Daniël Lakens

Daniël Lakens
Eindhoven University of Technology | TUE · Research Group Human-Technology Interaction

Dr.

About

128
Publications
127,154
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
19,355
Citations
Citations since 2017
75 Research Items
17118 Citations
201720182019202020212022202301,0002,0003,000
201720182019202020212022202301,0002,0003,000
201720182019202020212022202301,0002,0003,000
201720182019202020212022202301,0002,0003,000

Publications

Publications (128)
Article
Full-text available
Known methodological issues such as publication bias, questionable research practices and studies with underpowered designs are known to decrease the replicability of study findings. The presence of such issues has been widely established across different research fields, especially in psychology. Their presence raised the first concerns that the r...
Article
This article details a correction to: Delacre, M., Lakens, D., & Leys, C. (2017). Why Psychologists Should by Default Use Welch’s 't'-test Instead of Student’s t-test. 'International Review of Social Psychology', 30(1), 92–101. DOI: https://doi.org/10.5334/irsp.82.
Article
Full-text available
In the January 2022 issue of Perspectives, Götz et al. argued that small effects are “the indispensable foundation for a cumulative psychological science.” They supported their argument by claiming that (a) psychology, like genetics, consists of complex phenomena explained by additive small effects; (b) psychological-research culture rewards large...
Preprint
Habits often conflict with goal-directed behaviors and this phenomenon has been convincingly demonstrated in instrumental learning experiments. Recent computational models explain habit-goal conflicts as the competitions between two learning systems, arbitrated by a central unit. In this paper, we show that habit-goal conflicts can be more parsimon...
Preprint
Objectives: Two longitudinal studies were conducted to examine how habits and goal-related constructs determine toothbrushing behavior from a dual-process perspective. We aimed to describe the variations of habit strength, intention, and attitude and to test their associations with actual behavior at both inter- and intraindividual levels. In addit...
Article
To help move researchers away from heuristically dismissing “small” effects as unimportant, recent articles have revisited arguments to defend why seemingly small effect sizes in psychological science matter. One argument is based on the idea that an observed effect size may increase in impact when generalized to a new context because of processes...
Article
Objectives: Two longitudinal studies were conducted to examine how habits and goal-related constructs determine toothbrushing behavior from a dual-process perspective. We aimed to describe the variations of habit strength, intention, and attitude and to test their associations with actual behavior at both inter- and intraindividual levels. In addi...
Article
Full-text available
Falsificationist and confirmationist approaches provide two well-established ways of evaluating generalizability. Yarkoni rejects both and invents a third approach we call neo-operationalism . His proposal cannot work for the hypothetical concepts psychologists use, because the universe of operationalizations is impossible to define, and hypothetic...
Article
Robust scientific knowledge is contingent upon replication of original findings. However, replicating researchers are constrained by resources, and will almost always have to choose one replication effort to focus on from a set of potential candidates. To select a candidate efficiently in these cases, we need methods for deciding which out of all c...
Article
Full-text available
The Action-sentence Compatibility Effect (ACE) is a well-known demonstration of the role of motor activity in the comprehension of language. Participants are asked to make sensibility judgments on sentences by producing movements toward the body or away from the body. The ACE is the finding that movements are faster when the direction of the moveme...
Article
Effect sizes are an important outcome of quantitative research, but few guidelines exist that explain how researchers can determine which effect sizes are meaningful. Psychologists often want to study effects that are large enough to make a difference to people's subjective experience. Thus, subjective experience is one way to gauge the meaningfuln...
Preprint
Researchers seeking to replicate original research often need to decide which of several relevant candidates to select for replication. Several strategies for study selection have been proposed, utilizing a variety of observed indicators as criteria for selection. However, few strategies clearly specify the goal of study selection and how that goal...
Preprint
Full-text available
Psychological researchers currently lack guidance for how to evaluate the practical relevance of observed effect sizes, i.e. whether a finding will have impact when translated to a different context of application. Although psychologists have recently highlighted theoretical justifications for why small effect sizes might be practically relevant, s...
