Linguistic Data Analysis II

Session 4: Annotation Principles & Inter-Annotator Agreement

Day 2 · Annotation, Gold Standards & Metrics (2-1)

Masaki EGUCHI, Ph.D.

Tohoku University · Summer 2026

📋 Agenda

  1. Annotation — what it is, what it is used for, and which tasks this course targets
  2. The NLP evaluation workflow — reliability, validity, and the five steps you’ll run in S5–S6
  3. Evaluation metrics — P / R / F1, the confusion matrix, and Cohen’s κ
  4. Dataset for class tutorials — Arase et al. (2022), the example we work with from S5 on

🎯 Learning Objectives

By the end of this session, you will be able to:

  • Describe an annotation task as labels placed on a unit of analysis, and say why applied-linguistic findings depend on it.
  • Explain why this course targets sentence and text categorization, and what changes for span-level tasks.
  • Distinguish reliability from validity in annotation, and name what each one depends on.
  • Explain inter-annotator agreement: percent agreement vs. why Cohen’s κ corrects for chance — including quadratic weighted κ for ordered labels.
  • Read a confusion matrix and compute P / R / F1 from its four cells (TP · TN · FP · FN).

Annotation

What is annotation?

Annotation = adding interpretive labels to the available linguistic data.

  • POS — noun / verb / adjective…
  • Word sense — which meaning of bank?
  • Stance / engagement — is the writer hedging, endorsing?
  • Discourse moves — what is this sentence doing in the argument?
  • Error tags, …, CEFR level,

Annotation terminologies

  • Label:

    • The actual value (often category) we put as a result of the annotation
  • Unit of analysis:

    • The level/layer of phenomena that the specific annotation will be put on.
      • Morphology
      • Word
      • Multiword Units
      • Sentence
      • Paragraph …

Example with Part Of Speech tagging

POS tagging = labeling every token with its grammatical category (NOUN, VERB, ADJ…). One label per token — the simplest sequence-labelling task.

The_DET dogs_NOUN ran_VERB quickly_ADV ._PUNCT

Four of the 17 UPOS tags

Tag Category In the example
DET determiner The
NOUN noun dogs
VERB verb ran
ADV adverb quickly

Four out of 36 Penn tags set

Tag Category In the example
DT determiner The
NNS noun, plural dogs
VBD verb, past tense ran
RB adverb quickly

Even with POS, you have different choices.

  • The tag set is a design decision — the first one you make when you define an annotation task.

Syntactic Dependency

Dependency parsing = Identifying a binary syntactic relationships between a head and its dependency.

Dependency tree for “They buy and sell books.”

Annotation format

In NLP tasks, we often use CoNLL-U format.

ID   Form     Lemma   POS     TAG    MORPH                              HEAD DEP      
1    They     they    PRON    PRP    Case=Nom|Number=Plur               2    nsubj
2    buy      buy     VERB    VBP    Number=Plur|Person=3|Tense=Pres    0    root
3    and      and     CCONJ   CC     _                                  2    cc
4    sell     sell    VERB    VBP    Number=Plur|Person=3|Tense=Pres    2    conj
5    books    book    NOUN    NNS    Number=Plur                        4    obj
6    .        .       PUNCT   .      _                                  2    punct

Dependency tree for “They buy and sell books.”

Applications in L2 research

How do learner across proficiency level use collocations?

  • Adjective + Noun (JN)
  • Noun + Noun (NN)
  • Verb + Noun (VN)

Eguchi, M., & Kyle, K. (2023). L2 collocation profiles and their relationship with vocabulary proficiency: A learner corpus approach. Journal of Second Language Writing, 60, 100975. https://doi.org/10.1016/j.jslw.2023.100975

Granger, S., & Bestgen, Y. (2014). The use of collocations by intermediate vs. advanced non-native writers: A bigram-based study. International Review of Applied Linguistics in Language Teaching, 52(3). https://doi.org/10.1515/iral-2014-0011

Collocation extraction

Word Sense Disambiguation

Word-sense disambiguation = decide which meaning a word carries in context. Same form, different sense.

