2.1 Nature of vocabulary proficiency

A rich representation of a single word or a phrase (hereafter called an ‘item’ to emphasize that we are not only talking about single words, but also groups of words and phrases) includes, among others, strong and redundant connections between the item's orthographic, phonological, semantic, and syntactic properties; knowledge about its use in different contexts; its relationships to other words (Nagy & Scott Reference Nagy, Scott, Kamil, Mosenthal, Pearson and Barr2000), or what Perfetti (Reference Perfetti2007: 360) calls a ‘high quality lexical representation’. High quality representations contain rich interrelated information on the lexical items, and they are precise but flexible. For example, the word ‘quaint’ means ‘unusual’, but its precise use requires that it be utilized only if the unusual object also includes the dimension of being old-fashioned, and carries a positive connotation. ‘Quaint’ is also used flexibly to describe many different concepts (e.g., house, village, even a sense of humor). However, one's young Goth neighbor may be ‘unusual’ and ‘eccentric’, but probably not ‘quaint’.

In short, vocabulary knowledge is multi-dimensional, interrelated, and context dependent. This complexity has three important implications: (a) Vocabulary knowledge of an individual is not necessarily only reflected by the number of words that are known (breadth) but also by how rich and integrated the representations are for each item (depth); (b) High quality lexical representations develop incrementally through multiple exposures to the item in different contexts and uses; (c) Noticing the different contexts and uses of an item requires a rich conceptual understanding of the topic that forms the skeleton for that item. This rich knowledge base provides a scaffold for the learner to converge on a specific definition of an item or a nuanced understanding of the shades of meaning. For example, ‘arms’ means something different in a text about wars than in a text about body parts. Likewise ‘loan’ and ‘donate’ both imply a recipient getting something, but the nuance is the different expectations on the part of the recipient.

A substantial and growing body of work also points to the importance of academic language, and academic vocabulary in particular, for accessing the content of academic texts and talk; for learning to think and learn in subject areas; and for overall academic achievement (Nagy, Herman & Anderson Reference Nagy, Herman and Anderson1985; Scarcella Reference Scarcella2003; Baumann & Graves Reference Baumann and Graves2010; Snow Reference Snow2010; Nagy & Townsend Reference Nagy and Townsend2012). Academic items are even more challenging because they tend to be low in frequency, abstract, dense in meaning, and usually morphologically complex (Nagy & Townsend Reference Nagy and Townsend2012). In addition, different content areas have different types of specialized phrases that signal certain relationships in that content area (Schleppegrell Reference Schleppegrell2004; Zwiers Reference Zwiers2014). For example, in science and language arts texts, phrases that signal cause–effect relationships are salient (‘Consequently’; ‘As a result of’; ‘The character did that because. . .’) whereas in history texts, there are many phrases that signal chronological relationships (‘Following the establishment of’; ‘Prior to’).

Limited academic vocabulary has consistently been identified as an obstacle to student success (e.g., Snow & Kim Reference Snow, Kim, Wagner, Muse and Tannenbaum2007), restricting reading comprehension, and serving as a potential source of reading difficulty both for native English speakers as well as English Learners (ELs) (Biancarosa & Snow Reference Biancarosa and Snow2006). Reading comprehension is multi-faceted, requiring higher level processing (e.g., drawing on background knowledge); resolution of semantic and syntactic ambiguities; and the integration of many specific skills (word reading) with cultural and context knowledge. Each component of reading comprehension demands vocabulary knowledge, which is, in turn, multi-dimensional: it requires knowledge not only of a word's definition but also of its context-dependent connotations; its relationships to other words; and its morphological variations. Word knowledge is generally believed to develop over time, through multiple, contextualized encounters. This is particularly true of abstract, academic words.

Thus, vocabulary is both a key mechanism in and an important effect of the metacognitive process within the reading comprehension process. More specifically, students who know a great number of words have more abstract language at their disposal which they can use strategically while reading; in turn, students with a developed, complex understanding of language and strategies to manipulate language have the capacity to learn novel, challenging words more successfully (Sweet & Snow Reference Sweet and Snow2003). Furthermore, because less proficient readers tend to read less than their typically achieving peers, they encounter fewer numbers of words, and in particular, fewer low-frequency words, than do skilled readers (Stanovich Reference Stanovich1986). Struggling learners also tend to have less developed metacognitive strategies for word learning; for instance, they are poorly equipped to use surrounding words and grammatical clues to glean the meaning of unfamiliar words from the context, (e.g., Stoller & Grabe Reference Stoller, Grabe, Huckin, Haynes and Coady1993). Put together, this results in less or superficial content learning through academic texts, and, therefore, slower academic progress and overall lower levels of content-area knowledge (Nagy & Townsend Reference Nagy and Townsend2012). While these general mechanisms are at work in shaping the learning process for all students, ELs are particularly likely to have underdeveloped English language vocabularies (August et al. Reference August, Carlo, Dressler and Snow2005).

