Diving Into Longitudinal Surveys

Diving Into Longitudinal Surveys

longitudinal surveys

Longitudinal surveys are the most powerful assets that marketers and market researchers can use when conducting longitudinal research. 

We’ve previously highlighted the three main types of survey research methods, which include cross-sectional studies, longitudinal studies and retrospective studies. In this article, we will cover longitudinal surveys and their underlying studies.

You can apply longitudinal studies for a wide range of verticals and purposes. As such, it is crucial to learn about this research method so that you can set it off smoothly for your survey research needs. 

Defining Longitudinal Surveys

A longitudinal study is defined as a study in which researchers gather data on the same set of variables (respondents) over a period of time. This kind of research grants researchers the ability to closely examine the trajectories and changes of their subjects over time.

This study includes gathering insights on the sample pool’s opinions, behaviors, sentiments, desires, reactions and several other aspects. Mostly used in medical and social sciences, this form of research is also invaluable for brands, as studying your target market is key to keeping your business alive.

A form of correlational research, researchers (and businesses) conduct longitudinal research via collecting data on a group of variables without influencing or affecting the variables in any way. Each data collection is called a wave.

It is optimal to conduct this kind of study via longitudinal surveys, as they are designed to garner all the questions you need and to create them in innovative ways.

The Key Aspects of Longitudinal Surveys

To fully understand longitudinal surveys, you should peruse some of their key features. This will help you understand their make up and decide whether to use them for your survey research.

The following lists the core facets that distinguish these surveys from that of others. Here is how they differ aside from their deployment frequency:

  1. These studies and their surveys gather insights over long-term periods.
  2. Despite being typically used for a long period of time, there is no fixed amount of time required to constitute a longitudinal study.
  3. These studies can range from several weeks to years and even decades.
  4. They are part of observational studies, in which no intervention takes place, only pure investigation.
  5. They involve repeated observations of the same group of participants.
  6. They are used to uncover relationships between variables that are not connected to background variables. 
  7. They are used to discover how the sampling pool (respondents) changes over time.
  8. They are used after extracting some findings from cross-sectional studies, when those studies warrant more data and inquiry. 
  9. They collect both quantitative and qualitative data.
  10. They can be conducted through primary research, along with secondary research.
    1. Primary sources: surveys, survey panels, interviews, focus groups
    2. Secondary sources: government websites, focused reports, ex: longitudinal studies on American youth

How They Differ from Cross-Sectional & Retrospective Surveys

longitudinal study

Longitudinal studies are often contrasted with cross-sectional studies. They also differ from retrospective studies. The survey of each study follows suit, as it will be distinguished in design, function and deployment frequency. 

Unlike longitudinal studies, cross-sectional studies involve examining samples of a given population (the cross-section) at a particular point in time. The surveys in this research method paint a snapshot of a sampling pool, usually the prevailing one.

As such, cross-sectional studies are far shorter to conduct. They are often used as precursors to longitudinal studies, in that they discover correlations that can be further probed longitudinally. 

Retrospective studies combine aspects of both cross-sectional and longitudinal studies. They study respondents with surveys about past events. Researchers can thus compare past feelings and attitudes with those of the present, much like in longitudinal studies. In this way, these studies are used hand in hand with longitudinal studies, despite that retrospective studies form their own distinct set of research.

Retrospective surveys can be conducted just once, as are cross-sectional surveys. They may also amass data on several points in time. These surveys draw from a pool of an already existing data set.

As such, retrospective studies only deal with events of the past and will not gather any new data; that’s where longitudinal studies are needed to be used in tandem with them. 

It’s important to note that all three of these research methods/survey types are observational, allowing researchers to record and understand the subjects’ behaviors via observation only.

The 3 Types of Longitudinal Surveys

types of longitudinal studies

Longitudinal studies can be carried out in various ways. There are three main classifications of longitudinal surveys: a panel study, a cohort study and a retrospective study. As mentioned above, retrospective studies make up their own major form of research. However, due to their close involvement with longitudinal studies, they can also exist as a form of these studies. 

