NLP Learning Notes / NLP001

NLP: from language to research applications

Natural language processing (NLP) uses computational methods to work with human language. Systems use explicit rules or learn patterns from data to analyze, extract, predict, and generate information. Large language models are one family of technologies within this field. [1]

  • section
  • key term
  • reading note
ELLE · READING COMPANION

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A few foundations, with Elle

Open a term when you need it, then try one quick question.

NLP

Computational methods for analysing and generating human language.

Context

The surrounding words and situation help determine what an expression means.

Summarization

Condensing a longer text while retaining its important information.

Can the same sentence mean different things in different contexts?

The big picture

NLP study diagram covering language features, models, common tasks, speech analysis, and interview applications ⤢ Enlarge

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Information in language

PerspectiveWhat to look forExample
Word structure and meaningHow words are formed and what they meanhappy → unhappy; “satisfied” versus “not satisfied”
Sentence structure and meaningRoles, evaluation targets, and contrasts“The explanation was clear, but the wait was too long” evaluates two things differently
Context and intentReferences across sentences and the purpose of an utterance“These instructions are confusing” may be a request for clarification

These perspectives help explain language; they are not mandatory sequential stages in every model. [1][2]

Conceptual illustration of morphology, syntax, semantics, and pragmatics
InfographicConceptual illustration of morphology, syntax, semantics, and pragmaticsClick to open full size

A conceptual illustration, not a fixed architecture inside a model. NLU and NLG need not follow strictly inverse pipelines, and context matters across perspectives.

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Speech analysis: how something is said

CueWhat it captures
LoudnessHow loud or soft the voice is, and how it changes
Speaking rateHow quickly or slowly someone speaks
DeliveryIntonation, stress, pauses, and related patterns

Listen: same words, two patients

“I am okay with this treatment.”

Patient Asounds sure

About 1.6 s · one smooth phrase, no pauses

Patient Bsounds unsure

About 3.2 s · slower, with two pauses of about 0.4 s

Transcribed, both recordings read exactly the same. Their loudness is almost identical; the difference lies mainly in speaking rate and pauses, which are the cues a transcript drops. Voice analysis can flag moments like this for a second listen. It offers a cue, not a diagnosis.

The clips are synthesized voices made for this note's companion video, not recordings of real patients. Durations and pauses were measured from the audio.

Interpret acoustic and prosodic cues alongside the words and the situation. A plain transcript usually does not preserve all of them; analysis needs audio or the relevant acoustic features. Speech and text analysis can be combined, but measuring vocal features is different from interpreting linguistic content. [3]

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Common tasks

TaskThe question it addresses
Sentiment analysisWhat is being evaluated positively, negatively, or in mixed terms?
Emotion cue recognitionWhat feelings are expressed or implied? A cue is not a clinical diagnosis
Information extractionWhich themes, entities, or events should become fields or labels linked to the source?
SummarizationWhat are the main points of an interview, meeting, or body of material? Preserve important contrasts and uncertainty
Translation and question answeringHow can information be expressed in another language, or used to answer a question?

Summarization concerns the key content, while speech analysis examines vocal cues. A workflow can use both.

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My perspective & use case

My starting point

Language itself makes NLP more approachable. Connecting words, sentences, and context to specific tasks helps me understand the broader framework.

My research direction

I have worked with interviews by manually marking passages and extracting keywords. I want to explore NLP-assisted organization and summaries of participants' main points.

  1. Research question
  2. Information needed
  3. Fields or labels
  4. Source check

Usefulness depends on omissions, label quality, and time saved after corrections.

Exploring next

How text becomes model input

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References

  1. Jurafsky & Martin, Speech and Language Processing ↗
  2. Words and Tokens ↗
  3. audEERING, prosody and speech features ↗

Further reading

Tang et al. (2023), evaluating medical evidence summarization ↗

Its findings concern particular models and a specific task; they do not validate an interview-analysis workflow.

原图 / Original ↗