2.2 Vocabulary and comprehension interventions

There have been many discussions of vocabulary interventions (see McKeown et al. Reference McKeown, Beck, Omanson and Pople1985; Stahl Reference Stahl2003; Francis et al. Reference Francis, Rivera, Lesaux, Kieffer and Rivera2006; Graves Reference Graves2006; Marulis & Neuman Reference Marulis and Neuman2010; Pollard-Durodola et al. Reference Pollard-Durodola, Gonzalez, Simmons, Simmons and Nava-Walichowski2011; Neuman & Wright Reference Neuman and Wright2014; Silverman et al. Reference Silverman, Proctor, Harring, Doyle, Mitchell and Meyer2014) and although their targeted learners and contexts may differ, effective vocabulary and comprehension interventions tend to embody several characteristics, listed below, that enable their learners to develop rich, interrelated, precise, and flexible representations of items:

1. a. promoting a deep understanding of a relatively small number of critical items that are selected carefully, in contrast to the usual practice of facilitating a basic familiarity with a large number of words;

2. b. providing explicit instruction on the items, in addition to creating opportunities for incidental learning through exposure;

3. c. including reading, writing, listening, speaking, as well as multimedia in instruction;

4. d. discussing items in meaningful contexts that also provide a rich conceptual scaffold;

5. e. providing multiple exposures to the items in varied contexts;

6. f. acknowledging the specialized nature of academic language and its interrelatedness with content-area knowledge;

7. g. providing the learners with the analytic tools and strategies to understand the roots and different morphological forms (inflections, derivations) of words; and

8. h. developing a rich knowledge network that facilitates the discovery of an unfamiliar item's meaning and how it fits and enriches the content knowledge.

4.1 Replications across different learners

If the original program is so effective, it could also work for learners of different ages and proficiency levels who are learning academic content and English in different settings. It would be valuable for educators to know if this academic vocabulary learning program can be adapted and used across a range of educational contexts with similar outcomes.

Therefore, the first set of replications that we propose is to implement the program with individuals with increasing degrees of difference as compared to the original study population. The original study was conducted with middle schoolers, both native speakers and language minority students, using 4–6th grade reading materials. The closest replication would be to implement the intervention with high school ELs with emerging language needs. In the original study, the content was engaging (e.g., cyberbullying) and such content could be interesting for older readers as well. The material was selected to be at 4–6th grade reading level. In the first replication, the same materials could be used with high school students with reading levels around 6th grade. This will constitute a close replication, keeping the instructional strategies and content constant but with an older group. Other replications will need to keep the instructional approaches constant but include engaging texts with higher readability levels. Of course in these replications with different texts, another issue that awaits further study is how the specific target words and phrases can be selected with this content (Sagar, Fagan & Durgunoğlu Reference Sagar, Fagan and Durgunoğlu2014). We propose collaborating with educators and learners to identify topics which would be of interest to different populations, but also push their vocabulary skills toward more and more complex academic topics. Educators can also be instrumental in identifying the words that should be the focus of the intervention. Academic language corpora exist (e.g., the Academic Word List that was used in the original study (Coxhead Reference Coxhead2000)) that enable researchers and educators to select words systematically.

These studies could also be done with EFL learners in college. Although EFL students in universities may be more privileged in terms of economic/class background compared to the language minority students in the original article, it is worth exploring whether the same instructional approaches can work with different content. Furthermore, the original study design includes two key features which help to make the curriculum appropriate and relevant to the learners and the learning context: (1) engaging texts to use in the intervention can be selected in consultation with teachers, and tailored to students’ interests and needs, and (2) monthly meetings with teachers to be responsive to their implementation needs, which included troubleshooting difficult lessons.

As we move to learners of different ages and different educational settings, some of the instructional strategies may need to be modified. For example, in a replication with recent immigrants in adult ESL classrooms, the same instructional approach from the original study can be adopted, but given the learners’ relatively less familiarity with their new culture, a new part of the instruction has to be the laying of the groundwork for some cultural practices before starting vocabulary and content instruction. For example, before discussing cyberbullying (and how young people, especially girls, are silenced with this mechanism), some cultural foundations of gender roles may be covered.

