TED Talks have a lot of education potential for student beyond the interesting content that can be gained from listening to them. The engaging presentation style can help students pick up effective presentation techniques. They offer students extensive or narrow listening practice to informal, formal, and academic (or academic-like) speaking; pronunciation practice (especially through the TED Corpus); reading practice via their transcripts, and can also be a source of vocabulary learning. In order to gain as much benefit as possible from TED Talks, it is important to know how difficult they are in terms of vocabulary, which level of students TED Talks are appropriate for, and how to support these students’ comprehension of TED Talks. Nurmukhamedov (2017) looked at the lexical coverage of TED Talks in order to understand how much vocabulary a person needs to know to understand these presentations, and whether the disciplinary topic changes that number.
Lexical Coverage and Previous Studies
Lexical coverage can be defined as the percentage of words in a text readers know. Most research has shown that readers need to know 95% for good understanding, and 98% for adequate comprehension. That is, with 95% coverage, 1 word out of 20 will be unknown; for 98%, 1 word out of 50 will be unknown. This is true for reading as well as listening.
Past analyses of TED Talks have shown that learners need be familiar with the 2,000 and 3,000 level word families (2,000 and 3,000 most frequent words) to reach 91% and 93% coverage (Wang, 2012). Another study showed that 95% coverage meant familiarity with 4,000 word families while 98% coverage meant 9,000 word families (Coxhead and Wall, 2012).
Present Study and Findings
The present study partially replicates Coxhead and Wall by increasing the number of TED Talks study, as well as shifting the lexical focus. The current study investigates 400 TED Talks (about 1,000,000 words) in 4 disciplines (business, global issues, science, technology – 100 videos each), focuses solely on word families, and also accounts for proper nouns and rare marginal words, which have been indicated as a potential problem for listening comprehension.
The study found that students must be familiar with 4,000 word families, proper nouns, and marginal words to reach 95% coverage. They must be familiar with 8,000 words families for 98% coverage. Being familiar with only the 1,000 most frequent words will allow learners to reach only 85% coverage (3 words unknown for every 20 words). This pattern holds true for the disciplines of business, global issues, and technology. However, a learner would need 10,000 word families to reach 98% coverage for science.
Interestingly, although a comparison of TED and academic language was not a focus of the research, they did find that 3.79 to 3.90% of the AWL is covered in TED Talks whereas it is about 4.41% in academic spoken English (spoken English has far less coverage than written English).
Implications
To get beyond a very basic gist of TED Talks, and to not lose patience while listening, students should be at a higher-intermediate and above level (though there was no indication of what this may be in terms of CEFR or another scale). In terms of instruction and material design, vocabulary should be considered when utilizing TED Talks.
- The Vocabulary Size Test (VST) can be used to indicate students’ lexical readiness. This is a freely available test what lexical bands students know. According to the author, “following TED Talks might get harder if learners are not aware of vocabulary beyond 2,000–3,000 word families” (p. 781). The test can also help indicate which vocabulary bands need the most attention.
- Identify and pre-teach topic related vocabulary.
- Consider narrow listening (listening to TED Talks on the same topic) to reinforce these topic-specific words.
- Identify and pre-teach proper nouns that could be a source of confusion.
- Studies that changed proper nouns (e.g. names) to more common or culturally appropriate ones showed that being familiar with proper nouns aided comprehension (Erten & Razi, 2009; Kobeleva, 2012)
Takeaway
TED Talks offer a powerful language learning tool and have a number of benefits. There are many ways to use TED Talks for intensive and extensive language learning, but, as this study indicates, having a large vocabulary is essential if learners are going to get any use out of these talks. I would recommend using short excerpts and scaffolding instruction to learn important vocabulary (and pronunciation) before moving on to other listening- and meaning-based activities. For a number of ideas on how to use TED Talks, you can check out my post Getting in Bed with TED.
References
Coxhead, A., & Walls, R. (2012). TED Talks, vocabulary, and listening for EAP. TESOL ANZ Journal, 20, 55–65.
Erten, I., & Razi, S. (2009). The effects of cultural familiarity on reading comprehension. Reading in a Foreign Language, 21, 60–77.
Kobeleva, P. (2012). Second language listening and unfamiliar proper names: Comprehension barrier? RELC Journal, 43, 83–98.
https://doi.org/10.1177/0033688212440637.
Nurmukhamedov, U. (2017). Lexical coverage of TED Talks: Implications for vocabulary instruction. TESOL Journal, 8(4), 768-790.
Wang, Y. (2012). An exploration of vocabulary knowledge in English short talks: A corpus driven approach. International Journal of English Linguistics, 2, 33–43. https://doi.org/10.5539/ijel.v2n4p33.
