Is there a way to review (NER) examples with the highest loss?

Hi, I am training a NER model, and even though I try to be accurate, there may well be cases in which I make mistakes (typically, I swap a label with another).

Is there a way to leverage a trained model to review first in prodigy training examples that come with the highest (training) loss, so to review/correct them? I could review each example manually, but that'd be time consuming.

This is inspired by and somewhat similar to Review examples where the model fails to predict correctly, but my goal is correcting annotation mistakes in the training set.


I guess this question is similar to this thread? Can active learning help reduce annotation inconsistencies? - #2 by SofieVL

Basically what you could do is train a model on the whole dataset or part of it, make predictions, and compare those to the original annotations you created. Where the two diverge, something may be going on.

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Thanks @SofieVL ! As for the comparsion, I will need to compare spans and compute some sort of similarity between the spans of predictions and annotations, is that correct? Would be cool to use directly the model loss though :wink:

Hi, not quite what you're looking for with evaluating based on loss directly but we're thinking about including this recipe in Prodigy at some point in the future. Specifically for reviewing NER data, this recipe sorts by the F1 Score calculated per example in the provided evaluation set. It then uses the new Overlapping Spans UI to show the difference between annotated entities and predicted entities. Let us know if you find it useful!

If you specifically want to sort by loss, have a look at the spaCy NER model implentation. It's definitely doable and feel free to respond to this thread if you get it figured out.

CLI Usage

For understanding what your model learned, run this on your evaluation set:

prodigy ner.review_hardest my_dataset ./trained_spacy_ner_model /path/to/evaluation_set.jsonl -F path/to/this/

For potentially identifying inconsistencies/errors in training data, you can run this on your training set:

prodigy ner.review_hardest my_dataset ./trained_spacy_ner_model /path/to/training_set.jsonl -F path/to/this/

Recipe Definition

from typing import List, Optional, Union, Iterable
import murmurhash
import spacy
from spacy.language import Language
from import Example
from spacy.tokens.doc import Doc, SetEntsDefault
from spacy.util import get_words_and_spaces
import copy

from prodigy.components.db import connect
from prodigy.components.preprocess import split_sentences, add_tokens, make_raw_doc
from prodigy.components.loaders import get_stream
from prodigy.core import recipe
from prodigy.util import set_hashes, log, split_string, get_labels, copy_nlp
from prodigy.util import INPUT_HASH_ATTR, TASK_HASH_ATTR, msg
from prodigy.types import TaskType, StreamType, RecipeSettingsType

    # fmt: off
    dataset=("Dataset to save annotations to", "positional", None, str),
    spacy_model=("Loadable spaCy model for tokenization or blank:lang (e.g. blank:en)", "positional", None, str),
    source=("Data to annotate (file path or '-' to read from standard input)", "positional", None, str),
    loader=("Loader (guessed from file extension if not set)", "option", "lo", str),
    label=("Comma-separated label(s) to annotate or text file with one label per line", "option", "l", get_labels),
    exclude=("Comma-separated list of dataset IDs whose annotations to exclude", "option", "e", split_string),
    score_key=("Score to use in sorting examples", "option", "sk", str),
    # fmt: on
def review_hardest(
    dataset: str,
    spacy_model: str,
    source: Union[str, Iterable[dict]],
    loader: Optional[str] = None,
    label: Optional[List[str]] = None,
    exclude: Optional[List[str]] = None,
    score_key: str = "ents_f",
) -> RecipeSettingsType:

    log("RECIPE: Starting recipe ner.review_hardest", locals())
    nlp = spacy.load(spacy_model)
    labels = label  # comma-separated list or path to text file
    if not labels:
        labels = nlp.pipe_labels.get("ner", [])
        if not labels:
  "No --label argument set and no labels found in model", exits=1)
        msg.text(f"Using {len(labels)} labels from model: {', '.join(labels)}")
    log(f"RECIPE: Annotating with {len(labels)} labels", labels)
    stream = get_stream(source, loader=loader, rehash=True, input_key="text")
    # Add "tokens" key to the tasks, either with words or characters

    def get_tasks(
        nlp: Language, stream: StreamType
    ) -> StreamType:
        tuples = ((eg["text"], eg) for eg in stream)
        scored_tasks = []