  • She sat on the bank of the river.riverbank
  • She deposited the cheque at the bank.financial institution

The surface form is identical — only context resolves the sense. Harder than POS: the label set is per word, not a fixed grammar.

Stance

Stance annotation = label how a writer positions themselves toward a proposition .

Unit of analysis is a span - textual segments with specified beginning and end.

Engagement Span Annotation (Eguchi & Kyle, 2023)

Discourse Moves

Move analysis = label what a stretch of text does rhetorically. Classic CARS model for research-article introductions (Swales):

Move Function
Move 1 Establishing a research territory
Move 2 Establishing a niche
Move 3 Presenting the present work

Kim & Lu (2024) had GPT annotate these moves — near-perfect when fine-tuned, though steps stayed hard. Unit: sentence/clause → one label.

Summary: NLP task by unit and output

Task Unit of analysis Label example Note
POS tagging Each token NOUN, VERB, ADJ Token-level sequence labelling — one label per token
Dependency parsing A pair of tokens nsubj, obj One relation per head–dependent pair
Stance annotation A stretch of text hedge, booster, ATTRIBUTE Span categorization — the span boundaries are part of the annotation
Rhetorical move analysis A sentence Background, Gap, Method Unit categorization — one label per unit
Sentence difficulty (CEFR) A sentence B2, C1, C2 Unit categorization — one label per unit
Register classification A whole text academic, news, fiction Unit categorization — one label per unit

The scope of the current course

We will focus mostly on sentence categorization and text categorization:

  • The evaluation code is easy to build.
  • the canonical {id, text, label} schema you met in S3 is sufficient.
data = {
        "id": 1,
        "text": "",
        "CoderA": "",
        "CoderB": "" 
        }

BUT you can apply the same workflow for different annotation tasks. Only the data and annotation gets complex.

Annotation is not the end-point, it is the beginning of the Applied work

In most of the Applied Linguistics work, performing annotation is one of the preliminary steps BUT NEVER a trivial one.

The subsequent analyses and conclusion depend on the annotation results.

Important

  • This is why we need a standardized workflow.

The NLP evaluation workflow

The NLP evaluation workflow we cover

Important

We evaluate the machine’s performance on a task, by comparing it against human-annotated answers.

  • We call these human-annotated dataset, gold-standard.
  • We want to consider discrepancies from human-annotated answer is error on the machine side.
  • How can we define the answer?
    • Reliability and Validity is core concern.

Reliability and Validity

What are reliability and validity?

Four targets showing dot patterns: a tight cluster away from the center (reliable, not valid); dots spread widely around the center (low reliability, low validity); dots scattered away from the center (not reliable, not valid); a tight cluster on the center (reliable and valid).

Reliability and Validity

  • Reliability:
    • How consistent the annotation results are (e.g., across human or AI coders).
    • How trustworthy your reported results are.
    • Depends on coder, scheme, type of data, familiarity, etc.
  • Validity:
    • How well the actual annotation captures what you are proposed to capture.
    • Depends on the quality of your coding scheme.

Proposed steps

Eguchi & Kyle (2024) lay out the annotation-and-evaluation workflow. We compress it into five steps, and you run steps ③–⑤ yourself in S5–S6.

Step What you do Original
Define the annotation task scope, unit of analysis, metrics
Operationalize into a scheme + guidelines Write/Adapt guideline / Pilot annotation
Build the gold standard Two (or more) blind coders, agreement, adjudication
Set the target = human agreement the ceiling for any model
Evaluate the LLM against gold P / R / F1, κ, confusion matrix

① Define the annotation task

  • Scope & purpose — What is the source text?
  • Design the taskinput → output over a unit of analysis of choice.
  • Reuse or draft — adopt an existing scheme / tag set if one fits; else draft from the literature.
  • Choose the metrics now (P / R / F1, κ) — so evaluation is planned, not retrofitted.
  • Sample data to represent the domain (proficiency, L1) and fix the unit.

② Operationalize into a scheme + guidelines

  • Turn the theoretical construct into descriptive rules.

Fuoli (2018) gives three principles:

  1. All choices accounted for.
  2. Guidelines tested & refined until reliable.
  3. Reliability always assessed — and reported.