Preprint
Researchers are generally required to report and interpret effect sizes and associated confidence intervals. When comparing two independent groups, the most commonly used estimator of effect size is Cohen’s ds where sample mean difference is divided by the pooled standard deviation. However, computing the pooled error term is not valid when both gr...
Preprint
Full-text available
Why ignoring indirect effects can harm science and scientists, and how changing the level of selection may help.
Article
Despite the growing popularity of digital health interventions, limitations of traditional behavior change theories and a lack of theory integration hinder theory-driven behavior change applications. In this paper, we aim to review theories relevant to lifestyle behavior change from the broader psychology literature and then integrate these theorie...
Article
Full-text available
Selectively publishing results that support the tested hypotheses (“positive” results) distorts the available evidence for scientific claims. For the past decade, psychological scientists have been increasingly concerned about the degree of such distortion in their literature. A new publication format has been developed to prevent selective reporti...
Preprint
Full-text available
Falsificationist and confirmationist approaches provide two well-established ways of evaluating generalizability. Yarkoni rejects both and invents a third approach we call neo-operationalism. His proposal cannot work for the hypothetical concepts psychologists use, because the universe of operationalizations is impossible to define, and hypothetica...
Article
Full-text available
Academic journals provide a key quality-control mechanism in science. Yet, information asymmetries and conflicts of interests incentivize scientists to deceive journals about the quality of their research. How can honesty be ensured, despite incentives for deception? Here, we address this question by applying the theory of honest signaling to the p...
Preprint
Full-text available
Researchers commonly make dichotomous claims based on continuous test statistics. Many have branded the practice as misuse of statistics, and criticize scientists for suffering from “dichotomania”. However, the role dichotomous claims play in science is not primarily a statistical one, but an epistemological and pragmatic one. The epistemological f...
Preprint
Full-text available
Psychological theories of habit posit that when a strong habit is formed through behavioral repetition, it can trigger behavior automatically in the same environment. Given the reciprocal relationship between habit and behavior, changing lifestyle behaviors (e.g., toothbrushing) is largely a task of breaking old habits and creating new and healthy...
Article
Full-text available
For almost half a century, Paul Meehl educated psychologists about how the mindless use of null-hypothesis significance tests made research on theories in the social sciences basically uninterpretable. In response to the replication crisis, reforms in psychology have focused on formalizing procedures for testing hypotheses. These reforms were neces...
Article
Full-text available
For almost half a century, Paul Meehl educated psychologists about how the mindless use of null-hypothesis significance tests made research on theories in the social sciences basically uninterpretable (Meehl, 1990). In response to the replication crisis, reforms in psychology have focused on formalising procedures for testing hypotheses. These refo...
Preprint
Robust scientific knowledge is contingent upon replication of original findings. However, researchers who conduct replication studies face a difficult problem; there are many more studies in need of replication than there are funds available for replicating. To select studies for replication efficiently, we need to understand which studies are the...
Article
Full-text available
To move beyond the limitations of null-hypothesis tests, statistical approaches have been developed where the observed data are compared against a range of values that are equivalent to the absence of a meaningful effect. Specifying a range of values around zero allows researchers to statistically reject the presence of effects large enough to matt...
Preprint
Full-text available
Academic journals provide a key quality-control mechanism in science. Yet, information asymmetries and conflicts of interests incentivize scientists to deceive journals about the quality of their research. How can honesty be ensured, despite incentives for deception? Here, we address this question by applying the theory of honest signaling to the p...
Article
Full-text available
Ongoing technological developments have made it easier than ever before for scientists to share their data, materials, and analysis code. Sharing data and analysis code makes it easier for other researchers to reuse or check published research. However, these benefits will emerge only if researchers can reproduce the analyses reported in published...
Article
Full-text available
Determining a lack of association between an outcome variable and a number of different explanatory variables is frequently necessary in order to disregard a proposed model (i.e., to confirm the lack of a meaningful association between an outcome and predictors). Despite this, the literature rarely offers information about, or technical recommendat...
