According to Ausubel (1968), prior or existing knowledge is of major importance for a learner to acquire new conceptual knowledge meaningfully through hierarchical structure of concepts and preposition.

Thus, meaningful learning is obtained from networking of facts when the new learning fits into an existing concept which is learnt through connection for easy understanding and retention.

Concept Mapping

Similarly, Novak (1998) stated that concept mapping is the theory of meaningful learning when new information is incorporated into an existing concept and undergoes changes and growth in the learner. It is a useful structure for negotiating ideas through brainstorming to stimulate learners to relate the new information to the previous knowledge.

This structure integrates new learning into prior ideas that a learner has developed through mental images, and created by words or thoughts which help the learner focus on a topic in a lesson.

It is a representation that enables learners to organize, relate, and explain concepts explicitly or implicitly and represents relationships between the main and related ideas denoted in levels of abstraction where the main idea is placed at the top and related ideas placed at the bottom.

Ausubel as a constructivist, therefore indicates that learning takes place when learners make connections between and/or among ideas throughout their personal learning (Dunaway, 2011). As a constructivist-related process of connecting information, meaningful learning consequently rests in diversity of opinions by the learners to develop and maintain these connections to facilitate continuous understanding of concepts.

Additionally, Siemens (2004) relates this principle to constructivist theory as the knowledge that emerges from an individual's learning network when connections are made between or among concepts enabling the learner to construct his or her own understanding of concepts.

To this end, Ausubel learning theory suggests that effective instruction requires the teacher to choose relevant instructional strategies to teach and provide the means to help learners relate new information to concepts they already possess.

In this instance, the teacher makes teaching and learning meaningful when the background and interest of the learner is known. The teacher therefore develops strategies to help the learner to assimilate and accommodate the new information during the learning process to allow learners to bring on board ideas through debates and discussions for deep understanding of concepts.

This support for learners by the teacher is done through scaffolding and mediation in which the learner does most of the activities during the learning process and the teacher acts as the facilitator to reinforce the new learning.

Scaffolding

Scaffolding refers to the use of variety of instructional techniques aimed at moving learners progressively towards stronger understanding and ultimately to greater independence in the learning process.

In this case, the teacher breaks up the learning tasks into smaller parts and then provides learners with the support they need through their experiences to learn the concept in parts. Ausubel therefore maintained this position of meaningful learning very clearly when he stated that:

'If I had to reduce all educational psychology to just one principle, I would say this: The most important single factor influencing learning is what the learner already knows. Ascertain this and teach him/her accordingly'.

This is explained when the teacher considers what the learner already knows which as a matter of importance must be incorporated in lesson plans. Therefore, teachers must not always think that they are the repository of knowledge where they take full responsibility of what the learner needed to learn, when it is to be learned, and how the knowledge and skills are to be acquired.

This strategy renders the learner active and promotes their growth and development as they learn through their experiences. Through the various acquired by the learners, they interact among with the curriculum among themselves as they take part in their own learning.

There are three requirements in Ausubel theory that is relevant to knowledge acquisition. The first is that learners build mental pictures of what they already know to match them to the new information in which concepts are analyzed at different stages.

Relevant Learning

The second is the relevant learning material which learners use to construct significant concepts and the plans that are related to the knowledge to be obtained. Lastly, the learner must choose to learn meaningfully through conscious and deliberate means and relate the new knowledge to the existing knowledge.

Accordingly, advance organizer classifies the aim of a lesson that relates to the students' knowledge by logically organizing the learning material to engage the students in learning activities which strengthens their cognitive understanding for knowledge retention.

An advance organizer is a reasoning strategy that provides learning framework and presented before learning takes place to help learners organize and interpret new information.

Distinguishing between meaningful and rote learning, Ausubel (1968) indicates that meaningful learning takes place when information is broken into parts for understanding since there is a relationship between the new and previously acquired knowledge.

Rote Learning

On the contrary, rote learning happens when information are wholly memorized without breaking them into parts or relating them to prior knowledge. In this instance, new information is not retained for a long period because it is random, discrete, verbatim and non-substantive and cannot be integrated into any new or previous ideas for intellectual understanding, hence providing difficulties in showing patterns of recall.

On the other hand, when learners learn meaningfully, they retain the information much longer because there is a relationship between the new and previously acquired knowledge.

In this learning, the cognitive structure is clear and facilitates the retention of new content. Consequently, information which learners learnt meaningfully is applied in a variety of ways to solve unfamiliar problems through knowledge transfer.

In doing so, this new information is cognitively fitted into a larger pattern with the learner having relevant ideas or appropriate concept that relates to what he already knows. Source: Ghana News Agency