If two trained coders can’t agree on it, a model can’t be trusted on it either.

An example of an annotation process

③ Build the gold standard

  1. Two coders annotate the same items blind.
  2. Measure inter-annotator agreement — percent + κ.
  3. Read the confusion matrix → refine the scheme, re-annotate.
  4. Adjudicate disagreements → a gold standard.

④ Measuring human agreement as a benchmark

  • Human inter-annotator agreement after modifying the scheme should be reported.

  • Human agreement lays a good benchmark.

⑤ Evaluate the LLM against gold

Finally, we will explore and evaluate LLM against gold-standard.

In classical machine-learning experiment, we split the entire dataset into three parts.

Split Roughly What it is for
Train 70% The model learns from these items.
Development (validation) 15% You compare settings here and pick the one to keep.
Test 15% Held back until the end. Score it oncePrecision · Recall · F1.

Using LLM, we might not need Train

Split Roughly What it is for
Development (validation) ??% You will change the prompt as many times as you want.
Test ??% Held back until the end. Score it oncePrecision · Recall · F1.

Proposed steps

Eguchi & Kyle (2024) lay out the annotation-and-evaluation workflow. We compress it into five steps, and you run steps ③–⑤ yourself in S5–S6.

Step What you do Original
Define the annotation task scope, unit of analysis, metrics
Operationalize into a scheme + guidelines Write/Adapt guideline / Pilot annotation
Build the gold standard Two (or more) blind coders, agreement, adjudication
Set the target = human agreement the ceiling for any model
Evaluate the LLM against gold P / R / F1, κ, confusion matrix

Evaluation metrics

Metrics

  • P / R / F1, and macro-F1 across classes.
  • Confusion matrix — which labels are confused with which.
  • Cohen’s κ — agreement corrected for chance.
  • Train / validation / test — the held-out logic (seed now; applied when we tune prompts in S7–S8).

The four outcomes: TP · TN · FP · FN

First pick one class as positive — say, “this sentence hedges.” Every prediction then belongs to one of four cells. Rows = gold (the truth), columns = the prediction:

Pred + Pred
Gold + TP FN
Gold FP TN
  • TP (true positive) — labelled hedging, and it was hedging. ✅
  • FP (false positive) — labelled hedging, but it was not.
  • FN (false negative) — labelled not hedging, but it was hedging.
  • TN (true negative) — labelled not hedging, and it was not. ✅

Precision & Recall

Two questions about the positive class, from the same four cells. Say our detector scored the following on a batch of sentences:

Pred + Pred
Gold + TP = 8 FN = 4
Gold FP = 2 TN = —

Precisionof everything it labelled positive, how much was correct?

Recallof everything that was actually positive, how much did it identify?

Precision & Recall

Precisionof everything it labelled positive, how much was correct?

\[\text{Precision} = \frac{TP}{TP + FP} = \frac{8}{8 + 2} = 0.80\]

Recallof everything that was actually positive, how much did it identify?

\[\text{Recall} = \frac{TP}{TP + FN} = \frac{8}{8 + 4} = 0.67\]

F1 — the harmonic mean, so a high value on one side cannot compensate for a low value on the other:

\[F_1 = 2 \cdot \frac{P \cdot R}{P + R} = 2 \cdot \frac{0.80 \cdot 0.67}{0.80 + 0.67} \approx 0.73\]

Two coders, same sentences — Accuracy

Not let’s say two annotators label the same 50 sentences (+/−):

Coder B Total
+
Coder A + 10 5 15 (30%)
5 30 35 (70%)
Total 15
(30%)
35
(70%)
50

Observed agreement = the diagonal ÷ total:

\[p_o = \frac{10 + 30}{50} = 0.80\]

Cohen’s κ — agreement beyond chance

Cohen’s κ (the two-rater, nominal case) subtracts the agreement you’d expect by chance:

\[\kappa = \frac{p_o - p_e}{1 - p_e}\] \(p_e\) = the agreement they would reach by chance, using each coder’s own marginal rate (row/column totals ÷ 50).

