Eight Buying Tips: Data Warehouses

Many schools, districts, and states have responded to No Child Left Behind by implementing data management systems, including data warehouses, to help them efficiently organize and analyze the enormous amount of student and school performance data they generate each year.

According to the November 2003 Eduventures report, Making Sense of the Data, the market for data management and analysis systems has grown to $145 million and will continue to expand each year. As the industry has grown, so has the number of vendors providing data warehousing tools and services. In fact, there are now more than 20 vendors serving this market, some with more than 10 years of experience and others just signing up their first customers. This expansion benefits school and district leaders in that it provides additional options and creates increased competition. On the downside, it makes selecting the right solution that much more challenging.

Whether you're buying an off-the-shelf data warehouse or intend to build your own, the following questions will guide you through the critical process of selecting a product or finalizing a product design.

1. Does the solution integrate the information systems you want to explore?

A good data warehousing solution will allow you to integrate data from any source, whether it's your district-wide student information system or informal databases housed on spreadsheets. Accordingly, look for providers with specific experience integrating data from student information, assessment management, special education, human resources, and finance systems, as well as data from Microsoft Excel, Microsoft Access, comma-separated values, field-length flat files, and tab-delimited formats. You'll also want a solution that allows for unlimited longitudinal data.

Some data warehousing vendors have established strategic partnerships with student information system vendors. These alliances allow the warehousing vendors to develop better tools for data extraction and cleansing (sometimes called ETL for Extract Transform and Load). When selecting a product, ask your vendors to describe their partnerships and provide references for successful projects.

2. Does the data model fit your needs?

The goal of a data warehouse is to allow users to explore relationships between information bits that were previously disconnected. How does classroom attendance relate to performance on standardized tests? What's the link between professional development and course grades? How you'll be analyzing these connections and others will depend greatly on the type of database technology being used.

Many data warehouses, for example, are built around predefined multidimensional data cubes. In this design, the vendor builds an optimized database using a limited number of commonly used data elements such as demographics and test scores. The result is a highly efficient system with extremely fast response times as users navigate through the optimized dimensions of the cube. (The software used to analyze data cubes is known as online analytical processing tools.)

A less efficient, but far more robust, alternative to cube-based solutions are relational database management systems. Most conventional databases employ a RDBMS structure where each data element is stored only once and is connected to every other data element. This allows users to develop ad hoc queries to analyze any data in the system. Data is not consolidated or optimized to improve search efficiency, but all details of all data elements are available for exploration and analysis.

3. What data domains are supported?

Every piece of information collected by a school that relates to an individual student's performance should be available for analysis. Look for solutions that, at a minimum, include the following data domains:

  • Student demographics
  • School and course enrollment
  • Course and instructor attributes
  • Student attendance
  • Standardized assessment results
  • Course grades
  • Special education status, plans, services, and events
  • English proficiency
  • Discipline referrals
  • Extracurricular involvement
  • Transportation, food service, and medical
  • Staff demographics, attendance, and professional development
  • Program tracking and evaluation
  • Budgets by account, department, and location.
  • Integration tools for your key student information systems, including informal databases held in spreadsheets
  • Easy-to-use tools for conducting online analytical processing or building ad hoc queries
  • Comprehensive data extraction and cleansing tools
  • Support for all of the data domains you wish to analyze, including support for longitudinal capture and reporting
  • Multilayer security, including firewall, SSL, certificates, and encryption
  • Rapid turnaround of data updates
  • Ample professional development training services and technical support