meaning and form between synonymy may help to facilitate vocabulary acquisition” (Webb, 2007, p. 126). Besides, students are unlikely to learn synonyms together, because they may lack the motivation to learn two new words that convey similar information. Confirming this idea, Rudzka et al. (1985) noted that intra lingual semantic relations give precise information about meaning and use in an economical and learnable way. Learning the synonyms of known words may be faster, because learners may gain large amount of L2 vocabulary knowledge from known synonyms. In fact, a transfer of L2 knowledge of known words to their synonyms can facilitate the use and understanding of synonyms.
Along similar lines, Nation (2001) proposed the term “learning burden” to suggest that learning a synonym for a word that is already known is a helpful practice. According to Nation, the general principle of “learning burden” is that the more a word represent patterns and knowledge that learners are already familiar with, the lighter its learning burden. These patterns and knowledge can be from L1, from knowledge of other languages and from previous knowledge of L2. This position has been advocated by psycholinguistics too.
Psycho linguistically, the association of words helps us to remember them (Mackey &Mountford, 1978). If a newly learned word can be substituted in a sentence for known synonym, then different aspects of its use will be acquired when meaning and form are learned. However, the degree of overlap of vocabulary knowledge varies from synonymy to synonymy (Webb, 2007). Nielsen (2006) presented the words in pairs that were close in meaning, but had subtle differences and hoped that the knowledge of these differences will enable the learners to learn words more effectively.
As learners’ vocabulary increases, the number of synonyms for known words increases too, because more and more words are likely to have synonymies. Thus, vocabulary achievement would be affected by the amount of prior knowledge. If learning synonymy for known words is easier than learning a word without synonymy, it explains how some L2 learners can incidentally learn a large number of words in later stages of L2 learning (Webb, 2007). Understanding the impact of synonymy on vocabulary achievement will be very helpful to teachers and learners, because this knowledge allows them to develop more efficient vocabulary teaching and learning strategies.
2.1.9. The effect of exemplification on vocabulary achievement
Besides synonymy, another widely used verbal technique is the exemplification. Students use the examples that are provided by the teachers as a major part of their learning. They use examples to understand language, to recall what they have memorized, to review what they are trying to learn, and to use new vocabulary in their communication. Examples are also sources of information. They can give the students information and insights into whatever topic they cover. Examples are important to students for understanding abstractions about English syntax and new vocabulary items and other aspects of language (Pigada& Schmitt, 2006). While selecting and using examples is one of the most important tasks of EFL/ESL teacher, little has been written about this issue in EFL/ESL classroom instruction. Exemplification is a basic communication strategy used in the negotiation of meaning in many different contexts, in both spoken and written language. Hirsh & Nation (1992), made an important point about the nature of exemplification as part of the communication process. They stated that all acts of communication can be viewed both as being the thing itself (e.g. a poem) and at the same time as being an example of the thing (e.g. a particular genre). It is a process through which meaning is clarified by the use of linguistic forms called examples. Examples can refer to a single word or sentence used to illustrate grammar rules or new vocabulary items.
However, their use is not limited to these contexts. They can be exploited in other aspects of language use. In reading and writing classes, teachers provide examples of the ways that discourse unit’s function, and in oral communication classrooms, examples are provided of the ways in which conversations are begun, conducted, and concluded. In vocabulary teaching classrooms, new vocabulary items can be dealt with through exemplification (Hirsh & Nation, 1992). By putting a new word in an example, different aspects of the word (e.g. collocates) will be revealed. It is especially a common procedure to illustrate the meanings of super ordinates, such as “furniture” “vegetable” by exemplifying them e.g. table, carrot, etc. There is no need to mention that the examples used to negotiate different aspects of language should be “good examples”. They should not be inaccurate and confusing. According to Pigada& Schmitt (2006), good examples are accurate, clear, attractive and transferable. In addition, Hirsh & Nation (1992, pp.130-133) present these characteristics of good examples:
1. They illustrate or confirm the item clearly. They are unambiguous.
2. They are understandable without more contexts.
3. They are as concrete as possible; the more concrete the better, especially in presenting words and vocabulary for beginners.
4. They do not contain difficult or rare vocabulary or irregular forms that are not involved in the particular item being illustrated.
Good examples can be powerful tools for language teachers and language learners. They are used by instructors to motivate students and explain and practice the item. Attention needs to be paid to the ways in which classroom teachers can use the examples in the presentation and practice of ESL. Further thought needs to be given to how ESL teachers can use examples for different purposes. Finally, we also need detailed information about ways in which skillful language learners use examples as part of learning skills so that we can incorporate these examples in course curriculum as an efficient practice.