Cohen’s κ — agreement beyond chance

For each label, multiply the two coders’ rates:

\[p_e = \underbrace{P(A{+})\cdot P(B{+})}_{\text{both say }+} \;+\; \underbrace{P(A{-})\cdot P(B{-})}_{\text{both say }-}\]

Here both coders marked “+” 15/50 = 0.30 and “−” 35/50 = 0.70:

\[p_e = (0.30)(0.30) + (0.70)(0.70) = 0.58 \qquad \Rightarrow \qquad \kappa = \frac{0.80 - 0.58}{1 - 0.58} \approx 0.52\]

How much κ is enough?

There’s no single cut-off — you read κ against a benchmark.

Cohen’s κ Landis & Koch (1977) McHugh (2012)
< 0.00 Poor
0.00–0.20 Slight None
0.21–0.40 Fair Minimal
0.41–0.60 Moderate Weak
0.61–0.80 Substantial Moderate
0.81–1.00 Almost perfect Strong

Tip

Our two coders’ raw 80 % agreement is only κ ≈ 0.52 once chance is removed — inadequate on that rule. This difference is why κ is reported instead of raw agreement.

Dataset for class tutorials — Arase et al. (2022)

Arase, Uchida & Kajiwara (2022)

“CEFR-Based Sentence Difficulty Annotation and Assessment” (EMNLP 2022).

  • The problem. Simplifying text for learners requires knowing how hard a sentence is.

  • Goal: Creating a corpus that is annotated for sentence difficulties according to CEFR levels.

  • How did they operationalize CEFR levels?

Methodology

  • They used CEFR “can-do” statements to infer the level of the passage.
Level Overall reading comprehension descriptor
C2 Can understand virtually all types of texts including abstract, structurally complex, or highly colloquial literary and non-literary writings.
C1 Can understand in detail lengthy, complex texts, whether or not these relate to their own area of speciality, provided they can reread difficult sections.
B2 Can read with a large degree of independence, adapting style and speed of reading to different texts and purposes. Has a broad active reading vocabulary, but may experience some difficulty with low-frequency idioms.
B1 Can read straightforward factual texts on subjects related to their field of interest with a satisfactory level of comprehension.
A2 Can understand short, simple texts on familiar matters of a concrete type which consist of high frequency everyday or job-related language.
A1 Can understand very short, simple texts a single phrase at a time, picking up familiar names, words and basic phrases and rereading as required.

Council of Europe (2020). Common European Framework of Reference for Languages: Learning, teaching, assessment — Companion volume.

A problem with the approach

The descriptors describe what a learner can do — not what a sentence is.

  • They talk about text types (“literary writings”, “factual texts”) and reading conditions (“provided they can reread”).
  • None of that applies to a single, context-free sentence.

Making the scale apply to one sentence is the design problem

What the labels look like

One example sentence per level, from the corpus (Arase et al., 2022, Table 1):

Input — one sentence Output — one level
She had a beautiful necklace around her neck. A1
Some experts say the classes should be changed. A2
Historically there have also been negative consequences. B1
Alligators are generally timid towards humans and tend to walk or swim away if one approaches. B2
The metal-carbon bond in organometallic compounds is generally highly covalent. C1
In the past, non-photosynthetic plants were mistakenly thought to get food by breaking down organic matter in a manner similar to saprotrophic fungi. C2

Why do we use CEFR-SP project?

  • The task is familiar. Simplification — and judging what level a sentence is pitched at — is something language teachers and applied linguists are interested in.
  • The task is simple enough. One sentence, one label. Simple enough for the tutorial example.

A good tutorial project. Interesting enough to be worth doing, small enough to actually finish in five days.

Note

Skim §3.1 and §3.2 — about a page and a half. That’s where we start the afternoon session.

In the afternoon

  • S5 — Gold-Standard Annotation & Agreement (hands-on): extract Arase’s two design decisions, then build a gold standard and measure agreement — executes Phases ①–③.

  • S6 — Gold Standards & Evaluation Metrics (hands-on): score an LLM against that gold — executes Phases ④–⑤.

Any questions?