        for pred, eg in nlp.pipe(tuples, as_tuples=True):
            combined = copy.deepcopy(eg)
            spans = eg.get("spans", [])

            if "tokens" in eg:
                tokens = [token["text"] for token in eg["tokens"]]
                words, spaces = get_words_and_spaces(tokens, eg["text"])
                reference = Doc(nlp.vocab, words=words, spaces=spaces)
                reference = nlp.make_doc(eg["text"])

            ents = [reference.char_span(s["start"], s["end"], label=s["label"]) for s in spans]
            reference.ents = ents

            for ent in pred.ents:
                label = ent.label_
                if not labels or label in labels:
                    start = ent.start_char
                    end = ent.end_char
                        "start": start,
                        "end": end,
                        "label": f"{label}:PREDICTED"

            combined["spans"] = sorted(spans, key = lambda s: s["start"])

            if len(combined["spans"]) >= 0:
                example_scores = nlp.get_pipe("ner").score([Example(pred, reference)])
                score = example_scores[score_key]
                if score is not None:
                    scored_tasks.append((score, combined))

        sorted_tasks = sorted(scored_tasks, key=lambda x: x[0])
        for score, task in sorted_tasks:
            if "meta" not in task:
                task["meta"] = {}
            task["meta"][score_key] = round(score, 3)
            yield task

    stream = get_tasks(nlp, stream)
    stream = add_tokens(nlp, stream)

    def before_db(answers):
        for eg in answers:
            filtered_spans = [span for span in eg.get("spans", []) if not span["label"].endswith(":PREDICTED")]
            eg["spans"] = filtered_spans
        return answers

    return {
        "view_id": "spans_manual",
        "dataset": dataset,
        "stream": stream,
        "exclude": exclude,
        "before_db": before_db,
        "config": {
            "lang": nlp.lang,
            "labels": labels,
            "exclude_by": "input",
            "auto_count_stream": True,
            "overlapping_spans": True,

@kab this definitely goes in the right direction, thanks!

Only thing that is not clear to me is how I can amend the original dataset when I see the model pointing out nonsensical labels in the original set.

In the recipe, I can review annotations that are "unexpected" by the model, and save them in a new dataset. How to integrate the corrected/reviewed spans with the rest of the original dataset (i.e. examples that are not surprising for the model, which I don't have time to review)?

This recipe uses a before_db callback to strip out the annotations that have ":PREDICTED" from the spans. This way if you just hit accept, the saved example would be the same as the original. If you want to change one of these annotations, you can use the standard manual NER labeling interactions to adjust/add/remove spans. Any changes you make are saved to the dataset you provided the recipe (e.g. my_ner_corrections).

All examples in a saved dataset will have a "_task_hash" and an "_input_hash". So you could take the _input_hash of each example in the my_ner_corrections dataset create a set of those hashes and compare each example in your original dataset (e.g. my_ner_data) to the input hashes of the corrections and filter the overlaps. This way all the data you didn't review stays the same and you replace the incorrect annotations with your new corrections.

So something like:

prodigy db-out my_ner_data ./my_ner_data.jsonl # Dataset with original annotations
prodigy db-out my_ner_corrections ./my_ner_corrections.jsonl # Dataset with corrections from this recipe

Then load these files in Python with srsly

import srsly
from prodigy.util import INPUT_HASH_ATTR # If you have duplicated inputs you want to keep use TASK_HASH_ATTR

merged_data = []
original = srsly.read_jsonl("./my_ner_data.jsonl")
corrections = list(srsly.read_jsonl("./my_ner_corrections .jsonl"))
correction_hashes = set([eg[INPUT_HASH_ATTR] for eg in corrections])

for eg in original:
    if eg[INPUT_HASH_ATTR] not in correction_hashes:
merged_data += corrections
srsly.write_jsonl("./merged_data.jsonl", merged_data)
1 Like

Hi Kabir, that recipe is very useful! Thanks for posting it. It gave me insight into where my model is going wrong and also let me correct some annotations. Earlier you mentioned that it you're considering to include it in a future version of Prodigy and that sounds like a great idea.