PART II — DESIGN THE DATASET

5. Choose Scripted vs Unscripted Collection

5.1 Scripted Collection

Participants read prepared sentences.

a) Use scripted data when you need:

• Consistent text/audio pairs

• Controlled vocabulary

• Sentence-level alignment

• Clear transcription

• Specific words or phrases

• Named entities

• Domain-specific terminology

b) Advantages

• Fast to collect

• Easy to validate

• Predictable content

• Easy to align with text

c) Limitations

The reference report notes that scripted speech can omit natural speech phenomena such as:

• Fillers

• False starts

• Slang

• Code-switching

• Natural prosody

• Informal speech

It can also introduce bias toward formal language.

6. Unscripted Collection

Unscripted collection asks contributors to speak naturally in response to a prompt.

For example:

“Describe what you normally do when you wake up in the morning.”

or:

“Tell us about a memorable journey you have taken.”

or:

Show an image and ask the participant to describe what is happening.

The reference project used both text and image prompts to elicit spontaneous speech.

Advantages

Captures:

• Natural phrasing

• Accent

• Dialect

• Spontaneous speech

• Informal vocabulary

• Prosody

• Natural discourse

Challenges

Unscripted recordings require substantially more:

• Validation

• Transcription

• QA

• Prompt design

• Human review

The reference project therefore used a multi-level QA and transcription process for this data.

7. Decide Your Domains

Do not collect speech around one topic only.

The reference project used multiple domains, including:

• Agriculture and Food

• Everyday Scenarios

• Financial Transactions

• Digital Government Services

• Named Entity Recognition

• Role Play

• Extempore Stories

• Healthcare

• News and Media

• Education and Technology

• Customer Care

Create your own domain matrix

The purpose is to expose the eventual model to varied vocabulary and contexts.

8. Develop Your Scripted Sentences

Your scripted sentences should not simply be random translations.

Build them from:

• Existing corpora

• Existing language resources

• Domain-specific material

• Locally generated sentences

• Carefully reviewed translations

The reference project combined existing corpora with translated and newly generated material.

Every sentence should be checked for:

• Naturalness

• Correct grammar

• Correct spelling

• Correct terminology

• Cultural appropriateness

• Dialect

• Names

• Places

• Numbers

• Dates

• Abbreviations

Important rule

Do not assume an English sentence can simply be translated word-for-word.

The reference project specifically encountered problems with polysemous words, inconsistent translations and concepts that lacked direct equivalents in some languages.

9. Develop Unscripted Prompts

Good prompts produce speech.

Bad prompt:

“Do you like farming?”

Possible response:

“Yes.”

Good prompt:

“Tell us about the farming activities that people in your community usually do during the rainy season.”

This encourages a longer response.

Use several prompt types

a)Text prompts

A written question.

b) Image prompts

An image plus a question.

c) Story prompts

Ask participants to tell a story.

d) Scenario prompts

Ask participants to explain what they would do.

e) Role-play prompts

Example:

“Imagine you are calling a customer-care agent because your mobile money transaction failed.”