How to run a longitudinal study for employees and customers

People’s opinions and preferences change over time.

In the business landscape, where customers and employees are key to the success of every organization, this idea is critical to remember.

To stay on top of people’s changing opinions, it’s best to check in with them consistently and proactively. Survey scientists often refer to this kind of survey technique as a longitudinal study.

In this article, we’ll review best practices for designing a longitudinal study with surveys for your customers and your employees. But first, let’s review the concept in more detail.

What is a longitudinal study?

A longitudinal study is the consistent collection of feedback from the same set of individuals over a period of time.

Running a longitudinal study allows you to accomplish the following:

  • Track changes in people’s opinions and experiences
  • Identify issues on time in order to prevent negative outcomes
  • Discover the right strategies for resolving or improving on a particular area
  • Measure the impact of those strategies by collecting data both before and after changes are made

It’s important to remember that executing a strict longitudinal study is near impossible. People change jobs, customers leave, and workers retire. But if you’re able to keep surveying a sample of people with the same characteristics over time, your study will continue to provide valuable insights.

Best practices for collecting longitudinal data

Here are a few items to keep top of mind before running your longitudinal study:

1) Decide on goals and timelines for meeting them – Think about the specific areas that you hope to influence. Once you’ve picked them out, brainstorm the goals for improving each area and when you should improve them (we’ll use an example to illustrate this point later on)

2) Decide how often you’ll send your surveys – You want to run enough surveys throughout the year to identify issues on time and to effectively capture trends in your data. However, over-surveying recipients can sour your relationship with them and lead to a lower response rate.

Unfortunately, there isn’t a simple one-size-fits-all cadence for sending out your surveys. Each survey should be handled on a case-by-case basis while taking the following rules of thumb into account:

  • The closer the relationship between you and your recipients, the more surveys you can send them (e.g. a manager and her employees)
  • The more often your audience’s opinions are likely to change on a given topic, the more surveys you’ll want to run (e.g. an employee’s level of job satisfaction)

Pro tip: Use the Data Trends feature in SurveyMonkey Analyze to see how your survey responses change over time.

3) Don’t change your questions – Once you send your first survey, hold off on editing your questions. Even small edits can significantly influence your respondent’s answer to a given question, making comparisons across survey touchpoints unreliable.

Learn how to automate your sending surveys using our recurring surveys feature.

With this foundation for collecting longitudinal data in mind, let’s review best practices in running a longitudinal study with key audiences for your organization—beginning with your customers.

Running a longitudinal study of customers

To collect valuable longitudinal data from your customer base, ask yourself the following questions:

  1. Can I segment my customers?
  2. If I can segment them, how should I do it?
  3. For a given segment, how can I define success at every point in time?

You’ll notice a theme in these questions: segmenting your customers, or grouping them based on shared characteristics. Segmenting your customers is fundamental to collecting valuable longitudinal data. It allows you to better personalize your questions and gather more detailed, actionable feedback.

To segment your customers, identify the factors that influence their engagement with you.

Here are a few commonly chosen segments:

  • Level of spend
  • Specific product/service
  • Goals from using product/service
  • Region
  • Industry

Once you’ve chosen your segments, work towards defining each one’s success at different points in time. This allows your team to better prioritize its efforts and understand whether—and to what degree—each customer is successful.

To review these steps, let’s walk through a scenario:

Say you work at a company that hosts reviews for all types of small businesses, similar to Yelp. Your goal is to make sure that each business sees value from using your platform.

You notice that restaurants are, in general, focused on using their listing to increase the number of people who map out directions to their business. Meanwhile, heating, ventilating and air conditioning (HVAC) businesses want to use theirs for receiving more calls from potential clients.

Given the different goals of these two business types, you create a segment for each.

You’d then survey each segment on a quarterly basis to understand their level of progress. The responses will help to prioritize your team’s efforts as well as align with the type of consultation that each business needs.

The questions for your HVAC businesses can look as follows:

1. How strongly do you agree or disagree with this statement: “I am satisfied with the number of calls I’ve received from your platform during the past 90 days.”

  • Strongly agree
  • Agree
  • Neither agree nor disagree
  • Disagree
  • Strongly disagree

2. In a sentence or two, please describe why you selected that particular level of agreement.

The questions for restaurants would be the same, except the prompt for the first question would use mapped directions instead of calls.

Boost employee engagement with longitudinal data

The costs associated with employing disengaged workers is significant. Unfortunately, it’s a reality for many organizations.

According to Gallup, companies with high employee engagement see a 20% increase in profitability. However, only 13% of employees worldwide consider themselves engaged in their job.

To track and address employee engagement, collect longitudinal data from your entire team.  Longitudinal data allows you to discover areas that need to be addressed, understand changes in employee engagement over time, and measure the impact of any and all of your efforts.

Before running your longitudinal study, consider all of the factors that can influence your employees’ experience. These include:

  • Satisfaction with their work
  • Compensation
  • Work-life balance
  • Seeing a future at your company
  • Collaborating with colleagues

Remember that employee engagement needs to be reviewed both closely and holistically. Each of these areas offers an opportunity to improve your employees’ engagement; while looking at your longitudinal data as a whole tells you whether your employees’ experience is going in the direction you want it to.

Given the complexity of measuring employee engagement, your employee survey can be comprehensive and look like this.

Interested in developing a more robust process for tracking and improving on employee engagement? Explore SurveyMonkey Engage. →

It’s easy to forget that the people who matter to your organization are human. Their opinions, preferences, and expectations change in ways that aren’t always easy to predict. Longitudinal data keeps you informed and enables you to act in ways that are ultimately in the best interest of your clients, employees, and your organization.