Close replications can provide us with an indication of the boundary conditions for the applicability of the original intervention. Although there is a risk in implementing an intervention based on a certain population with a new group, the risk is mitigated in this particular case because the intervention strategies are based on a solid empirical and theoretical foundation. In addition, we are not arguing for reckless use of research designs, methods, and instruments from other studies to new populations, but through the collaboration with practitioners and careful ascertaining of whether underlying learning/teaching processes may be similar, it may be worth the effort to gain access to new settings and try out an intervention not originally intended for the learners.

4.2 Replications on conceptual knowledge

A second general focus for replication is the creating and activation of conceptual knowledge. Vocabulary items are meaningful within an overall conceptual framework; thus, how they are understood and interpreted depend on an understanding of the basic information surrounding them. To use the classic example, the object that comes to mind is different when the identical label ‘ball’ is encountered in a text describing a tennis match as compared to a text about a soccer match. The first context elicits the mental representation of a small, yellow and furry round object, whereas the second context might elicit the representation of a larger black and white round object. Likewise, the term ‘President’ has different meanings in different political systems. It can be a ceremonial post with a prime minister having more power (as in Turkey) or it can be a powerful position itself (as in the USA). Hence, the understanding of a single vocabulary item also requires some understanding of the context surrounding that item, or its conceptual scaffold. A second area proposed for replication is to explicitly examine the role of conceptual knowledge.

In the original study, the ‘engaging informational’ texts used in the intervention were selected from a magazine with the parameters that they would be of interest to an adolescent reader. Texts were on topics such as single-gender classrooms, high tech bullying, and TV viewing rates.

In classrooms, students are expected to understand academic texts and develop vocabulary knowledge about relatively unfamiliar (and because of unfamiliarity, sometimes perceived to be uninteresting) topics. Therefore, an important conceptual replication is to evaluate this intervention in unfamiliar and, consequently, (perceived to be) less engaging domains. These replications will add a needed dimension to the existing intervention structure, namely building a conceptual framework before the intervention. These can be hands-on activities in science classes (e.g., showing how a chemical worked and then introducing the vocabulary item ‘enzyme’, or providing visual representations of objects (e.g., detailed drawings of parts of a car engine before introducing the vocabulary item ‘axle’)).

Providing a conceptual framework before studying vocabulary items can be a useful strategy (Pollard-Durodola et al. Reference Pollard-Durodola, Gonzalez, Simmons, Simmons and Nava-Walichowski2011). In a recent pilot study, we have provided a conceptual framework before introducing history and civics vocabulary with adult ELs. Initial data indicate that situating the new vocabulary item within a conceptual scaffold improved its acquisition (Durgunoğlu et al. Reference Durgunoğlu, Sagar, Fagan and Brown2013).

Another factor that can be manipulated in developing this conceptual framework is L1. In college EFL settings and for certain adult education classes, the learners are likely to have acquired a strong educational foundation in their L1, becoming knowledgeable in certain content areas (e.g., history, geography, science). In contrast, the language minority students in the original study had no or limited instruction in their L1. In the replication studies with older learners, it may be possible to use their L1 content knowledge as a basis for building their English vocabulary, by situating the vocabulary items within their existing conceptual knowledge of topics. This can be accomplished by techniques such as activating the prior knowledge acquired in their L1 or enabling them to make cross-cultural comparisons (Durgunoğlu et al. Reference Durgunoğlu, Sagar, Fagan and Brown2013). It may also be possible to use the translations of complex concepts in the L1 of learners to provide a starting point. Of course, translations overlap to a larger extent in languages that share cognates (e.g., English and Spanish) or in fields like biology and medicine using slightly different versions of Latin- or Greek-based terminology (insulin in English, insulina in Spanish, ensülin in Turkish), but not necessarily for others. As we envision a conceptual replication of Lesaux et al., we would include more home language supports. These would include, for example, direct translations of items and activation of existing knowledge from L1 culture in order to establish the conceptual scaffolding for a complex topic. These supports would ideally undergo a piloting phase to ascertain their utility and then integrate accordingly.

In the original study with middle schoolers, the texts that were used were about social studies, more specifically, cultural studies. In Durgunoğlu et al. (Reference Durgunoğlu, Sagar, Fagan and Brown2013), the materials were about civics and history. Given the theoretical and practical grounding in existence, it can be expected that the approach in the original study can be used in other content areas, especially in fields such as biology or astronomy with their domain-specific words and phrases. Applying this approach to other content areas also awaits replication studies to assess if these instructional principles are generalizable to other fields. In these replications, the principles of instruction will remain constant, but the content area and the relevant vocabulary will be modified.