Bottom-up decoding: reading and listening for the future

Mark Bartram, a teacher trainer and materials writer, explores different approaches for processing written and spoken text, and how they can be integrated into the English language classroom. 

Are you a top-downer or a bottom-upper? The debate as to the relative importance of these two approaches to understanding spoken or written text has been going on for decades. Most people would agree that both approaches are useful at different times and for different reasons. In this blog I will attempt to explain why the bottom-up approach should not be neglected.

First, some definitions.

Top-down processing starts from the reader or listener. It assumes that the learner brings to the text certain knowledge – of the world, of texts (including how certain types of conversation typically unfold), and of language. This knowledge is likely to be useful in understanding a text (whether written or spoken), but it often needs to be activated, and activities such as discussions, questionnaires, quizzes, brainstorms, and vocabulary-anticipation can all be used to do this.

For example, when you saw the title of this piece, you probably started thinking about what it might mean, what the arguments in the piece were likely to be, whether you wanted to read it, and so on.

So assuming you still do want to read it…

Bottom-up processing starts from the text. It assumes that by working on a combination of different aspects of the written or spoken text, the learner can increase their ability to comprehend it. These might be very “micro-” elements, such as the fact that we tend to insert a “w” sound between certain vowels; or they could be at a more “macro-” level, such as searching for synonyms within a text. The key idea here is decoding.

For example, in order to understand the second sentence of this piece (the one that starts “The debate…”), you needed to work out that the first 17 words are the subject (a complex noun phrase), that the verb comes next (“has been going on”), followed by an adverbial (though unless you are a grammar geek, you won’t have used these terms). Identifying the verb is a key aspect of decoding complex texts.

Improving the ability to decode

Most people would agree that we use a combination of the two approaches when we are processing a text. We tend to switch from one to another as is needed. But whereas it used to be thought that we revert to bottom-up processing when we are unable to use top-down (for example, if we are unable to predict the content, we have to listen to the actual words!), research suggests that in fact the reverse is true. If you are in a noisy café, and can’t “decode” what your friend is saying (bottom-up), you tend to fill in the gaps with your knowledge of the world, or your friend’s usual speech habits.

Within this framework, the idea of “comprehending a text” needs to be defined. Many activities in coursebooks are essentially asking the learners: “Did you understand this text?” – i.e. the one in front of them. This can work as an assessment or diagnostic tool, but the danger is that it does not prepare the learners for the next text. In other words, we need to train learners in transferable skills that can be used for any text in the future.

We can do this to a limited extent with top-down activities – for example, we can train learners to use prediction techniques to anticipate the content and language of a text. Furthermore, classroom research and teacher experience tell us that top-down activities such as the ones listed above can be integrated easily into lessons, are motivating and fun, and enhance the overall experience for the learner. So we should not discount top-down activities entirely.

However, common sense tells us that we are often in situations where we are less able to use top-down skills, for example, in exams, or simply when we turn on the radio at random. At this point, our ability to decode becomes key. And it is with bottom-up approaches that the training aspect comes into its own.

Vocabulary, of course, is vital. The wider your vocabulary, the more fluent your reading or listening is likely to be. However, bottom-up skills remain important because they work on aspects of the text that are useful even when the learner’s vocabulary level is high. We have all heard learners say plaintively “Well, I know all these words, but I still didn’t get what they were saying!” For this reason, reading and listening activities need to include work on decoding text.

Subsequent blog articles will explore how training in bottom-up decoding can be introduced painlessly into the classroom.