This is an old revision of the document!
Table of Contents
Addicter
Addicter stands for Automatic Detection and DIsplay of Common Translation ERrors. It will be a set of tools (mostly scripts written in Perl) that help with error analysis for machine translation.
The work on Addicter has started at the MT Marathon 2010 in Dublin, within a broader 5-day project called Failfinder (Dan Zeman, Ondřej Bojar, Martin Popel, David Mareček, Jon Clark, Ken Heafield, Qin Gao, Loïc Barrault). The code that resulted from the project can be freely downloaded from https://failfinder.googlecode.com/svn/trunk/. The nucleus that existed just after the MT Marathon (4 Feb 2010) is Addicter version 0.1, to reflect that this is by no means deemed a final product. Anyway, it can already do a useful job.
Currently, Addicter can view and browse aligned corpora, look for example words in context and summarize known alignments of a given word. The viewing and browsing is performed using a web server that generates web pages dynamically (to avoid pre-generating millions of static HTML documents). The obvious drawback is that access to a web server is needed.
Installation
- Install a web server, unless you already have access to one (local or remote). For instance, the Apache web server is available for at least Linux and MS Windows, and it's free. Configure your web server to work with CGI scripts written in Perl.
- To be able to generate alignments that will be displayed by Addicter, you need Giza++ or equivalent. The first training few steps of the Moses suite will do.
- Check out Addicter code from the Failfinder SVN repository.
How to install and configure Apache
This tutorial currently focuses on installing Apache HTTP Server on Microsoft Windows. If you are experienced user of another operating system and wish to share advice, please feel free to contact me.
- Download the Apache HTTP Server from http://httpd.apache.org/download.cgi. For MS Windows, you can download a package for the Microsoft Installer (
.msi
). Install it by double-clicking on the installation file. I suggest installing Apache as a system service. That way, it will automatically start on startup of your computer. - Configure the server. This essentially means editing a configuration file and restarting the server. Depending on your system settings, Apache version etc., the configuration file will reside in a path similar to this:
C:\Program Files\Apache Software Foundation\Apache2.2\conf\httpd.conf
. Alternatively, you can access it via your Start Menu: Apache → Apache HTTP Server 2.2 → Configure Apache Server → Edit the Apache httpd.conf Configuration File.- Look for a
ScriptAlias
directive. It tells the server: 1. what path on the hard disk contains scripts that can generate dynamic HTML content on the fly, and 2. how the path will be represented in the URL (web address). For exampleScriptAlias /cgi/ "C:/Documents and Settings/Dan/Documents/Web/cgi/"
says that the URL
http://localhost/cgi/anyscript.pl
leads to your scriptC:\Documents and Settings\Dan\Documents\Web\cgi\anyscript.pl
, and that it's a script (i.e., the server shall invoke it and send its output, instead of sending the script itself). - Under Windows, you will also want to set
ScriptInterpreterSource registry
It tells the server that the Windows registry shall be used to figure out how to run a script (e.g., that
C:\Perl\Perl.exe
binary must be run to interpret a.pl
script).
- Restart the server. On the main Windows panel, there is (typically in the lower right corner) a set of icons, including a new one for Apache. Right-click on it, select Open Apache Monitor, then Restart.
Alignment viewer
Before invoking the viewer, you need to run an indexing script over your aligned corpus. It will create a bunch of index files that will later tell the viewer where to look for examples of a particular word. The indexer needs the following input files:
train.src
… source side of training corpustrain.tgt
… target side of training corpustrain.ali
… alignment of training corpustest.src
… source side of test datatest.tgt
… reference translation of test datatest.ali
… alignment of the source and reference translation of test datatest.system.tgt
… system output for test datatest.system.ali
… alignment of the source and the system output for test data
The indexer splits the output index into multiple files in order to reduce size of any individual file. All index files must be stored in the same folder as the viewing CGI scripts.