Collect and clean text
Gather representative documents and apply tokenisation, stopword removal and lemmatisation; preserve examples of noisy, short and multilingual inputs.
Discover latent topics with LDA. Judge topic coherence.
Latent Dirichlet Allocation (LDA) is an unsupervised method that represents documents as mixtures of topics and topics as distributions over words. Typical concerns include choosing the topic count, preprocessing (stopwords, lemmatisation), and evaluating coherence and human interpretability. Common failure cases are short documents, heavy noise, and topics that split or merge semantically.
Learning concept · Not a validated service
Latent Dirichlet Allocation (LDA) is an unsupervised method that represents documents as mixtures of topics and topics as distributions over words. Typical concerns include choosing the topic count, preprocessing (stopwords, lemmatisation), and evaluating coherence and human interpretability. Common failure cases are short documents, heavy noise, and topics that split or merge semantically.
A proposed application: organise a large collection of support tickets or news articles into discoverable topics so analysts can triage issues faster. Human reviewers should validate topic labels before any automated routing.
Gather representative documents and apply tokenisation, stopword removal and lemmatisation; preserve examples of noisy, short and multilingual inputs.
Train an LDA implementation (e.g. gensim or scikit-learn) over an appropriate bag-of-words matrix and tune the number of topics by coherence metrics.
Compute topic-word lists and topic distributions per document and ask subject-matter experts to label and validate coherence.
Report topic coherence and stability across runs, monitor drift in topic distributions, and expose human-review tools before automation.
The supplied starter splits six hand-written sentences with binary labels, fits a TF-IDF unigram+bigram vectoriser and a LogisticRegression classifier in a scikit-learn Pipeline, then prints a classification report and a single sample prediction. It implements supervised text classification rather than any LDA topic modelling.
model = Pipeline(
steps=[
("tfidf", TfidfVectorizer(ngram_range=(1, 2), min_df=1)),
("classifier", LogisticRegression(max_iter=1000)),
]
)
model.fit(X_train, y_train)
predictions = model.predict(X_test)The code contains no LDA model or topic-distribution outputs: it is a supervised TF-IDF + LogisticRegression classifier on six labelled sentences and does not perform unsupervised topic extraction.
Proposed extension: replace the starter pipeline with a bag-of-words or count matrix, train an LDA model (gensim or scikit-learn), and build a reviewer UI that shows topic-word lists and representative documents for labelling.
This is a potential application pathway, not a delivered product. The supplied starter does not implement this service or validate it with real users.
Networkers Home runs this topic inside its AI Engineer Course, with placement support and hands-on labs.