The Research Behind TroveReader

TroveReader is not just an app, it's a tool built around decades of research in Second Language Acquisition (SLA) to help you make progress towards your language learning goals.

Our core philosophy is that sustained exposure to meaningful, comprehensible language, often described as comprehensible input, is a powerful foundation for language learning.

But we don't think learners should simply consume language and hope that everything sticks. Research suggests that vocabulary learning from context is a gradual process. Attention, repeated encounters, deliberate study, and retrieval can all provide additional opportunities for learning.

TroveReader is designed around that balance: read what interests you, notice the language that matters, keep it in context, and encounter it again.

Below is a curated, non-exhaustive selection of research that has informed our approach.

Stephen D. Krashen

Krashen is one of the most influential figures in the development of input-oriented approaches to SLA. His work placed comprehensible input and meaningful communication at the center of a theory of language acquisition and has had a major influence on approaches to extensive reading and language learning through meaningful exposure.

• Krashen, S. D. (1982).
  Principles and Practice in Second Language Acquisition.Pergamon Press.

  This foundational work lays out Krashen's five hypotheses of second language acquisition, including the Input Hypothesis and the distinction between conscious learning and subconscious acquisition.

• Krashen, S. D. (2004).
  The Power of Reading: Insights from the Research.Heinemann.

  A collection of research and arguments concerning free voluntary reading and its relationship to literacy and language development.

How this informs TroveReader: We want language learners to spend substantial time understanding language that is meaningful to them, rather than turning every encounter into an exercise.

Marlise Horst

Horst's research provides important evidence that vocabulary can be acquired incidentally through reading in a second language. It also illustrates an important limitation: encountering a word does not mean that a learner will immediately or completely learn it.

• Horst, M., Cobb, T., & Meara, P. (1998).
  Beyond A Clockwork Orange: Acquiring Second Language Vocabulary Through Reading.Reading in a Foreign Language, 11(2), 207–223.

  Tracking learners reading for pleasure, this study demonstrated that incidental vocabulary acquisition through reading is possible. It also highlighted the gradual nature of vocabulary learning and the importance of repeated encounters with words.

How this informs TroveReader: Reading remains the main activity. When a useful word or phrase catches your attention, TroveReader lets you save it together with the sentence in which you encountered it, keeping the vocabulary connected to meaningful context.

I. S. P. (Paul) Nation

Nation is one of the leading researchers in second language vocabulary acquisition. His work emphasizes that knowing a word is multidimensional: vocabulary knowledge involves far more than simply knowing a translation.

• Nation, I. S. P. (2001).
  Learning Vocabulary in Another Language.Cambridge University Press.

  A major research-based treatment of vocabulary acquisition, covering learning from context, deliberate vocabulary study, word knowledge, frequency, and the conditions that support vocabulary development.

• Nation, I. S. P., & Waring, R. (2019).
  Teaching Extensive Reading in Another Language.Routledge.

  A practical, research-informed treatment of extensive reading and how large amounts of meaningful reading can be incorporated into language learning.

How this informs TroveReader: A saved word is not just a translation. Learners can write their own notes, get explanations from our integrated AI, retain the original sentence and add additional contexts you see it in, all to build a rich record of how the language is actually used.

Jan Hulstijn

Hulstijn's work helped clarify the relationship between incidental and intentional vocabulary learning. His work highlights the importance of both the depth and quality of processing that takes place when learners encounter and interact with new language.

• Hulstijn, J. H. (2001).
  Intentional and Incidental Second Language Vocabulary Learning: A Reappraisal of Elaboration, Rehearsal and Automaticity.In P. Robinson (Ed.), Cognition and Second Language Instruction. Cambridge University Press.

  This chapter examines how intentional and incidental vocabulary learning interact, and how elaboration, rehearsal, and automaticity contribute to vocabulary development.

How this informs TroveReader: We don't ask learners to study every word they encounter. Instead, the learner decides which words deserve additional attention. A useful encounter can remain incidental; a word that matters can become something the learner deliberately processes and revisits.

