Bottom-up and Top- down processing

Introduction:

Studies in reading comprehension and listening comprehension have distinguished between two kinds of processing used by skilled and less-skilled readers/listeners: Bottom-up and Top-down. In most situations, bottom-up and top-down processes work together to ensure the accurate and rapid processing of information. However, theories about the cognitive processes involved in reading and listening differ in the emphasis that they place on the two approaches.  These two processes seen as a style of thinking and teaching. In many cases, top-down is used as a synonym of analysis or decomposition, and bottom-up of synthesis.

Bottom-up processing

Bottom-up processes describe the ways in which the linguistic competence of a listener works to 'build' toward comprehension of a message. A listening process where listeners interpret incoming speech signals by learning skills that aid in decoding the speech patterns. These are the lower level processes that work to construct meaning from recognition of sounds and words, which, when identified, are fit into larger phrasal units and then matched with related ideas stored in long-term memory.

It happens when someone tries to understand language by looking at individual meanings or grammatical characteristics of the most basic units of the text, (e.g. sounds for a listening or word for a reading), and moves from these two trying to understand the whole text. Bottom-up processing is not thought to be a very efficient way to approach a text initially, and is often contrasted with top-down processing, which is thought to be more efficient. For example, Asking learners to read aloud may encourage bottom-up processing because they focus on word forms, not meaning.

 Top-down processing

Top-Down processes work in the opposite direction, drawing on the listener's own prior knowledge and expectations to help decode the message. The listener's repository of background information can relate to the context, the topic, the type of text, conventions of rhetoric and discourse organization. This knowledge becomes useful in decoding a message--even when a message has not heard in its entirety.

The learners use their prior knowledge to make predictions about the text. Teachers often think that the learners hear or read every sound, word or sentences before they understand the general meaning of the passage. However, in practice, they often adopt a top-down approach to predict the probable theme and then move to the bottom-up approach to check their understanding. The process of comprehension is guided by the idea that input is overlaid by the pre-existing knowledge in an attempt to find a match. In the case of top-down processing, the listeners must relate textual materials to their background knowledge.

Shared by: Aayesha Qureshi