It's important to understand the incidence rate or predicted incidence rate of a potential survey as it impacts feasibility, fielding time, and cost.
What is Incidence Rate?
Incidence Rate is a measure of the rate of occurrence or the percentage of persons eligible to participate in a study. For example, in a study of American vehicle owners, if the eligibility of research is defined as owning a vehicle, then the IR will be the percentage of Americans who own a vehicle, out of the total number of Americans (meaning out of all Americans, whether they own a vehicle or not).
In other words, to calculate incidence in the contact of market research, the formula is:
The total number of qualified respondents divided by the total number of respondents
who were screened for the study (qualified plus non-qualified).
Estimated vs. Actual IR
The incidence rate range you select from the drop-down is an estimated or predicted IR, once the survey is in field and collecting completes we can determine the actual IR of a survey.
Estimated Incidence Rate
When starting a survey with aytm you can select an estimated incidence rate on the Target Market page. Click the drop-down to choose a range of your predicted incidence rate. If you aren't sure yet, don't worry, this drop-down will also appear on the Survey Editor page, or you can navigate back to the Target Market page at any point while building a survey.
If you plan to use aytm's House Tags to target your study we will provide an IR as we have profiled our panelists by these traits and are familiar with the IR. Read more about House Tags here.
You can use a combination of House Tags and custom screening questions to target your survey.
Custom Pre-Qualification Questions
We provide the flexibility to add custom screening questions, but the system can't predict actual IR until the survey is in field. Generally the more screening questions that are added to a study the lower the overall incidence. When using custom screening questions, use the estimated incidence rate to select your best estimation of your target market.
Remember, the incidence rate is the percentage of people who qualify for your survey after screening questions.
Need help estimating IR?
It's essential to set an estimated IR for a survey, as it will help determine feasibility (can you reach people in your target market), fielding time (how long will it take the survey to complete), and how we manage inviting people from our panel to participate in a survey. If you are not sure, try these methods for estimating IR.
Internal Company Data
Leverage any internal company data to help determine the incidence rate. If applicable, leverage any previous market research, mine your client data, or pick your co-worker's brain.
Google it! If the target is already well researched or a popular topic, it's possible to find statistics on your market after a quick internet search. There are even paid services that have databases of stats to help you determine incidence.
Run an IR test survey
You can run a short survey that uses the exact screening questions you plan to use as regular survey questions. Then launch to the general population, 100-200 respondents is usually sufficient. Then you can filter the results to narrow down who would qualify for your survey to determine the incidence.
Aytm's Predictive Sample Complexity Meter
Aytm's Sample Complexity Meter helps determine the feasibility, turnaround time, and cost for your survey on the fly. When you open a new Target Market page, you will see the Sample Complexity Meter at the top left.
As you set up your targeting criteria by filtering demographic traits and adding screening questions, the Sample Complexity Meter will update in real time.
Above the survey cost, you can see how long your survey will take to complete. If you hover over the N, LOI, and IR, you can see the definitions for each. Each of these contributes to the cost of a survey.
- N, the number of completes
- Sample size
- LOI, length of interview.
- How long it takes a respondent to complete a survey.
- IR, Incidence Rate.
- Percentage of people who qualify for your survey after screening questions.
If you have any questions about determining the incidence rate of your survey, don't hesitate to reach out, start a chat, or email firstname.lastname@example.org for assistance.