By CELA on 18 Feb, 2019

The word gap

Hands up who knows about the 30 million word gap?

You probably learned it in your diploma or degree as an article of faith in research terms, or maybe you’ve read about it since in a journal article or heard it at a conference. The concept is so well accepted that you may even have seen it in newspaper stories or on television news.

The gap we refer to is the 30 million words less that children in disadvantaged homes will hear before they turn three years old.

Or will they?

Looking back

When the 30 million word gap research was first published in 1992 it was the culmination of a 1200 hours of family audio recordings begun in 1982. The two researchers, Betty Hart and Todd Risley, had worked preschoolers in an earlier study and noted differences between the children from poorer families and those from more middle class families in their part of Kansas, USA. Seeing a pattern of difference as early as age three, Hart and Risley framed a study and visited the homes of babies aged from 7-9months old every month, for an hour, for two and a half years.

Being the 1980s, they were equipped with a cassette recorder, a clipboard and a stopwatch, and they recorded the number of words spoken around the children as well as attempting to code the quality and types of interactions, They also tracked the growth in the words produced by the children.

The study was based on 42 families at four levels of income and education.

Mind the gap

Their findings were also released in a book, Meaningful Differences in the Everyday Experience of Young American Children, in 1995. The book turned an academic paper into a powerful piece of social evidence, on which policies, programs and political platforms have been built. Bill Clinton is just one of the influential figures to use the research in laudable policy initiatives during his time as president.

But there’s a problem. Since that time, despite many attempts in many countries, no one has been able to replicate the catchy 30 million gap that Hart and Risley identified using their cassette tapes, stopwatches and clipboards.

A gap exists, there’s no doubt about that, but the real figure, based on modern technology and repeated academic studies, may be more like 4 million words, not 30 million.

Stop bugging me

If Hart and Risley were to start again today (both are deceased, so that’s not possible) they would possibly begin by whipping out their smart phones and opening up voice recording apps, storing their files in the cloud awaiting analysis by a sophisticated voice recognition program.

Other researchers have gone further, like the LENA 2017 study that used tiny listening devices attached to family members’ clothing. This wasn’t just showing off ‘bug’ technology. One of the criticisms now levelled at the 30 million word gap is that it suffered from a socio-economically driven ‘observer effect’.

That is, the families in the ‘welfare’ group may have felt judged or intimidated and spoken less because the researchers were there, while the families in the ‘professional’ group may have felt confident in their parenting and spoken more because they wanted to impress the researchers with their communication.

Does it matter?

The so-called Sperry report released last year called itself a ‘failed replication’ of the Hart and Risley 30 million word gap study. The latest in a line of other attempts to replicate the scale of the originally reported gap, the report is called Reexamining the Verbal Environments of Children From Different Socioeconomic Backgrounds. What the Sperry researchers found was:

Results do not support Hart and Risley’s claim, reveal substantial variation in vocabulary environments within each socioeconomic stratum, and suggest that definitions of verbal environments that exclude multiple caregivers and bystander talk disproportionately underestimate the number of words to which low‐income children are exposed.

In other words (pardon the pun) one of the major flaws in the first study is that it excluded ‘multiple caregivers and bystander talk’ – and that means educators like you, and your colleagues.

From the perspective of Australian educators under frequent fire from critics of higher quality early learning programs, you can take hold of another piece of evidence that your interactions with children matter greatly.

What have we learned?

For one thing, while the number may have changed, the gap still exists.The four (or seven, or 12) million fewer words heard by poorer children by the age of three or four remains a reason to push for universal access to affordable, high quality early childhood education. Social think tanks like the Brookings Institute say there’s a danger in accepting any one number as a ‘truth’ since all the research from Hart and Risley forward has found complexities in results between social, economic, and geographic areas.

Another thing the process of study and replications have shown is that inherent biases can’t be ignored. Some researchers have focused their attention on ‘word wealth’ and pointed out that the study only recorded English words. In Australia and elsewhere, many bilingual children may exhibit a smaller vocabulary range in their early years, but can describe most of the concepts and items in their vocabulary with a word from more than one language.

And finally, we’ve learned not to take for granted the things we may learn in our youths! All professional learning is lifelong, no matter how eternal the truth may seem at the moment you first heard it.



Meet the author


Bec Lloyd is the founder and managing director of Bec & Call Communication, providing professional writing, editing and strategy services to the school and early childhood education sector since 2014. In 2018 she launched UnYucky mindset and menus for happier family mealtimes. Formerly the communications lead at ACECQA and BOS (now NESA), Bec is a journo and mother of three who produces Amplify for us at Community Early Learning Australia.

About CELA

Community Early Learning Australia is a not for profit organisation with a focus on amplifying the value of early learning for every child across Australia - representing our members and uniting our sector as a force for quality education and care.

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