Why Do We Need a Longitudinal Data System?

Why does the State of Illinois need a longitudinal data system? Or, to put it more precisely, how does longitudinal data help answer key policy questions?

To understand the answer, let’s examine a longitudinal question at the heart of EdSystems work: What paths do students take from high school into careers? This is a key question. By answering this question, we can better understand the coursework students should take and the support we can provide in both high school and postsecondary education. We can examine when it is valuable to get a four-year degree and when a two-year degree or certificate may suffice. We can save students and their families money and ensure that students have the wherewithal to succeed no matter what postsecondary paths they choose.

EdSystems is keen to get answers to these questions so that we can improve the policy development and implementation support we provide. Furthermore, we believe data and the Illinois Longitudinal Data System (ILDS) are a foundation for collaboration. At EdSystems, we can use data to determine where we are the most effective and where other partners make the most sense. In addition, we want to collaborate on research, including our colleagues at NIU and research partners such as the Illinois Workforce and Education Research Collaborative. The ILDS aims to build an environment where research builds off the work of those who have come before.

However, answering questions with longitudinal data often cuts across agencies and requires sharing data across those agencies, which is a challenging process. We need a longitudinal data system to do this work.

Making the Case for the ILDS: A Blog Series

In our first blog of the series, Marking Five Years of Progress: A Status Update for the Illinois Longitudinal Data System, we overviewed the recent ILDS 2.0 initiative and its accomplishments.

In the second entry, What Is in the ILDS? What Questions Can It Answer?, we discussed the policy questions that a longitudinal data system can answer.

In this entry, we address how longitudinal data help answer key policy questions and why sharing data across state agencies is critical.

Why Is It So Hard to Share Data?

EdSystems is vested in making the ILDS a success, but we believe that state agencies and other partners should also be excited about the ILDS. While state agencies are very careful about how they share data, they have shown significant interest in sharing data. Because state agency data is mostly about individuals, including children, we do not want this data in the wrong hands. However, we also want our government to be transparent about its services to ensure efficiency, effectiveness, and equity. It is a hard balancing act. Agencies know that making data available safely and securely is in everyone’s best interest.

Currently, the process for getting data is too hard. In our experience, most agencies would agree with this, especially when cross-agency data is requested. State agencies are some of the biggest users of cross-agency data, and even when working with each other, the process of sharing data can be challenging. This is because the data request, legal, and technical processes and requirements differ across agencies. While state agencies have internal relationships that can make things go faster, even these can be strained when there is a change in personnel and leadership.

Part of the reason the data-sharing process is so hard is that the requested data is often disaggregated, i.e., at the individual or student level. This is not data that can generally be shared through a Freedom of Information Act (FOIA) request or a report on a website. Rather, the data must be stripped of all personally identifiable information (PII) and anonymized before sharing so that it cannot be traced back to an actual person. Even then, it can only be shared in a secure environment, and there are strict rules about who can access it and what researchers can do with it.

Because longitudinal data often comes from multiple agencies, it requires working with multiple program, legal, and technical teams. The process can often take many months and sometimes even a year or two, as lawyers, technical teams, and program teams go back and forth, ensuring that all the correct procedures are followed.

Despite this, there are ways to make the process easier, and the ILDS team, staffed by EdSystems, and the state agencies are working on how to make that happen. The key is to streamline the process and standardize the approaches to requesting, sharing, and linking data. Critical to streamlining the process is having a centralized data management and analytics system where data can be accessed and managed and within which research can occur.

How the ILDS Streamlines the Process

In some ways, Illinois’ approach to streamlining access to data is similar to that of many other states. For example, states such as Florida and Kentucky have long used data warehouses to streamline data access. To create a data warehouse, agencies in other states often must generate data files and ship them to a central administrator. This means the data teams can provide access to internal stakeholders much more easily than in the past. But it has not solved all their problems. In a warehouse model, agencies lose control of their data, so usage must be restricted. External researchers and other analytics partners do not have direct access to the underlying system, which limits the value of this approach.

Illinois’ goal is more ambitious. The goal is to create a system that is valuable to state analysts and allows the state to collaborate with external research partners and other interested parties to do advanced analytics that allow us to better understand the cause and effect of different policies and interventions. Doing research of this type is non-trivial and requires detailed data and significant methodological expertise. The goal is to be as transparent as possible in a responsible, ethical, and equitable way.

By using a more modern technical architecture, we can make this happen. Illinois’ architecture ensures that agencies remain in control of their data from the time it is shared to the moment a report using the data is published. At any point, the agency can pull its data back – but perhaps more importantly, researchers and state agencies can collaborate to ensure the best data products possible. This ensures that data is handled and used appropriately. This doesn’t mean that data won’t shine a light when things are not working as they should be, but it does mean that when data highlights the need for improvement, we can be confident that the story it tells is valid. Illinois’ architecture also means that data requests, legal agreements, and matching processes can be standardized and streamlined. This should reduce processes that currently take months to weeks.

While the system is not yet complete, it is well on its way, with various pilot projects started. In the coming months, EdSystems looks forward to working with our state agencies to bring the ILDS to life.

In the next blog post of this series, we will revisit the accomplishments and start to outline the remaining challenges to complete the development of the ILDS.

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