Boosting preschoolers’ literacy can be as simple as sending their parents a few texts – but it’s important not to overdo it.

That was the key finding of a recent study we conducted of a text-messaging program developed at Stanford University that is meant to improve parental engagement. We, Kalena E. Cortes and Hans Fricke – together with our co-authors Susanna Loeb and David Song – are interested in the best ways to improve children’s academic performance.

Through the program we studied, parents get three types of text messages: facts, tips and growth text messages.

Facts include general information about important literacy skills and parent-child activities, such as, “Children need to know letters to learn how to read & write. Research shows that kids with good letter knowledge become good readers.”

Tips include actionable advice with specific examples of parent-child literacy activities, such as, “Point out the first letter in your child’s name in magazines, on signs & at the store. Have your child try. Make it a game. Who can find the most?”

Growth messages provide continuous encouragement to parents of preschoolers throughout the school year: “Keep pointing out letters. You’re preparing your child 4K! (for kindergarten) Point out each of the letters in your child’s name. Ask: What sound does it make?”

Discovering what works

For our study, we wanted to know why the text-message program works and how to make it more effective. More specifically, we wanted to know if the advice being provided through the program was working and whether more text message tips would make the program even stronger.

To do this, we carried out a randomized experiment with 3,473 parents of preschoolers in a large urban school district in Texas. Four out of 5 of the preschoolers in our study came from families that are considered poor. Sixty-seven percent of the preschoolers are Hispanic and 28 percent are black.

We divided the parents of preschoolers into three different groups. The first group only got one text tip per week – on Wednesdays. The second group got the same thing as the first group, plus a fact message on Monday and a growth message on Friday. The third group got a text message five days a week. More specifically, this last group got a fact message on Mondays, a tip message on Tuesdays, Wednesdays and Thursdays, and a growth message on Fridays.

Three is the magic number for engagement

What we ultimately found is that three is the magic number for parent engagement. One tip is not enough and five text messages is too many. We found that parents who got one tip reported to engage less often with their children than parents with three text messages, but that five text messages were more likely to lead parents to opt out of the program. That is, parents who got five messages opted out at a rate of 8 percent, while parents who only got three texts opted out at a rate of 5 percent.

We also found that the effectiveness of the program to improve children’s literacy development, measured in 1-on-1 assessments, depends on how strong a preschooler’s literacy skills were in the first place. If children were lower performing, the single text message was not enough and in fact their literacy strength dropped compared to children whose parents received three texts. For instance, when children were asked to identify whether or not a word pair rhymes, lower performing children in the single-message program identified, on average, 0.6 out of nine word pairs less than those in the three-message program.

But those who were higher performing increased more in the single-message program – the one that offered just a tip – than in the three-message program, which included a fact, tip and growth message. As an example, the higher-performing children in the single-message program named around one common object more in one minute than those in the three-message program. The five-message program made no difference compared to the three-text program.

The bottom line is that for a text message program to work for parents, it pays to pay attention to what kind of messages are being sent and how often they are being sent. Parents of lower-performing children may benefit more from general information and encouragement, whereas parents of higher-performing children may only need tips on specific activities.

Whatever the case may be, the beautiful thing about this kind of text-message program is that it only costs about $2 a year per family to implement. And any parent with a cell phone can sign up for it for free.

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.