Preprint
When studies with positive results that support the tested hypotheses have a higher probability of being published than studies with negative results, the literature will give a distorted view of the evidence for scientific claims. Psychological scientists have been concerned about the degree of distortion in their literature due to publication bia...
Article
Full-text available
Replication failures of past findings in several scientific disciplines, including psychology, medicine, and experimental economics, have created a “crisis of confidence” among scientists. Psychological science has been at the forefront of tackling these issues, with discussions about replication failures and scientific self-criticisms of questiona...
Preprint
UNSTRUCTURED Despite the growing popularity of digital health interventions, limitations of traditional behavior change theories and a lack of theory integration hinder theory-driven behavior change applications. In this paper, we aim to review theories relevant to lifestyle behavior change from the broader psychology literature and then integrate...
Preprint
Despite the growing popularity of digital health interventions, limitations of traditional behavior change theories and a lack of theory integration hinder theory-driven behavior change applications. In this article we review theories relevant to lifestyle behavior change from a broader psychology literature, and then integrate these theories to a...
Preprint
Full-text available
Replication failures of past findings in several scientific disciplines, including psychology, medicine, and experimental economics, have created a ‘crisis of confidence’ among scientists. Psychological science has been at the forefront of tackling these issues, with discussions about replication failures and scientific self-criticisms of questiona...
Article
Full-text available
Student’s 't'-test and classical 'F'-test ANOVA rely on the assumptions that two or more samples are independent, and that independent and identically distributed residuals are normal and have equal variances between groups. We focus on the assumptions of normality and equality of variances, and argue that these assumptions are often unrealistic in...
Preprint
Determining a lack of association between an outcome variable and a number of different explanatory variables is frequently necessary in order to disregard a proposed model (i.e., to confirm the lack of an association between an outcome and predictors). Despite this, the literature rarely offers information about, or technical recommendations conce...
Preprint
Ongoing technological developments have made it easier than ever before for scientists to share their data, materials, and analysis code. Sharing data and analysis code makes it easier for other researchers to re-use or check published research. These benefits will only emerge if researchers can reproduce the analysis reported in published articles...
Article
Full-text available
Researchers often lack knowledge about how to deal with outliers when analyzing their data. Even more frequently, researchers do not pre-specify how they plan to manage outliers. In this paper we aim to improve research practices by outlining what you need to know about outliers. We start by providing a functional definition of outliers. We then la...
Article
Full-text available
When data analysts operate within different statistical frameworks (e.g., frequentist versus Bayesian, emphasis on estimation versus emphasis on testing), how does this impact the qualitative conclusions that are drawn for real data? To study this question empirically we selected from the literature two simple scenarios—involving a comparison of tw...
Preprint
Full-text available
Effect sizes are an important outcome of quantitative research because they allow researchers to communicate the practical significance of the findings. However, there are few guides for psychological researchers that explain how they can quantify which effect sizes are practically meaningful, and which are not. Being able to specify the smallest e...
Preprint
Full-text available
When data analysts operate within different statistical frameworks (e.g., frequentist versus Bayesian, emphasis on estimation versus emphasis on testing), how does this impact the qualitative conclusions that are drawn for real data? To study this question empirically we selected from the literature two simple scenarios --involving a comparison of...
Article
Full-text available
We conducted preregistered replications of 28 classic and contemporary published findings, with protocols that were peer reviewed in advance, to examine variation in effect magnitudes across samples and settings. Each protocol was administered to approximately half of 125 samples that comprised 15,305 participants from 36 countries and territories....
Preprint
Full-text available
We conducted preregistered replications of 28 classic and contemporary published findings with protocols that were peer reviewed in advance to examine variation in effect magnitudes across sample and setting. Each protocol was administered to approximately half of 125 samples and 15,305 total participants from 36 countries and territories. Using co...