  1. Panel study: 

    1. It involves sampling a prerecruited set of survey respondents.
    2. These respondents agree to a particular length of participation.
    3. Surveys are sent to the exact same group of respondents.

  1. Cohort study: 

    1. It is conducted through online survey software. 
    2. Respondent selection is set by way of shared characteristics, such as a geographical location, births and historical experiences.
    3. It also deals with respondents on the basis of demographics and opinions and behaviors (the latter two are collected via screening questions).

  1. Retrospective study: 

    1. It uses past information on the same or similar subjects (variables).
    2. It involves studying the past with recorded data. Ex: medical records, past surveys.
    3. It complements any current or soon-to-be gathered longitudinal data. 

The first two types of surveys are part of prospective longitudinal research, in which a sampling pool is studied over a period of time. They therefore fall opposite to retrospective studies.

Which Industries Depend on these Surveys for Market Research

There are several industries that utilize longitudinal surveys for market research undertakings. These surveys, therefore, provide a wide variety of applications. The following list details the various verticals that rely on longitudinal surveys.

  1. Healthcare: Physicians, other healthcare providers and researchers can study any biological change in participants in terms of their lifestyle, i.e., their diets, their fitness/ sedentary habits, health upkeep, reactions to medicines and much more.
  2. Retail: Retailers can study shopping habits from time to time and discover how advancements in the sectors affect those habits or form new ones.
  3. Psychology: Psychologists can conduct these surveys to study how the mentality and psyche of various groups change over time in reaction to stimuli or any change. 
  4. Education: Those in the education sector can use students' test scores, work and products to track developments over time. Monitoring student progress can also identify disparities in academic performance levels among students.
  5. Real estate: Real estate agents and business owners can use these surveys to gather opinions of residents and businesses within a neighborhood or property over time. 
  6. Technology: Tech leaders and manufacturers can learn how consumers change or develop certain behaviors due to the use of existing technology or the emergence of new kinds.
  7. General business: Brands can conduct these surveys to closely monitor their target market, especially in relation to their products. Additionally, businesses can study closely associated target markets or even different knees to gain new patrons. 

Types of Business Surveys that Rely on Longitudinal Studies

Dovetailing onto the final industry using longitudinal data, that of general business, it is crucial to understand just the kinds of surveys that brands can use. This is because a wide array of survey types (based on the subdisciplines of business) can be applied in longitudinal studies. Here are a few key survey types:

  1. Marketing market research: Brands can use marketing surveys for market research to study trends in the market and within niches firsthand. They can also help businesses capture demand for their product/service, along with measuring campaign success. 
  2. Customer Satisfaction: A major component of any business, there are a variety of surveys for this purpose, such as the Net Promoter Score (NPS), Customer Satisfaction Score (CSAT) and the Customer Effort Score (CES).
  3. Product feedback: These surveys provide necessary insight into the sentiment around product launches or existing products, should you want to test their levels of customer contentment. You can test for usability, awareness and general opinions on your products via longitudinal feedback.
  4. Employee engagement: Not all survey research is external, not even when it comes to the longitudinal variety. As such, it is apt for businesses to keep an eye on their employee engagement levels. This involves checking on employees’ comfort on the job and collaboration with others. A longitudinal survey on employee engagement will give you the full scope of your company’s pulse and how to improve it. 

The Pros and Cons of Longitudinal Surveys

Longitudinal studies, like others, come with their own sets of benefits and stumbling blocks. You ought to consider both sides in order to get the full picture on this kind of research method. Understanding the pros and cons will help you determine whether it is worth using this kind of study and its accompanying survey(s). It will also keep you aware of what to expect. 

Pros

  1. Longitudinal surveys allow you to monitor your target market and general sampling pool in real time. This allows you to place all insights sequentially and be able to correlate events with causes.
  2. This is the only study that gives you access into observing developments and life-spanning issues.
  3. These surveys allow you to study hypotheses conjectured at cross-sectional surveys to learn more and form educated decisions.  
  4. This is the most optimal study for identifying causal relationships and cause and effect.
  5. It stamps out the risk of recall bias, which denotes the inability to remember past occurrences.
  6. It can be used within a variety of survey types and industries including ones not mentioned above such as advertising, community feedback and more.
  7. They allow you to discover which sentiments and behaviors are conditional and which withstand the test of time. 

