Shortlink for Sharing:
Tweet about this on TwitterShare on LinkedInShare on FacebookShare on Reddit

Range Errors Hinder Accurate Results

Posted by .

Productive communication requires that we agree on questions and find consensus on answers. What happens when the way we confirm our understanding doesn’t actually make sense?

That’s the issue that comes to mind with the following snippet from an online driving test. Although you probably haven’t been studying to pass this particular exam, take a look at the question and see if you can detect why this is yet another example of a failed attempt at productive communication and workplace productivity:

business improvement process experts discuss a test

The respondent marked “A” for their answer, but the computer scored this as incorrect. The “right” answer is “D”. But if you think about the question for a moment, it should become clear that this is not logical. If “most collisions occur at speeds less than 40 MPH”, than that means any range of speeds 0-40MPH are also included in the majority of all crashes. In fact, the larger the range, the more collisions will be included!


© Flickr user Martin Lewison

This poorly worded question illustrates a “range error.” This is a common problem in making communication productive. You can easily deduce the intention of the test’s authors. They want new drivers to remember this crucial fact:

Most collisions occur at speeds of less than 40 MPH.

That statistic may be surprising to new drivers. Many would probably assume that most car accidents only occur at high speeds, and might rationalize that they don’t need to pay close attention while driving around the city. That’s probably why this factoid is included in the test. Officials want to clearly communicate that distracted driving can lead to accidents at any speed, and that even routine, low-speed driving can be dangerous if drivers are not careful.

With this objective in mind, it’s easy to rewrite the question to be more effective:

Most collisions occur at ___ to ___ MPH
A. 70-100
B. 50-70
C. 40-50
D. 0-40

The entire point of test questions or surveys is to give useful answers. With the way the original question was written, not only was there confusion, but the correct information wasn’t discovered. With the way we’ve re-written the question, it can actually serve its proper purpose. In the instance of this driver’s test question, all mis-written answer choices do is lead to correct answers being marked incorrect, but if you’re writing survey questions with improper ranges, you could be wasting tons of money and time without yielding any valuable information.

There are an array of errors that can occur when it comes to survey questions, and Cornell University ran through the most common ones.

Measurement Error is error or bias that occurs when surveys do not survey what they intended to measure. This type of error results from flaws in the instrument, question wording, question order, interviewer error, timing, question response options, etc. This is perhaps the most common and most problematic collection of errors faced by the polling industry.

Non-response Error results from not being able to interview people who would be eligible to take the survey. Many households now use voice mail and caller ID to screen calls; other people simply do not want to respond to calls sometimes because the endless stream of telemarketing appeals make them wary of answering. Non-response bias is the difference in responses of those people who complete the survey vs. those who refuse to for any reason. While the error itself cannot be calculated, response rates can be calculated and there are countless ways to do so. The American Association for Public Opinion Research (AAPOR web site) provides recommended procedures for calculating response rates along with helpful tools and related definitions to assist interested researchers.

This lesson on productive communication doesn’t just apply to people who write driving tests. Any organization that has crucial facts about their business plan, internal policies, or standard procedures should ensure that they communicate in a way that is consistent with their objectives.

If you find that people make implementation mistakes at your company, take a look at your internal communication. You may be writing or speaking in ways that inadvertently create range errors. These communication issues are a common problem that our organizational productivity specialists help companies face. To learn more, contact our business consulting Indianapolis firm today!

Tweet about this on TwitterShare on LinkedInShare on FacebookShare on Reddit