When you run an online survey it is always useful to check the length of interview, or LOI. That’s because very often it will be lower than you expected. This is particularly likely if you are using a panel for sample, rather than a customer database for example. If your survey LOI is lower than expected that can be an advantage for you.
What is LOI?
The LOI is the average amount of time taken by respondents to complete a questionnaire. It is usually measured in seconds or minutes, and automatically recorded by most online survey software tools. So whoever is hosting your survey should be able to easily provide it to you.
Questions per minute
Typically, the market research industry works on the assumption of survey respondents answering 3 questions a minute (assuming a mix of question types, including some grids). So if your questionnaire has 15 questions then this would be expected to have a 5 minute LOI.
Value of LOI data
Ideally when you run an online survey you would be provided with the LOI data from the soft launch. In other words, at an early stage, before the main fieldwork begins. Once you see the LOI you will be able to determine how it compares with your expectations, and with the LOI that you paid for. In other words, if you are running an online survey through a panel then you will probably have specified the LOI in advance.
If the LOI is lower than expected, you have several options. These include:
- requesting a lower fee from your supplier for the sample
- requesting a higher sample size for no increase in fee
- asking your provider to put some measures into the questionnaire to slow down respondents at certain questions
- adding further questions to the questionnaire
So LOI is a useful measure to keep an eye on.