Cons

  1. These are the most time-consuming surveys; they may not work alongside other surveys since they’re results aren’t complete until the end of the studied period.
  2. They require the most resources and are the most expensive kind of survey to conduct.
  3. Respondents may drop off over time, as not all are going to be as committed to the study. This is known as selective attrition. 

Beyond Market Research: Longitudinal Studies as Content Assets

Longitudinal studies take the most amount of dedication and commitment — both on the end of the researchers and respondents due to their time-consuming nature. Nonetheless, they are valuable sources of primary research.

For businesses, these kinds of surveys do far more than just provide firsthand insights and data. Marketing teams can delight in that conducting longitudinal studies provides an invaluable content marketing asset, the kind that will easily distinguish a brand from its competitors.

Many businesses rely on content to increase brand awareness and gain leads. In fact, 60% of marketers produce one piece of content per day to grow their business. There are brands that use it to boost their user experience (UX) and even retain their customers. While blogs and social posts are typical, a longitudinal study is a downloadable asset worth conducting. It may be enlightening enough to gain media attention. 

Frequently asked questions

What are the three main types of survey research methods?

The three main types of survey research methods are longitudinal studies, cross-sectional studies, and retrospective studies.

Why are longitudinal surveys performed?

A longitudinal survey is one that is created in order to gather data from respondents over a period of time. Surveys are distributed multiple times to the same group of respondents in order to study how specific variables change over time.

Why are longitudinal surveys performed?

The purpose of a longitudinal survey is to understand how a group’s behaviors, opinions, feelings, needs, and desires change over a period of time.

How does a longitudinal study differ from a cross-sectional study?

Cross-sectional studies provide a snapshot of the sample pool at a specific point in time, while longitudinal studies provide many snapshots of the sample pool at specific points over a period of time.

What are the three types of longitudinal studies?

The three types of longitudinal studies are panel studies, cohort studies, and retrospective studies.

by lorraine

All About Panel Surveys: Using this Method for Market Research

All About Panel Surveys: Using this Method for Market Research

Panel surveys (not to be confused with survey panels) are used in survey research as part of longitudinal studies. The purpose of this kind of study is to reap continual observations on different variables on the same sample pool over a period of time. 

The variables include consumer feelings, attitudes and opinions regarding a number of matters. As such, the surveys are conducted across the same sample pool, i.e., the survey panel.

This way, the opinions of the same panelists can be monitored, as opposed to bringing in new respondents (even if they are part of the same target market). Panel surveys are conducted in waves (sequences of surveys) to measure changes in consumer thoughts and behaviors. 

There are many key aspects of panel surveys; this article will cover all of them to help you decide on whether your business needs to use the panel survey method.

How Panel Surveys are Conducted

First off, panel surveys are but one type of longitudinal studies, which also include retrospective studies and record linkages.

As their name indicates, panel surveys use surveying as the data collection method. This data is mainly collected through the aforementioned survey panels, a method in which a pre-recruited pool of respondents agreed to take part in your survey.

However, panel surveys can also be collected through other online survey methods, mainly DIY survey platforms. These allow you to target a specific set of respondents, but unlike survey panels, they are not conducted among the same exact group of individuals. (More on this below).

Since panel surveys are longitudinal, this sampling pool stays the same and is used for repeated studies and observations.

Panel surveys are part of panel research and can take the form of either qualitative or quantitative studies for measuring consumer behavior. 

The Pros of Panel Surveys

It’s worth considering several of the advantages that panel surveys carry when considering this surveying method. You ought to then weigh them against the disadvantages to determine if this is the correct survey route for your market research needs.

  1. Easy Collection of the Sampling Pool: Whether you intend to use an online survey platform or a survey panel, panel surveys make it easy to use a qualified sampling pool. That is because there is no need to look for respondents on an individual basis; instead, you either opt for recruited participants, or the online survey platform you use prescreens respondents for qualification.