2.1.10. The effect of visual aids on vocabulary achievement
It is said that a picture is worth thousands words. Images such as photographs capture reality in ways impossible even using the thousand words (Paivio, 1971). We, humans are highly visual creatures and surprisingly proficient at understanding images. Indeed, written communication in English would be impossible if we could not reliably distinguish between large amounts of symbols in the English alphabet. Corder (1977) noted that although information is normally imparted by language, large amount of conceptualized information is transferred to the learner by other means such as pictures, maps, charts, etc. Widdowson (1983) corroborated this idea suggesting that visual devices interact with the verbal part of the text to clarify ambiguity and thus enhance understanding. Since visuals are interest-getting and draw students’ attention they are efficient devices in interpreting and recalling materials. McDonough (1984) asserted that visual devices are not integrated with textual information and act only as an accompaniment to a stretch of language and aim to simply present additional information to the learner. The information provided by visuals serves as an aid for comprehension, retention. It functions as supplemental and supportive to verbal cues. Celce-Murcia (1991) found that foreign words associated with images or actual objects are learned more easily than those without such additional information. In a critical analysis of L2 vocabulary teaching techniques, Oxford and Crookall (1990) stated that most learners are capable of associating new information to concepts in memory by means of meaningful visual imagery that makes learning more efficient. With regard to the process of visual interpretation, Chandler &Sweller (1991) found that pictures demonstrated deeper processing than did verbal translation; because students had to figure out the meaning which they did not have to do if they saw the translati
on immediately. Quantitative results confirmed their beliefs; students who accessed pictorial cues demonstrated greater vocabulary learning than those who did not have access to visual aids. Visual imagery helps learners organize information more efficiently than they could if using words alone. Al-Seghayer (2001) stated that we remember images better than words; hence we remember words better if they are associated with images. He concluded that the pictorial/verbal combination involves many parts of the brain and provides greater cognitive power. There are some studies that address the question of long term recall. These studies (Anglin, 1986; Peng& Levin, 1979) show that not only does the presence of visuals with verbal cues aid in recall, but also those effects endure over time. There are scientific rationales behind this statement. In an effort to explain the efficient recall of pictures, the theory of “dual coding” was proposed by Paivio (1971; 1986). He asserted that there are two types of memory coding: in a verbal system and in imaginal system.
Verbally presented material is encoded only in verbal system, while visually presented material is encoded in visual system. So, pictures have dual coding in two types of memory codes; if these two codes provide more cues for recall, then it will be easier to remember pictures.
Despite the considerable amount of research concerning how static visuals facilitate learning, there is not a consensus among researchers about the manner in which visuals function in facilitating learning. A number of researchers have provided a variety of functional frameworks. Liu & Reed (1994) identified three general functional roles of visuals in text: (a) an intentional role, (b) a retention role, and (c) an explicative role. The intentional role relies on the fact that pictures naturally attract attention. The retention role aids the learner in recalling information seen in the visuals, and the explicative role explains, in visual terms, information that would be hard to convey in verbal or written terms. An alternative functional framework offered by Gu& Johnson (1996) suggests that a functional framework includes classifying visuals in text based on how they influence a learner in attending, feeling, or thinking about the information being presented. Their framework contains four major functions: (a) attention, (b) affective,(c)
cognitive, and (d) compensatory. The attention function attracts or directs attention to the material. The affective function enhances enjoyment or, in some other way, affects emotions and attitude. Visuals serving a cognitive function facilitate learning text content through improving comprehension, improving retention, or providing additional information. The last functional role identified by Gu& Johnson, is the compensatory role, which is used to accommodate poor learners. The other framework was proposed by Alesandrini (1981) which classifies the role of instructional pictures into three functions: (a) representational, (b) analogical, and (c) arbitrary.He stated that Representational pictures can convey information in a direct way through tangible objects or concepts or indirectly by the use of intangible concepts that have no physical existence. Photos and drawings, or models are examples of representational visuals. Analogical pictures convey meaning by acting as a substitute and then implying a similarity for the concept or topic which is presented. Arbitrary pictures (sometimes referred to as logical pictures) are highly schematized visuals that do not look like the things they represent but are related in some conceptual or logical way. Arbitrary illustrations include schematized charts and diagrams, flowcharts, tree diagrams, maps, and networks.
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