Rob Waring & Misako Takaki

Waring and Takaki's experimental work illustrates one of the most important realities of incidental vocabulary learning: words can be learned from reading, but a single reading experience does not guarantee durable learning.

• Waring, R., & Takaki, M. (2003).
  At What Rate Do Learners Learn and Retain New Vocabulary from Reading a Graded Reader?Reading in a Foreign Language, 15(2), 130–163.

  Studying Japanese learners reading a graded reader, the researchers found that vocabulary could be learned incidentally, but that most of the words tested were not learned. More frequent words were more likely to be learned and retained.

How this informs TroveReader: Meaningful exposure is the beginning, not necessarily the end, of vocabulary learning. This is why TroveReader provides opportunities to save vocabulary, review it, export it, and notice words again when they reappear in later reading. It's also why we have a library of graded readers, news feeds and podcasts, plus the ability for you to import your own texts, allowing endless sources of reading material.

Zhouhan Jin & Stuart Webb

Recent research by Jin and Webb is particularly relevant to TroveReader's note-taking and vocabulary features. Their work examines what happens when learners take notes while processing language input.

• Jin, Z., & Webb, S. (2025).
  How Do Different Forms of Note-Taking Affect Second Language Vocabulary Learning?Language Learning, 75(4), 1185–1221.

  This study showed that note-taking produced vocabulary gains on a meaning-recall measure. It also found that writing unfamiliar target words in notes was associated with vocabulary learning.

• Jin, Z., & Webb, S. (2025).
  To What Extent Does Reviewing Notes Affect L2 Vocabulary Learning?Applied Linguistics, 47(2), 216–236.

  A follow-up study examined the role of reviewing notes after learning. The findings provide further evidence that note-taking and subsequent review can play complementary roles in vocabulary learning, although their effects vary according to the type of learning and assessment involved.

How this informs TroveReader: We don't want saving a word to break the flow. When a word or phrase catches your attention, you can quickly save it, add the definition or your own notes, and keep the original context alongside it. This turns an encounter with a new word or phrase into an opportunity for more deliberate practice, now or later.

Zoltán Dörnyei

Dörnyei is one of the most influential researchers on motivation and individual differences in second language learning. His work emphasizes the importance of motivation, learner characteristics, and the relationship between learners and their learning environments.

• Dörnyei, Z. (2005).
  The Psychology of the Language Learner: Individual Differences in Second Language Acquisition.Lawrence Erlbaum Associates.

  A major account of individual differences in language learning, including motivation, personality, learning strategies, and self-regulation.

How this informs TroveReader: Learners are more likely to sustain a reading habit when they have something they genuinely want to read. TroveReader therefore lets learners bring their own interests into language learning rather than limiting them to a fixed collection of lessons.

Beniko Mason

Mason's work has contributed to research and practice around extensive reading and listening, particularly approaches that emphasize large amounts of comprehensible and engaging language input.

• Mason, B. (2017).
  JALT2016 Plenary: In-session reading and its effect on the motivation of university students in Japan.

  This presentation reports research into in-session reading and its relationship with motivation and language development, contributing to the broader literature on extensive reading and comprehensible input.

How this informs TroveReader: We want reading to be something language learners can find enjoyable and sustain. The ability to bring your own content into TroveReader is intended to make meaningful and engaging reading easier to start and easier to continue.

What we know and what we don't

The field of SLA is vast and continually evolving. There is no single technique that has been shown to do all of the work of language acquisition, and no single study has established how every individual learns a language.

What the research does support is a more nuanced picture. Meaningful reading and listening can provide substantial opportunities for language exposure and vocabulary development. But learning is a gradual process.

This is why TroveReader is designed around both exposure and active engagement. Reading provides the input. Noticing draws attention to language. Saving a word and explaining it in your own terms provides an opportunity for more deliberate processing. Preserving the original context keeps the language connected to meaningful use. Reviewing and encountering the word again provide further opportunities for retrieval and learning.

We don't claim that every one of these steps is necessary every time, or that TroveReader can replace all other forms of language learning. Instead, we built a tool around a simple idea: make it easier to spend time reading and listening to interesting material in the language you're learning, and make the moments when you want to pay closer attention easy to act on.