  2. Longitudinal Benefits: As it follows the longitudinal survey method, panel surveys allow you to truly access the psyche of your target market. This is because consumers and the general public can change their minds — some more regularly than others. By conducting this survey research, you can stay up to date with any and all changes in attitude, thoughts and behaviors your target market undergoes.
  3. Speed to Insights: Online survey tools allow you to quickly garner all the respondents that match your screening requirements and demographics selections. A survey panel entails that respondents have already opted into the survey. In any case, getting results will be quick.
  4. Optimized Design: Whether you use an online survey panel or organic random sampling via a survey platform, each allows you to create customized questionnaires. The degree of this will change from one survey platform to the next, but the convenience of optimizing your survey to your favor is still present.
  5. Affordability: Panel surveys are relatively affordable. With online survey panels, you should be wise about how you incentivize your panel — this can be done by paying the panelists small amounts per each survey they take, or a larger sum for a set amount of surveys. A decent online survey tool should include several payment plans, with at least one perfect for your budget. 

The Cons of Panel Surveys

While an invaluable form of primary research, panel surveys are not without setbacks. Here are a few of the disadvantages these surveys harbor. Some may appear minor, while others are more considerable.

    1. Panel Fatigue: Predominantly found in survey panels, this occurrence refers to the reduction of interest among the panelist(s) when they take part in too many survey waves. This breeds full-fledged boredom and exhaustion, leading to a decline in the quality of data. In this case, panelists may take part in flat-lining or other inaccurate answer tactics. There are 5 types of survey respondents like these to look out for. 

    2. Limited Internet Traffic: A problem principally found in online survey tools, as they are under the heel of the publisher sites and apps that deploy the surveys. There may not be enough qualifying respondents in one site or app, depending on who visits it during survey distribution.
    3. Survey Attrition: Piggybacking off of panel fatigue as the most severe case of it, survey attrition alludes to the dropping out of a panel. Panelists may experience a negative UX with the panel, thereby attriting at any wave of the study. These respondents are especially difficult to replace in survey panels, as they’ve already provided some crucial data, so there will be a void when it comes to conducting further surveys based on their responses. Some panelists do not drop out permanently, as they may return to the panel at some later time. With online surveys, this is relatively non-existent, as new responders are screened in each survey wave.
    4. Inclination towards Bias: Particular to survey panels, this occurs when panel respondents have taken too many surveys, thus becoming programmed to the way your surveys are set up. As such, they become less like genuine research subjects and more like trained survey-taking professionals. They may not put forth too much effort or thought into further survey waves because of this; rather they will clamber to get out of a survey as soon as possible.
    5. Respondent Identity Fraud: Especially common in online survey tools where you cannot validate the identity of your sampling pool, this can lead to respondent fraud. Respondents may lie about their age, employment and any other type of demographic identifier. Your data will suffer as a result. Survey panels may be immune to this if you choose your panel via face-to-face interviews, or if you know any member of the panel.

Panel Surveys: Uses and Applications

Panel surveys have various applications that you can put to use for your brand. Whether you’re looking to innovate an existing product, develop a new one, understand how your target market responds to current affairs, how they respond to certain communications or virtually anything else you need data for, panel surveys are useful ind=struments to leverage. 

Here are several specific uses and applications for these kinds of surveys.

  1. Detect common customer behaviors in relation to purchasing, clicking on an ad, or interacting with your brand in any other way (digital or physical).
  2. Analyze the costs of a product, service or subscription.
  3. Predict sales for particular campaigns and seasons.

  4. Understand how to use current affairs in brand messaging (including the knowledge of which subjects and rhetoric may be too sensitive for your target market).
  5. Monitor trends in how customers buy from brands.
  6. Find how recent and distant events have affected the attitude and opinions of your target market.
  7. Segmenting your target market. 

Marrying Survey Panels and Organic Sampling 

Closing off, it is crucial to reiterate that one of the key differentiators of panel surveys is their ability to incorporate two different types of survey respondent collection methods: survey panels and organic sampling (in online survey tools).

These fall into diametric opposition with one another, as the former involves recruiting willing survey respondents (the panel), while the latter uses organic sampling, in which respondents opt into a survey in real-time when they discover it in a website or app.

