Custom Question Answering

Bot Framework v4 Custom question answering bot sample. This sample demonstrates usage of advanced features of Custom question answering like Precise answering, support for unstructured sources along with Multi-turn conversations and Active Learning in a bot.

This bot has been created using Bot Framework, it shows how to create a bot that uses the Custom question answering feature in Language Service.

Concepts introduced in this sample

The Custom question answering feature in Language Service enables you to build, train and publish a simple question and answer bot based on FAQ URLs, structured and unstructured documents or editorial content in minutes. In this sample, we demonstrate:

  • How to use the Active Learning to generate suggestions for knowledge base.
  • How to use follow up prompts to create multiple turns of a conversation.
  • How to configure display of precise answers.
  • How to enable/disable querying unstructured sources with the bot.


Configure knowledge base of the project

  • Follow instructions here to create a Custom question answering project. You will need this project’s name to be used as ProjectName in appsettings.json.
  • Visit Language Studio and open created project.
  • Go to Edit knowledge base -> Click on ... -> Click on Import questions and answers -> Click on Import as TSV.
  • Import SampleForCQA.tsv file.
  • You can test your knowledge base by clicking on Test option.
  • Go to Deploy knowledge base and click on Deploy.

Connect your bot to the project.

Follow these steps to update appsettings.json.

  • In the Azure Portal, go to your resource.
  • Go to Keys and Endpoint under Resource Management.
  • Copy one of the keys as value of LanguageEndpointKey and Endpoint as value of LanguageEndpointHostName in appsettings.json.
  • ProjectName is the name of the project created in Language Studio.

To try this sample

  • Install the Bot Framework Emulator version 4.14.0 or greater from here

  • Run the bot from a terminal or from Visual Studio, choose option A or B.

    A) From a terminal

    # run the bot
    dotnet run

    B) Or from Visual Studio

    • Launch Visual Studio
    • File -> Open -> Project/Solution
    • Select QnABot.csproj file
    • Press F5 to run the project
  • Connect to the bot using Bot Framework Emulator

    1. Launch Bot Framework Emulator
    2. File -> Open Bot
    3. Enter a Bot URL of http://localhost:3978/api/messages

Try Active Learning

  • Try the following utterances:
    1. Surface Book
    2. Power
  • In Language Studio, click on inspect to see the closeness in the scores of the returned answers.
  • In Bot Framework Emulator, a card is generated with the suggestions.
    • Clicking an option would send a feedback record which would show as suggestion under Review suggestions in Language Studio.
    • ActiveLearningCardTitle, ActiveLearningCardNoMatchText and ActiveLearningCardNoMatchResponse in the card could be changed from QnAMakerBaseDialog.cs.

Try Multi-turn prompt

  • Try the following utterances:
    1. Accessibility
    2. Options
  • You will notice that multi-turn prompts associated with the question are also returned in the responses.

Try Precise Answering

  • Try the following utterances:
    1. Accessibility
    2. Register
  • You will notice a short answer returned along with a long answer.
  • If testing in Language Studio, you might have to check Include short answer response at the top.
  • You can disable precise answering by setting EnablePreciseAnswer to false in appsettings.json.
  • You can set DisplayPreciseAnswerOnly to true in appsettings.json to display just precise answers in the response.
  • Learn more about precise answering.

Query unstructured content

  • Go to your project in Language Studio -> In Manage sources click on + Add source
  • Click on URLs and add and select unstructured in the Classify file structure dropdown.
  • Try the following utterances:
    1. Frontline workers
    2. Hybrid work solutions
  • You can observe that, answers are returned with high score.
  • You can set _includeUnstructuredSources to false in QnAMakerBaseDialog.cs to prevent querying unstructured sources.

Try Filters

  • Go to your project in Language Studio -> In Edit knowledge bases -> Under Metadata column click on + Add
  • Select a QnA to edit and add a key value pair, say Language : CSharp, and click on Save changes.
  • Click on Test and select metadata that you just added(Language : CSharp) by clicking on Show advanced options.
  • This will return answers with specified metadata only.
  • You can filter answers using bot as well by passing metadata and/or source filters. Edit line no. 81 in QnAMakerBaseDialog.cs to something like below. Learn more.

    var filters = new Filters
        MetadataFilter = new MetadataFilter()
            LogicalOperation = Bot.Builder.AI.QnA.JoinOperator.AND.ToString()
        LogicalOperation = Bot.Builder.AI.QnA.JoinOperator.AND.ToString()
    filters.MetadataFilter.Metadata.Add(new KeyValuePair<string, string>("Language", "CSharp"));
    // Initialize Filters with filters in line No. 81

Microsoft Teams channel group chat fix

When a bot (named as HelpBot) is added to a Teams channel or Teams group chat, you will have to refer it as @HelpBot How to build a bot? to get answers from the service. However, bot tries to send <at>HelpBot</at> How to build a bot? as query to Custom question answering service which may not give expected results for question to bot. The following code removes <at>HelpBot</at> mentions of the bot from the message and sends the remaining text as query to the service.

  • Goto Bots/QnABot.cs
  • Add References

    using Microsoft.Bot.Connector;
    using System.Text.RegularExpressions;
  • Modify OnTurnAsync function as:

    public override async Task OnTurnAsync(ITurnContext turnContext, CancellationToken cancellationToken = default)
            // Teams group chat
            if (turnContext.Activity.ChannelId.Equals(Channels.Msteams))
                turnContext.Activity.Text = turnContext.Activity.RemoveRecipientMention();
            await base.OnTurnAsync(turnContext, cancellationToken);
            // Save any state changes that might have occurred during the turn.
            await ConversationState.SaveChangesAsync(turnContext, false, cancellationToken);
            await UserState.SaveChangesAsync(turnContext, false, cancellationToken);

Deploy the bot to Azure

See Deploy your C# bot to Azure for instructions.

The deployment process assumes you have an account on Microsoft Azure and are able to log into the Microsoft Azure Portal.

If you are new to Microsoft Azure, please refer to Getting started with Azure for guidance on how to get started on Azure.

Further reading


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