MA-sLDAc is a C++ implementation of the supervised topic models with labels provided by multiple annotators with different levels of expertise, as proposed in:

• Rodrigues, F., Lourenço, M, Ribeiro, B, Pereira, F. Learning Supervised Topic Models for Classification and Regression from Crowds. IEEE Transactions on Pattern Analysis and Machine Intelligence (TPAMI), 2017.
• Rodrigues, F., Lourenço, M, Ribeiro, B, Pereira, F. Learning supervised topic models from crowds. The Third AAAI Conference on Human Computation and Crowdsourcing (HCOMP), 2015.

The code is based on the supervised LDA (sLDA) implementation by Chong Wang and David Blei (http://www.cs.cmu.edu/~chongw/slda/). Three different variants of the proposed model are provided:

• MA-sLDAc (mle): This implementation uses maximum likelihood estimates for the topics distributions (beta) and the annotators confusion matrices (pi);
• MA-sLDAc (smooth): This implementation places priors on beta and pi and performs approximate Bayesian inference;
• MA-sLDAc (svi): This implementation is similar to the “MA-sLDAc (smooth)”, but uses stochastic variational inference.

For simplicity reasons, I recommend first-time users to start with "MA-sLDAc (mle)", since this version has less parameters that need to be specified.

A version of this model for regression tasks is available here.

Sample multiple-annotator data using the 20newsgroups dataset is provided here. More datasets are available here.

Copyright (c) 2015 Filipe Rodrigues

This program is free software. You can redistribute it and/or modify it under the terms of the GNU General Public License, version 3, as published by the Free Software Foundation.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

Appropriate reference to this software should be made when describing research in which it played a substantive role, so that it may be replicated and verified by others.

Type "make" in a shell.

Please note that this code requires the Gnu Scientific Library, http://www.gnu.org/software/gsl/

Usage:

./maslda est [data] [answers] [settings] [alpha] [k] [random/seeded/model_path] [seed] [directory]

Data format:

• [data] is a file where each line is of the form: [M] [term_1]:[count] [term_2]:[count] ... [term_N]:[count], where [M] is the number of unique terms in the document, and the [count] associated with each term is how many times that term appeared in the document.
• [answers] is a file where each line contains the labels of the different annotators (separated by a white space) for [data]. Each column therefore corresponds to all the answers of an annotator. The labels must be 0, 1, ..., C-1, if we have C classes. Missing answers are encoded using "-1".

Example:

./maslda est ../20newsgroups/data_train.txt ../20newsgroups/answers.txt settings.txt 0.1 5 random 1 output

Usage:

./maslda inf [data] [labels] [settings] [model] [directory]

Data format:

• [labels] is a file where each line is the corresponding true label for [data].

Example:

./maslda inf ../20newsgroups/data_test.txt ../20newsgroups/labels_test.txt settings.txt output/final.model output

The settings file specifies the following parameters:

• "labels file" is a file with the true labels for the training documents. If a valid file is provided, it will be use to compute and report error statistics during the model estimation.
• "pi estimate" or "pi fixed" determines whether of not the confusion matrices of the different should be estimated or kept fixed to the values provided by "pi file".
• "pi file" is a file with the true confusion matrices of the multiple annotators. If a valid file is provided, it will be use to compute and report error statistics during the model estimation.
• "pi laplace smoother" and "lambda laplace smoother" define the values of the laplace smoothers used when estimating pi and lambda respectively.