Although survey panels are the chief method to conduct panel surveys, due to the repeated nature of observation, both of these survey methods have the ability to sustain the longitudinal study method of panel surveys. 

Survey panels are the primary collection method of responses, as panel surveys and other longitudinal studies involve studying the same group of respondents. 

Survey panels do just that. However, survey tools that use organic sampling, can also study the same group based on their demographics and conditioned screening questions. The only difference is that the responders in organic sampling won’t be the exact same people, but rather those who fit the categories.

Either way these two methods can both be applied or even used hand in hand. We suggest using a robust online software tool that provides a wide range of features to optimize your survey research. 

Frequently asked questions

What is a panel survey?

A panel survey is a type of longitudinal study that follows the behavior of a predetermined group of people over a period of time. In a panel survey, data is gathered through a series of surveys conducted at set intervals.

What is a longitudinal study?

A longitudinal study is a form of research that makes observations and gathers data over a period of time, rather than at one single point in time.

What variables are examined in a panel survey?

Panel surveys tend to track feelings, attitudes, and opinions to understand how they change over time or in response to certain stimuli.

What are some of the benefits of using an online survey panel?

Online survey panels are cost-effective, can be distributed quickly, allow for easy data compilation to discover insights and offer an optimized design to improve response rate.

What is panel fatigue?

Panel fatigue is a phenomenon that occurs when a survey panelist participates in too many surveys and then becomes tired or bored with the survey process. This can lead to inaccuracies in survey data.

by lorraine

The 3 Major Types of Survey Research Methods

The 3 Major Types of Survey Research Methods

Within the ever-evolving and accelerating market research space, there is a litany of surveys making the rounds. Businesses are scrapping to get all the necessary consumer insights into their hands, and this is a fitting approach to satisfy any target market.

That’s because surveys allow you to gain an edge within your niche and outperform your competitors. While nothing is guaranteed, researchers and marketers have long been turning to surveys to observe the minds of their customers and potential customers.

Before perusing through the aforementioned litany of surveys, you ought to know about the different types of survey methods. That’s because there’s no “one size fits all” approach when it comes to survey research. 

Business needs vary, as do their industries, customers and campaigns. Let’s navigate the three most salient types of survey methods.

Survey Research — Beyond Distribution Type

In survey research, there are four types of distribution methods — but we won’t be covering those too much in depth. That is because they are widely known and seen. It’s virtually impossible for you or your business to not have heard of them in a limited capacity at the very least.

However, for the purpose of organizing the in-depth survey methods we discuss later into the deployment types, we’ll briefly mention them here. The four different types of survey deployment methods are:

  1. Paper surveys
    1. Written questionnaires
    2. Mail-in surveys
    3. Newspaper surveys
  2. Online surveys
    1. Online forms
    2. Proprietary surveys (on brand sites)
    3. Email surveys
    4. In-app surveys
    5. Third-party surveys
  3. Telephonic surveys
    1. Cold calling
    2. Anonymous respondents
  4. One-on-one interviews
    1. In-person and onsite interviews
    2. Less anonymity

All of these survey deployment types can serve both qualitative and quantitative research needs. The ones you choose to incorporate into your market research campaigns is ultimately up to the needs of your business. Some businesses prioritize ease, some prefer quick insights while others prefer cost-savings.

Now that you know survey distribution types, less delve further into specific survey methods.

Cross-Sectional Survey Studies

Cross-sectional surveys concentrate on a very specific point in time and exist as a quick overview of a small population sample. This method is ideal for situations wherein quick answers are needed to gain knowledge on standalone, or single situations. 

This survey method is based on three conditions: 

  1. the distribution of surveys to small samples 
  2. within large populations and 
  3. conducted over a small period of time.

The sample pool is drawn from specific variables, usually, only a few to narrow down a unique and usually small population. The findings are recorded within a short period of time and are studied and archived within that one specific point.

The variables are not manipulated as this type of research method is for observations only. This approach cannot measure causation between certain occurrences (ex. Inactivity and weight); rather, it measures the correlation between occurrences.

