIDE 9
Phases in CRISP
•
Business Understanding
–
•
Data Understanding
–
•
In this phase, various modeling techniques are selected and applied, and their parameters are calibrated to optimal values.
Typically, there are several techniques for the same data mining problem type. Some techniques have specific requirements on
the form of data. Therefore, stepping back to the data preparation phase is often needed.
Evaluation
–
•
The data preparation phase covers all activities to construct the final dataset (data that will be fed into the modeling tool(s)) from
the initial raw data. Data preparation tasks are likely to be performed multiple times, and not in any prescribed order. Tasks include
table, record, and attribute selection as well as transformation and cleaning of data for modeling tools.
Modeling
–
•
The data understanding phase starts with an initial data collection and proceeds with activities in order to get familiar with the data,
to identify data quality problems, to discover first insights into the data, or to detect interesting subsets to form hypotheses for
hidden information.
Data Preparation
–
•
This initial phase focuses on understanding the project objectives and requirements from a business perspective, and then
converting this knowledge into a data mining problem definition, and a preliminary plan designed to achieve the objectives.
At this stage in the project you have built a model (or models) that appears to have high quality, from a data analysis perspective.
Before proceeding to final deployment of the model, it is important to more thoroughly evaluate the model, and review the steps
executed to construct the model, to be certain it properly achieves the business objectives. A key objective is to determine if there
is some important business issue that has not been sufficiently considered. At the end of this phase, a decision on the use of the
data mining results should be reached.
Deployment
–
Creation of the model is generally not the end of the project. Even if the purpose of the model is to increase knowledge of the data,
the knowledge gained will need to be organized and presented in a way that the customer can use it. Depending on the
requirements, the deployment phase can be as simple as generating a report or as complex as implementing a repeatable data
mining process. In many cases it will be the customer, not the data analyst, who will carry out the deployment steps. However,
even if the analyst will not carry out the deployment effort it is important for the customer to understand up front what actions will
need to be carried out in order to actually make use of the created models.
IS 257 – Fall 2008
2008.11.13- SLIDE 10
The Hype Curve for
Data Mining and Knowledge Discovery
Over-inflated
expectations
Growing acceptance
and mainstreaming
rising
expectations
Performance
Disappointment
Expectations
1990
1998
2000
2002
Source: Gregory Piatetsky-Shapiro
IS 257 – Fall 2008
2008.11.13- SLIDE 11
More on Data Mining using Weka
• Slides from Eibe Frank, Waikato Univ. NZ
IS 257 – Fall 2008
2008.11.13- SLIDE 12