Model / text · All operations

Extract meaning from text

Sentiment, named entities, topics, language detection.

Status

In arcform

Not built yet

arcform does not do this yet. Its place on the roadmap

Shape of the result
one row out per row in, with columns added or changed
Level
needs an arcform operator

Variants

Extract fields from documents

Read invoice line items or key-value pairs out of scanned or structured documents.

Score or label each text

Add a sentiment score, language, class label or summary to each text value.

Other text and media analysis

Analyses of text or media that fit none of the other variants, such as acoustic features of audio.

What other tools call it

Meridian's classification; an independent blind rating agreed on 86.2% of 312 rows (exact class, version 2).

Alteryx Designer (7)
Apache Hop (1)
  • Detect languageread 2026-09-27

    Identify the natural language of a text field

KNIME Analytics Platform (2)
OpenRefine (1)
  • detectLanguage(s)read 2026-09-27

    Return the locale code of the language a string is written in

RapidMiner Studio (7)

Background

Information extraction (IE) is the task of automatically extracting structured information from unstructured and/or semi-structured machine-readable documents.[1] A broad goal of IE is to allow computation to be done on previously unstructured data.[1] Sentiment analysis, also known as opinion mining, is used to systematically identify, extract, quantify and study affective states and subjective information.[2]

When to use it

Sentiment analysis is widely applied to voice of the customer materials such as reviews and survey responses, to online and social media, and to healthcare materials.[2] The accuracy of a sentiment analysis system is, in principle, how well it agrees with human judgments.[2] Research has found that human raters typically agree only about 80% of the time when judging the sentiment of a text.[2] A computer system doing sentiment analysis will have trouble with negations, exaggerations, jokes or sarcasm, which are typically easy for a human reader to handle.[2] Read a sample of texts beside their scores before a sentiment column goes into a report, and keep the sample with the result. (Meridian's view)

Alteryx recommends not running its Text Pre-processing tool before its Sentiment Analysis tool, because pre-processing can remove features the sentiment tool relies on.[3] When Alteryx's Sentiment Analysis tool finds sentiment at sentence level, it uses punctuation to split the text into sentences, so the text must contain end punctuation.[3] Score sentiment on the text as it was written, before any cleaning step strips its punctuation or words. (Meridian's view)

Alteryx's Sentiment Analysis tool can only analyse data containing English text.[3] OpenRefine's detectLanguage function returns a string locale describing the language of a string, so "Hello, world!" gives "en".[4] Where a column mixes languages, detect the language of each value first and send each language to a model built for it. (Meridian's view)

The method

Information extraction typically involves processing human language texts by means of natural language processing (NLP).[1] Information extraction dates back to the late 1970s, in the early days of NLP.[1]

A basic task in sentiment analysis is classifying the polarity of a text at the document, sentence or feature/aspect level, as positive, negative or neutral.[2] Beyond polarity, sentiment classification can look at emotional states such as enjoyment, anger, disgust, sadness, fear and surprise.[2] Precursors to sentiment analysis include the General Inquirer, which provided hints toward quantifying patterns in text.[2]

RapidMiner's Text Classification operator applies a model trained to predict the most likely class of a text, such as whether its sentiment is positive or negative.[5]