Pilot Studies: On the Path to Solid Evidence

07/27/2017 08:19 am ET

This week, the Education Technology Industry Network (ETIN), a division of the Software & Information Industry Association (SIIA), released an updated guide to research methods, authored by a team at Empirical Education Inc. The guide is primarily intended to help software companies understand what is required for studies to meet current standards of evidence.

In government and among methodologists and well-funded researchers, there is general agreement about the kind of evidence needed to establish the effectiveness of an education program intended for broad dissemination. To meet its top rating (“meets standards without reservations”) the What Works Clearinghouse (WWC) requires an experiment in which schools, classes, or students are assigned at random to experimental or control groups, and it has a second category (“meets standards with reservations”) for matched studies.

These WWC categories more or less correspond to the Every Student Succeeds Act (ESSA) evidence standards (“strong” and “moderate” evidence of effectiveness, respectively), and ESSA adds a third category, “promising,” for correlational studies. Our own Evidence for ESSA website follows the ESSA guidelines, of course. The SIIA guidelines explain all of this.

Despite the overall consensus about the top levels of evidence, the problem is that doing studies that meet these requirements is expensive and time-consuming. Software developers, especially small ones with limited capital, often do not have the resources or the patience to do such studies. Any organization that has developed something new may not want to invest substantial resources into large-scale evaluations until they have some indication that the program is likely to show well in a larger, longer, and better-designed evaluation. There is a path to high-quality evaluations, starting with pilot studies.

The SIIA Guide usefully discusses this problem, but I want to add some further thoughts on what to do when you can’t afford a large randomized study.

1. Design useful pilot studies. Evaluators need to make a clear distinction between full-scale evaluations, intended to meet WWC or ESSA standards, and pilot studies (the SIIA Guidelines call these “formative studies”), which are just meant for internal use, both to assess the strengths or weaknesses of the program and to give an early indicator of whether or not a program is ready for full-scale evaluation. The pilot study should be a miniature version of the large study. But whatever its findings, it should not be used in publicity. Results of pilot studies are important, but by definition a pilot study is not ready for prime time.

An early pilot study may be just a qualitative study, in which developers and others might observe classes, interview teachers, and examine computer-generated data on a limited scale. The problem in pilot studies is at the next level, when developers want an early indication of effects on achievement, but are not ready for a study likely to meet WWC or ESSA standards.

2. Worry about bias, not power. Small, inexpensive studies pose two types of problems. One is the possibility of bias, discussed in the next section. The other is lack of power, mostly meaning having a large enough sample to determine that a potentially meaningful program impact is statistically significant, or unlikely to have happened by chance. To understand this, imagine that your favorite baseball team adopts a new strategy. After the first ten games, the team is doing better than it did last year, in comparison to other teams, but this could have happened by chance. After 100 games? Now the results are getting interesting. If 10 teams all adopt the strategy next year and they all see improvements on average? Now you’re headed toward proof.

During the pilot process, evaluators might compare multiple classes or multiple schools, perhaps assigned at random to experimental and control groups. There may not be enough classes or schools for statistical significance yet, but if the mini-study avoids bias, the results will at least be in the ballpark (so to speak).

3. Avoid bias. A small experiment can be fine as a pilot study, but every effort should be made to avoid bias. Otherwise, the pilot study will give a result far more positive than the full-scale study will, defeating the purpose of doing a pilot.

Examples of common sources of biases in smaller studies are as follows.

a. Use of measures made by developers or researchers. These measures typically produce greatly inflated impacts.

b. Implementation of gold-plated versions of the program. . In small pilot studies, evaluations often implement versions of the program that could never be replicated. Examples include providing additional staff time that could not be repeated at scale.

c. Inclusion of highly motivated teachers or students in the experimental group, which gets the program, but not the control group. For example, matched studies of technology often exclude teachers who did not implement “enough” of the program. The problem is that the full-scale experiment (and real life) include all kinds of teachers, so excluding teachers who could not or did not want to engage with technology overstates the likely impact at scale in ordinary schools. Even worse, excluding students who did not use the technology enough may bias the study toward more capable students.

d. Learn from pilots. Evaluators, developers, and disseminators should learn as much as possible from pilots. Observations, interviews, focus groups, and other informal means should be used to understand what is working and what is not, so when the program is evaluated at scale, it is at its best.

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As evidence becomes more and more important, publishers and software developers will increasingly be called upon to prove that their products are effective. However, no program should have its first evaluation be a 50-school randomized experiment. Such studies are indeed the “gold standard,” but jumping from a two-class pilot to a 50-school experiment is a way to guarantee failure. Software developers and publishers should follow a path that leads to a top-tier evaluation, and learn along the way how to ensure that their programs and evaluations will produce positive outcomes for students at the end of the process.

This blog is sponsored by the Laura and John Arnold Foundation

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