Practical overview
When it fits
Use it when generated outputs can be paired row by row with reference examples and you want automated metric reports through a CLI or Python workflow.
Who it is for
- Researchers evaluating natural-language-generation experiments
- Developers comparing machine-translation or dialogue-generation outputs with reference text
Documented uses
- Calculate automated metric scores for a corpus of generated sentences.
- Compare an individual generated sentence with one or more reference strings through the Python API.
- Reuse loaded models for repeated evaluations in a script.
Requirements & limits
- Reference and hypothesis rows must correspond to the same examples.
- Setup requires Java 1.8 or higher and downloads data such as models and embeddings.
- The metric set includes BLEU, METEOR, ROUGE, CIDEr, SPICE, SkipThought cosine similarity, Embedding Average cosine similarity, Vector Extrema cosine similarity and Greedy Matching.
Check current requirements in the official documentation. Source-based guidance does not mean OpenViST has run or independently tested this project.
Set up Nlg Eval for command-line evaluation
Install the library and download its required metric data and external code files.
Before you start
- Java 1.8.0 or higher
- Python and the project's Python dependencies
- A Bash-compatible terminal for the documented command-line workflow
Steps
Install the Python package from the project's GitHub repository using the documented pip command.
Run
nlg-eval --setupto download required data and external code files.Prepare hypothesis and reference files with corresponding examples on the same rows.
Run the documented
nlg-evalcommand with the hypothesis file and one or more reference files.
Expected outcome
The command-line tool reports metric values for the aligned generated and reference examples.
Guide limitations
- The README requires Java 1.8.0 or higher.
- On macOS High Sierra or later, the README specifies an environment setting to allow multithreading.
- Windows users outside a Bash terminal may need to locate the
nlg-evalscript.
Sources & review
Source record details
- Source availability
- Active
- Sources checked
- 18 October 2026
- Original website title
- Maluuba/nlg-eval · Official homepage title · retained in its source language

