Have you ever noticed how the first performer in a competition seems to set the tone for the rest of the competition, while everything seems to blend until the final performance? That is how the serial position effect works.

The serial position effect describes how people tend to remember items at the beginning or end of a list more than those in the middle. This phenomenon demonstrates that the order in which items are arranged has a strong relationship with how people who see them can recall them.

Let’s find out how researchers can leverage the serial position effect to arrange questions in a way that elicits accurate responses from survey participants.

What Is the Serial Position Effect?

The serial position effect describes how people remember items in a list. Hermann Ebbinghaus, a German psychologist, was the first to notice the concept in the late 1800s.

It describes how people remember items at the beginning and end of a list but don’t recall or recall inaccurately those in the middle.

The tendency for people to remember items at the beginning of a list is known as the primary effect. This is based on the fact that the items at the beginning mark your first encounter with the list, so it tends to shape your perspective of the list, which it easy to remember them.

While it’s known as the recency effect for items at the end of the list, it’s the most recent item you’ve seen so your memory is still fresh and it seals your impression of the list.

Origins of the Serial Position Effect

Hermann Ebbinghaus, a German psychologist, coined the term “serial position effect” in the late 1800s. He conducted an experiment in which he showed participants a list of random made-up syllables created by combining letters randomly and assessed their ability to recall the list’s content at different time intervals.

At the end of the experiment, he discovered that people recalled items at the beginning and end of the list more than those in the middle. Following this experiment, the concept has been examined in different contexts using various simulations such as images, sounds, verbal lists, and written lists.

What Causes the Serial Position Effect?

Primary and Recency Effect

According to the primary effect theory, people tend to remember things at the top of the list because they pay a lot of attention to new information before moving down the list.

The recency effect states that people typically recall items at the bottom of the list because they were the last seen by the person and are thus still fresh in the person’s memory.

Long and Short-term Memory

Another theory is how long-term and short-term memory work. According to this theory, items at the top of the list are more likely to be transferred from short-term memory to long-term memory.

One major reason for this is that people pay attention to items at the top of the list; it’s the very first information they see, so they’ll take their time processing the information to properly understand it. As a result, recalling it would be relatively simple because it is a memory that people will carry with them for a long time.

The items at the bottom of the list, on the other hand, are in working memory (short-term memory) and can be retrieved quickly. The reason for this is that, unless there is a similar list or something that requires intense concentration, people remember the last thing they saw quite well until something else draws their attention away.

There’s also evidence to support this long and short-term memory theory. Multiple studies have found that when people aren’t given enough time to transfer information to their long-term memory, they recall items at the top of the list inaccurately, but recall those at the end regardless.

Other Factors that Cause the Serial Position Effect

Other factors that influence how well people recall items on the list include list length, its content, and how different people recall things.

The serial position effect, for example, is stronger for longer lists and more pronounced in verbal content than visual material. Most people remember visual material based on what they are drawn to, regardless of where it appears on the list.

Also, people process information differently depending on their attention span, memory abilities, and even the type of information they are exposed to. If people are shown a list of items that they are very familiar with or have a strong emotional attachment to, they may recall it regardless of its position on the list.

Implications of the Serial Position Effect on Surveys

Inaccurate Survey Results

The serial position effect has a significant impact on research surveys because it influences how people recall and report data.

According to the phenomenon, people are more likely to remember the items at the top of the list and those at the bottom than those in the middle. This implies that respondents may not remember accurately the items in the middle, which could lead to loads of inaccurate answers in the survey results.

For example, if a product design survey asks respondents to choose the designs they prefer, respondents may overlook the product designs in the middle and only compare the designs at the top and bottom of the list. So, the survey results may show a false representation of the best design.

Bias in Responses

The serial position effect can be a significant source of bias in survey responses, particularly if the questions are not randomized.

For example,  if the questions at the start of an NPS survey are favorable because the brand or product excels in that area; participants tend to give the brand or product a high satisfaction score primarily because of the first impression (primary effect). The same principle applies if the survey begins with unfavorable responses.

However, you can reduce the impact of the serial position effect by presenting the items in a randomized order, allowing participants to see different options. So, their first or last impressions don’t stick and the survey results are a true representation of how customers feel about your brand or products.

Read – Research Bias: Definition, Types + Examples

Incomplete or Missing Responses

The serial position effect may result in missing data in surveys, especially if the survey is very long. 

If respondents have difficulty recalling items in the middle of the list, they may skip them or provide inaccurate responses at random. This results in missing survey data which reduces the validity and reliability of the survey results.

Read: How To Handle Missing Data in Surveys & Questionnaires

Examples of Serial Position Effect

• Spelling Test

When educators give students a list of new words to memorize before a spelling bee, students are more likely to remember the words at the top and bottom of the list than those in the middle.

• Crime Witness Statement

Also, when witnesses are asked to write a detailed statement about a crime, the statement is more likely to focus on how the crime began and ended than on what happened during the event.

• Recalling Names of People at an Event

People are more likely to remember the names of people they met at the start and end of an event than those they met in the middle. The first people we meet at an event make an impression on us, and the last is our takeaway memory from the event.

• Image Recognition

Participants are more likely to remember images at the beginning and end of a list than those in the middle if they are given a list of images to study for a set time and then asked to identify what they recall.

• Sound Recognition

The serial position effect also happens with sound. When we listen to people talk in a presentation, the key takeaways are usually the introduction and the conclusion.

This is why, at the end of most presentations, there is a list of key takeaways to recap everything said so that the audience recalls it. It allows the audience to make insightful comments at the end of the presentation.

Serial Position Effect Tips for Your Survey

Here are a few tips for minimizing the influence of the serial position effect in your survey:

• Randomize the Order of the Items on the List

You can reduce the impact of the serial position effect on the responses by presenting the items on the list in a randomized order. This ensures that the responses accurately reflect the underlying characteristics of the sample being studied and are not influenced by the order in which the items were presented.

• Create Separate Scaling for each Item

Instead of presenting a list of items and asking respondents to rate them all at once, consider using separate rating scales for each item. This can help to ensure that all items receive equal attention and consideration from respondents, rather than being influenced by the serial position effect.

• Keep the List of Items Short

Try to keep the list of items as short as possible. The serial position effect is generally stronger for longer lists, so keeping the list short can help reduce the effect’s influence on the responses.

• Use Simple and Clear Language

When presenting the items on the list, use clear and simple language. This ensures that respondents fully understand the question and provide accurate responses.

• Add Illustrations

Consider using visual aids to help illustrate the items on the list if possible. This makes the items more memorable and lessens the impact of the serial position effect on the respondents.

How to Avoid the Serial Position Effect When You Want

Researchers can take multiple steps to reduce the effects of the serial position effect in research surveys. You can start by randomizing the order of the items on the list so that each respondent sees the items in a different order.

You can also use other techniques, such as asking respondents to rate each item on the list separately rather than presenting the list as a whole.

When analyzing data as a researcher, you can use statistical methods as modifications for the serial position effect. This ensures that the survey responses are unbiased.

Conclusion

The serial position effect is a psychological phenomenon that describes how people recall items from a list. It has significant implications for research surveys because it influences how respondents recall and report information.

Understanding the serial position effect and taking steps to reduce its influence ensure that survey responses are valid and reliable.