OK, but isn’t the term “fadeout” too negative for what is really going on most of the time? In the case of, say, a pre-K intervention, kids who received the program and kids who did not receive the program keep learning after the program ends. The kids who received the program don’t actually forget what they learned during pre-K (for example, they don’t forget how to identify letters or count). Instead, the kids who did not receive the program eventually catch up. So, isn’t “catch-up” a better term? And isn’t “catch-up” a good and equitable result, since the lower-achieving kids who did not attend pre-K eventually learn more?
This is a common perspective among early-childhood-education researchers. We think that the line of reasoning that reframes fadeout as socially desirable “catch-up” is misleading and obscures what is really going on.
The easiest way to understand the issue is to imagine a randomized controlled trial in which children are randomly assigned to either an education intervention or a control group. As any basic research methods textbook argues, a randomized controlled trial produces a control group that can be understood as an approximation of the counterfactual condition. In other words, the outcome for the control group is what we would have observed for the treatment group had the treatment not been administered. So, if we observe children’s learning two years after a given intervention, and the control group has “caught up” to the learning levels of the treatment group, we should understand this to mean that the treatment group now has the same level of skills that they would have had if the intervention had never been administered.
If we want education interventions to have long-lasting effects for socially progressive reasons (for example, closing achievement gaps related to socioeconomic status), control group children “catching up” is not desirable. In the context of many education interventions that are targeted toward children at risk for underachievement compared with some other group (for example, poor versus non-poor children; children who are struggling to read versus children who are reading at grade level), “catch-up” implies that both groups are now lagging behind their higher-achieving peers. Indeed, both groups of children are at the same level as before the intervention started—which is presumably the problem that motivated the intervention in the first place.
The term “fadeout” is most often associated with research on early childhood interventions, but in fact the fadeout phenomenon occurs far more generally. Researchers have also observed fadeout in studies of adults, where members of the control group would not be expected to demonstrate gains in the targeted skills. Tailoring our definitions and explanations of fadeout too closely to early childhood contexts risks missing important insights into why it happens and its policy implications.
