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Transcription - RSA English

Welcome to our model card for RSA English Transcription. This model card describes our currently deployed transcription model available via our API and the Playground.

Model Card

*Basic information about the model: Review section 4.1 of themodel cards paper.

OrganizationLelapa AI
ProductVulavula
Model date21 September 2023
FeatureASR
LangSouth African English
DomainCall Center
Model NameLelapa-X-ASR (ZA-English)
Model version1.0.0
Model TypeFine-Tuned Proprietary Model

Information about training algorithms, parameters, fairness constraints or other applied approaches, and features: Proprietary Fine-tuning of a Base Model on Transcription Data

License: Proprietary

Contact: info@lelapa.ai

Intended use

Use cases that were envisioned during development: Review section 4.2 of model cards paper.

Primary intended uses

Intended use is governed by language and domain of the model. Model is intended to be used in the call center domain for transcription of calls that are conducted in South African English. The model is not suitable for general conversation domain and should be used with extreme caution in high risk environments.

Primary intended users

Transcription to enable analysis for downstream tasks in the call center domain for South African English:

  • Compliance monitoring for customer Interactions
  • Quality assurance
  • Enabling search and filter of conversations

Out-of-scope use cases

All domains and languages outside of the call center analytics space for South African English.

Factors

Factors could include demographic or phenotypic groups, environmental conditions, technical attributes, or others listed in Section 4.3: Review section 4.3 of model cards paper.

Relevant factors

Groups:

  • Users who recorded utterances used to train the model are diverse across several factors such as age, location (primarily South Africa but from several regions/parts of the country depending on the language), and gender (both males and females are equally distributed across speakers). There is no record of the social class of speakers, as well as their health conditions, names, and any other sort of privacy details. Further details of groups and their constituents can be found in the datasheet.
  • Performance across groups is underway.

Environmental conditions, Instrumentation & Technical attributes:

  • Audio utterances are recorded in environments such as rooms, and call centers with a noiseless background.
  • Audio segments’ length varies from 3 seconds to 30-40 minutes.

Evaluation factors

  • In our development setting (training and evaluation) we used the factors described above with additional synthetic arrangements to improve robustness of the model to real world factors.

Metrics

The appropriate metrics to feature in a model card depend on the type of model that is being tested. For example, classification systems in which the primary output is a class label differ significantly from systems whose primary output is a score. In all cases, the reported metrics should be determined based on the model’s structure and intended use: Review section 4.4 of model cards paper.

Model performance measures

The model is evaluated using WER as well as human evaluation: The models’ performances are measured by both automatic metrics and human evaluation. As an automatic metric, we use the Word Error Rate (WER) which is based on the edit distance also called Levenshtein distance. WER is not a symmetric distance metric, since it measures the number of operations: substitution, deletion, insertion, number of correct words needed to leave a reference sentence A to a predicted sentence B. Read more. As far as human evaluation is concerned, this stage is performed by paid linguists or native speakers of the languages under study.

WER: Testing on general South African English data (incl call center)

Decision thresholds

No decision thresholds have been specified.

Approaches to Uncertainty and Variability

For fairness, robustness, and generalization with respect to languages and datasets, we leveraged standard downsampling and normalization techniques which have proven to be useful.

Evaluation data

All referenced datasets would ideally point to any set of documents that provide visibility into the source and composition of the dataset. Evaluation datasets should include datasets that are publicly available for third-party use. These could be existing datasets or new ones provided alongside the model card analyses to enable further benchmarking. Review section 4.5 of model cards paper.

Datasets

  • Publicly available datasets in the general domain
  • Proprietary call center dataset

Motivation

These datasets have been selected because they are open-source, high-quality, and cover the targeted languages - and utterances are recorded by a variety of speakers living in required regions. These help to capture interesting cultural and linguistic aspects that would be crucial in the development process for better performance.

Preprocessing

Data utterances are filtered initially by audio length, sampled, and transcripts normalized. We also make sure to select actual recordings i.e. recordings that are not just noise or blank.

Training data

Review section 4.6 of model cards paper.

Refer to the datasheet provided

Quantitative analyses

Quantitative analyses should be disaggregated, that is, broken down by the chosen factors. Quantitative analyses should provide the results of evaluating the model according to the chosen metrics, providing confidence interval values when possible. Review section 4.7 of model cards paper.

Unitary results

WER
WER ZA English (General and Call Center)0.0869

Human evaluation

This is a breakdown of the types of errors we are seeing based on a sample of the evaluation dataset.

*Note: some samples suffered from more than 1 type of error

ZA EnglishYesNoTotal
Transcription Correct97299
Prediction Correct91899
Ambiguous Audio Input41
Context-Breaking1
Flawed Audio Input1
Homophone
Name, Anglicism, Loan Word
Non-context-Breaking4
Flawed Ground Truth Transcript1
Negligible2

Intersectional result

In progress

Ethical considerations

This section is intended to demonstrate the ethical considerations that went into model development, surfacing ethical challenges and solutions to stakeholders. The ethical analysis does not always lead to precise solutions, but the process of ethical contemplation is worthwhile to inform on responsible practices and next steps in future work: Review section 4.8 of model cards paper.

All call center data is synthetic and so the model does not contain any personal information. More details in the datasheet.

Caveats and recommendations

This section should list additional concerns that were not covered in the previous sections. Review section 4.9 of model cards paper.

Additional caveats are outlined extensively in our Terms and Conditions.