How to Use Incentives in an Experience Sampling Study

In our previous post, we discussed the value of balancing participant motivation and burden through sampling protocol. In this post, we will discuss the ways in which incentives can be used to increase participant motivation. Whether intrinsic (altruistic or prosocial) or extrinsic (financial or achievement-based), the inclusion of a thoughtful incentive structure to your study can help to raise participant motivation, leading to stronger data and higher retention rates overall.

Intrinsic Motivation in Experience Sampling

Altruism can refer to the desire to protect or promote the well-being of others outside of personal gain. In the context of experience sampling, altruistic motivation refers to a participant’s belief that the research in which they are taking part will benefit the well-being of other people. This is closely related to prosocial motivation, which is the desire to benefit other people, but it differs in that prosocial motivation allows for self-interest as well. For example, a candidate with anxiety may believe that they are helping other people with anxiety by participating in a study on an anti-anxiety medication but may also recognize that they can personally benefit from participation. From both goals, they will draw powerful intrinsic motivation. See this study by A. M. Grant for further reading. Although Grant’s research is primarily over the application of prosocial motivation in the workplace, researchers will find it useful for motivating their experience sampling study participants.

By highlighting the societal benefits of a study, researchers can increase their participants’ intrinsic and prosocial motivation. Showing participants how the research will contribute to scientific progress, improve society, benefit a particular group, or further a particular cause may also increase this intrinsic motivation.

Some methods of encouraging intrinsic motivation include:

  • Communicating the impact of your research: Tell your participants how participation can have a broader social or societal impact.

  • Personal touches: Send personalized messages, personal feedback, and institute regular check-ins, especially for long-running studies.

  • Gratitude: Send regular expressions of your gratitude to your participants via email, thank you notes, SMS, or even phone calls.

  • Appealing to extrinsic motivation and social norms: Emphasize the ways in which high engagement leads to a successful study and a high impact on the broader world. Share success stories and/or data as it becomes available to encourage them. For example, “currently our study response rate is over 90%, help us keep it that way!”

  • Strong and streamlined two-way communication channels: Foster open communication channels where participants can voice their concerns, ask questions, and provide feedback.

Extrinsic Monetary Incentives in Experience Sampling

While monetary or financial incentives are commonly recommended for researchers conducting experience sampling studies, the literature is mixed on the role and success rate of these financial incentives. One systematic review of experience sampling studies in education did not find a statistically significant relationship between monetary incentives and compliance rates (Mölsä et al., 2022). However, other studies have found that financial incentives can increase extrinsic motivation and increase engagement, particularly among younger participants (Cameron & Pierce, 2002; Heron et al., 2017 ; Wen et al., 2017). Taken together, research suggests that participants’ engagement depends on a blend of economic, assistive, reciprocative, and altruistic motives (van Berkel et al., 2017).

Monetary incentives come with a series of decisions which researchers must consider:

  • What type of financial incentive will be used? Gift cards, cash, or even SIM cards may be appropriate for adult or adolescent participants, where non-monetary extrinsic rewards like toys, stickers, or notepads may be appropriate for smaller children (read more here: Heron et al., 2017).

  • What is the criterion for payment? What does a participant need to achieve to become eligible for payment? How will you track eligibility?

  • How frequently will participants be paid? Will participants receive payment at the end of the study? At the end of each week? Bi-weekly?

  • By what means will participants be paid? What system will be used to deliver payment? Will you need additional personal information, such as a completed W-9 form, in order to issue payment legally? Read more about tax considerations here, both for US and non-US residents.

With financial rewards, it’s also important to consider the different types of payment structures available:

  • Fixed payment: Participants will receive a set amount, regardless of their response rate, as long as the study is completed.

  • Fixed payment (with a threshold): Participants will receive a set amount, but only if they achieve a particular response rate.

  • Per-Response: Participants are paid a specified amount per response submitted.

  • Completion Bonuses: Often used in conjunction with another incentive structure, participants receive a bonus for surpassing a response rate threshold or study milestone.

  • Progressive Rewards: Participants receive increasing compensation based on longer participation.

  • Tiered Rewards: Participants falling into different response rate ranges are eligible for different levels of compensation.

The amount of money offered is also a unique consideration for researchers. An older study from 1991 found that particularly high rewards could also prompt participants to pay others to fill out questionnaires for them, damaging the quality of data received (cited in van Berkel et al., 2017). Ethically speaking, researchers must ensure that incentives are incentivizing, but not coercive. Rewards should not be so large that a participant would choose to join a study against their better judgement, especially when there is risk to their physical or mental health. Although altruism alone may not be enough to motivate a participant to finish a study, especially a longer-running study, financial incentives must be used sparingly. Researchers will need to find the right balance for their study based on the amount of burden associated (time and effort participants must expend) and the running time of their study.

Extrinsic Achievement-Based Incentives in Experience Sampling

Achievement-based incentives are rewards or recognition given to individuals for reaching specific milestones or accomplishing predetermined goals which are designed to motivate and reinforce the desired study behaviors or outcomes. Some common examples of achievement-based incentives include gamified user interfaces and in-app displays of study progress. While achievement-based incentives are possible with many types of studies, they are most common with mobile-based or “bring your own device” studies. The impact of gamification on experience sampling data collection is an area of ongoing research, but there is evidence from recent studies that gamification improves data collection and quality (read more here: van Berkel et al., 2017Hamari et al., 2014).

Some advantages of achievement-based incentives include:

  • Participant enjoyment: They make responding to prompts more enjoyable and may increase participant motivation.

  • Clarity: They can clarify and remind participants of key objectives and milestones, particularly in studies lasting longer than a few days.

  • Feedback: These incentives can also provide immediate feedback on progress toward established milestones.

Some key factors to consider when designing or selecting achievement-based incentives are:

  • User-Friendliness: How intuitive or easy is it to navigate the interface?

  • Accessibility: Is it accessible to all age and ability groups in your study population? Are the controls simple to learn? Are there accessibility options, such as larger typeface, bigger buttons, or assistive reading available to users who need them?

  • Privacy: Does the interface protect users’ privacy? Will the participants have outward-facing data, such as a profile picture or username, which is visible to other participants?

When conducting an experience sampling study, researchers have a lot to consider. One of the key considerations is finding the right balance between participant burden and participant motivation, as we discussed in our earlier post. By using a blend of intrinsic and extrinsic motivators, researchers can enhance participant motivation, helping their study to gain stronger data and higher retention rates.


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