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The Length of Interview (LOI) Estimation feature provides an estimated completion time for your questionnaire. This estimate helps you understand how long respondents are likely to spend completing the survey before it is published. The estimated interview length is useful for:
  • Planning data collection projects
  • Estimating respondent engagement
  • Managing survey budgets and incentives
  • Selecting the appropriate service tier
  • Identifying questionnaires that may be too long for respondents
Note: The LOI is an estimate only. Actual completion times may vary depending on respondent behavior, questionnaire complexity, device type, language, and other factors. It should be used as a planning guide rather than a guaranteed interview duration.

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How LOI Estimation Works

When you select a Data Collection Method in the Questionnaire Metadata section, VoxDash automatically assigns a default completion time to each question type. These default times are based on the selected collection method because respondents interact with surveys differently depending on how the data is collected. For example, completing a web-based questionnaire may require a different amount of time than participating in an interviewer-assisted survey. The system combines these default values with your questionnaire structure to calculate the estimated interview length.

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Accessing the LOI Settings

You can configure the LOI estimation from the Editor Panel. To access the feature:
  1. Open your questionnaire in the Editor Panel.
  2. Locate the Properties Panel on the right side of the screen.
  3. Expand the LOI (Length of Interview) section.
The LOI panel contains two main areas:
  • Estimation Settings
  • Interview Length Estimation

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Estimation Settings

The Estimation Settings section allows you to customize how the interview length is calculated. These settings help produce a more realistic estimate by accounting for factors that may affect how long respondents take to answer your questionnaire.

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Time Adjustment

The Time Adjustment settings allow you to fine-tune the calculation based on the expected characteristics of your survey and respondents. The available adjustment factors include:

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Language Multiplier

Adjusts the estimated completion time based on the language of the questionnaire. Some languages naturally require more or less reading time, which can affect the overall interview length. Example: A translated questionnaire may require additional reading time compared to the original version.

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Respondent Complexity Multiplier

Adjusts the estimate according to the expected respondent profile. Respondents with specialized knowledge, technical expertise, or complex decision-making processes may require more time to answer questions accurately. Example:
  • General consumers may complete the survey quickly.
  • Industry professionals or business decision-makers may take longer to evaluate each question.

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Topic Complexity Multiplier

Adjusts the interview length based on how difficult or technical the survey content is. Simple questionnaires generally require less time, while surveys covering technical, financial, healthcare, or analytical topics may increase completion time. Example: A customer satisfaction survey typically takes less time than a detailed product research questionnaire.

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Average Path Percentage

Not every respondent answers every possible question. Branching logic, skip logic, and display conditions often cause respondents to follow different paths through a questionnaire. The Average Path Percentage estimates how much of the questionnaire an average respondent is expected to complete. This helps produce a more realistic LOI by accounting for conditional question flows. Example: If most respondents answer only 70% of the available questions due to skip logic, the estimated interview length will be based on that average path rather than the full questionnaire.

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Interview Length Estimation

The Interview Length Estimation section displays the calculated interview duration based on the current questionnaire configuration. The estimate considers:
  • The selected data collection method
  • The number of questions in the questionnaire
  • The types of questions used
  • The default completion time for each question type
  • Your custom LOI settings and adjustment factors
As you modify your questionnaire or update the estimation settings, the interview length is recalculated automatically.

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Customizing Question Timing

After selecting a Data Collection Method, VoxDash displays the default estimated completion time for each available question type. These values are provided by the system as recommended defaults based on typical respondent behavior. If your questionnaire requires more or less time than the default estimate, you can manually adjust the expected duration for each question type. For example, you may choose to increase the estimated time for:
  • Long Text questions that require detailed written responses.
  • Dynamic Panels containing multiple repeated questions.
  • Complex Matrix questions with many rows and columns.
Likewise, you can reduce the estimated time for simple Yes/No or single-choice questions if they are expected to be answered quickly. These custom timings are incorporated into the overall LOI calculation, allowing the estimate to better reflect your specific questionnaire.

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Best Practices

To produce the most accurate interview length estimate:
  • Select the appropriate Data Collection Method before reviewing the LOI.
  • Review the default timing values for each question type.
  • Adjust question timings only when your questionnaire differs significantly from typical surveys.
  • Configure the estimation multipliers to match your target audience and survey complexity.
  • Recheck the estimated interview length after adding, removing, or modifying questions.
Keeping your LOI estimate up to date helps ensure better project planning, improves respondent experience, and supports more accurate budgeting and operational decisions.