Longitudinal Surveys

The antithesis of cross-sectional surveys, longitudinal surveys study variables over a longer period of time. This can be anywhere between weeks and on the far end of the spectrum, decades. 

As such, they require more input in terms of several aspects, including participants, time and money. In this regard, a larger pool of participants is used and studied for much longer.

Similar to cross-sectional research, this method is also observational and studies the exact sample pool for the duration of the study.

Longitudinal surveys come in three main sorts:

  1. Trend surveys: 

    1. Study trends
    2. Observe how participants’ tendencies change over time
    3. Ask the same questions at different points in time
    4. Don’t necessarily study the exact same participants throughout, since the focus is on trends

  2. Panel surveys:

    1. Focus more on people than trends
    2. The same participants are studied throughout the duration of the study
    3. Tend to be more expensive and difficult (tracking & keeping up with the same people for years on end)

  3. Cohort surveys:

    1. Regularly study a group of participants that fall under a specific category
    2. Don’t require the same participants to take part every year
    3. Examples include those born within the same decade, workers of the same industry at the same time, other common life experiences

All three of these kinds of surveys help researchers study how people change and, as longitudinal research, they are also part of correlational research.  Longitudinal surveys help businesses and researchers scrutinize developments and changes.

They allow researchers to assess whether the changes are due to age, life factors or trends.

Retrospective Surveys

This survey method is yet another type based on frequency. It combines aspects of both cross-sectional and longitudinal survey methods. 

Retrospective surveys observe changes that occur over a longer period of time, much like longitudinal surveys. However, like cross-sectional surveys, they are facilitated just once. As such, responders discuss happenings from the past. These include feelings, attitudes, experiences and beliefs.

The findings are thereby longitudinal in nature, but performed in a cross-sectional fashion, ie, without requiring the long amounts of time to collect the data, like in traditionally longitudinal studies.

This scaling back on timing and monetary savings are the major advantages of this type of survey method. However, it does have its fair share of drawbacks, mainly those of memory distortion. For example, memories from the recent past may be vivid or clear enough to provide researchers with accuracy.

But memories of the more remote past, or even those of both the recent and distant past, when compared against one another, may lead to inaccurate answers.

Settling on the Correct Survey Method

Before you conduct any survey research, there are several questions you can stand to ask yourself or your own business. These should help you narrow down the proper survey method and distribution channel for your survey research. 

Here are some questions to consider which method is most suitable for you:

  • Do you need to gather long-term, continuous research or are you looking to gain insights on the current timeframe?
    • This will help you decide between choosing a cross-sectional or longitudinal survey study.
  • If you prefer a long-term study, are you willing to persist in obtaining responses from your sample pool, or do you want to pursue different respondents each time?
  • Would you prefer to survey the same group of respondents in the long term?
  • How often do you need survey responders to take part in your survey research campaign?
  • Are you looking to understand the development of people’s behaviors or trends within your industry?
  • If you don’t need to conduct a survey across a large span of time, do you need to question respondents about the past?
  • Do you need to study a specific category of participants, or can they fall within a more broad category?

As a business, you should cross-reference your responses to these questions with the information above. That way, you can make an educated decision about which survey method and (survey types) are best for your business. 

Frequently asked questions

What are the four methods of survey distribution?

The four survey deployment methods are paper surveys, online surveys, telephonic surveys, and surveys conducted via in-person interviews.

Why are cross-sectional surveys conducted?

Cross-sectional surveys are used to quickly get answers about a specific scenario at a certain point in time. They focus on a small sample size to provide a general overview of a specific scenario or situation.

What is a longitudinal survey?

A longitudinal survey studies a pool of participants over a set period of time. The period of time can range from weeks to many years. It is performed to understand how the respondents change or develop over time.

What are the three types of longitudinal surveys?

The three types of longitudinal surveys are trend surveys, panel surveys, and cohort surveys.

How is a retrospective survey different from a longitudinal survey?

Retrospective surveys are performed to observe changes that occur over time, but they are conducted only one time. The survey is performed to understand how the respondents feel or react to something that happened in the past.

by lorraine