Article
We conducted preregistered replications of 28 classic and contemporary published findings, with protocols that were peer reviewed in advance, to examine variation in effect magnitudes across samples and settings. Each protocol was administered to approximately half of 125 samples that comprised 15,305 participants from 36 countries and territories....
Article
Full-text available
Being able to interpret ‘null effects?is important for cumulative knowledge generation in science. To draw informative conclusions from null-effects, researchers need to move beyond the incorrect interpretation of a non-significant result in a null-hypothesis significance test as evidence of the absence of an effect. We explain how to statistically...
Article
The debate about whether replication studies should become mainstream is essentially driven by disagreements about their costs and benefits and the best ways to allocate limited resources. Determining when replications are worthwhile requires quantifying their expected utility. We argue that a formalized framework for such evaluations can be useful...
Article
Full-text available
Although context effects have repeatedly been demonstrated, it remains difficult to predict how context features influence the associative meaning of concepts. In a recent series of Experiments (see Part 1, Schietecat, Lakens, IJsselsteijn, & de Kort, 2018), we proposed and tested the dimension-specificity hypothesis for understanding and predictin...
Article
Researchers often conclude an effect is absent when a null-hypothesis significance test yields a non-significant p-value. However, it is neither logically nor statistically correct to conclude an effect is absent when a hypothesis test is not significant. We present two methods to evaluate the presence or absence of effects: Equivalence testing (ba...
Article
Full-text available
Psychologists must be able to test both for the presence of an effect and for the absence of an effect. In addition to testing against zero, researchers can use the two one-sided tests (TOST) procedure to test for equivalence and reject the presence of a smallest effect size of interest (SESOI). The TOST procedure can be used to determine if an obs...
Article
Full-text available
Psychologists must be able to test both for the presence of an effect and for the absence of an effect. In addition to testing against zero, researchers can use the two one-sided tests (TOST) procedure to test for equivalence and reject the presence of a smallest effect size of interest (SESOI). The TOST procedure can be used to determine if an obs...
Article
Full-text available
Psychologists must be able to test both for the presence of an effect and for the absence of an effect. In addition to testing against zero, researchers can use the two one-sided tests (TOST) procedure to test for equivalence and reject the presence of a smallest effect size of interest (SESOI). The TOST procedure can be used to determine if an obs...
Chapter
We discuss a decision-making perspective on coaching behavior change and report a field experiment following the perspective in which we promoted physical exercises at work using an e-coaching app. More specifically, we investigated what are the important attributes that influence the attractiveness of exercise options, and whether showing an extre...
Preprint
To facilitate a better understanding of the role of self-control capacity in self-control processes, we examined its variation at intraindividual and interindividual levels, and positioned it in a nomological network with core affect. In two experience sampling studies, 286 university students reported their self-control capacity and core affect fo...
Article
To facilitate a better understanding of the role of self-control capacity in self-control processes, we examined its variation at intraindividual and interindividual levels, and positioned it in a nomological network with core affect. In two experience sampling studies, 286 university students reported their self-control capacity and core affect fo...
Article
Full-text available
In response to recommendations to redefine statistical significance to P ≤ 0.005, we propose that researchers should transparently report and justify all choices they make when designing a study, including the alpha level.
Article
Full-text available
In response to recommendations to redefine statistical significance to P ≤ 0.005, we propose that researchers should transparently report and justify all choices they make when designing a study, including the alpha level.
Preprint
Researchers often conclude an effect is absent when a null-hypothesis significance test yields a non-significant p-value. However, it is not logically nor statistically correct to conclude an effect is absent when a hypothesis test is not significant. We present two methods to evaluate the presence or absence of effects: Equivalence testing (based...
Preprint
When comparing independent groups, researchers in psychology commonly use Analysis of Variance (ANOVA), which assumes data is normally distributed, and variances are equal across conditions. When these assumptions are not met, the classical ANOVA (F-test) can be severely biased, which leads to invalid statistical inferences. However, despite their...
Preprint
Full-text available
In a summary of recent discussions about the role of direct replications in psychological science, Zwaan, Etz, Lucas, and Donnellan (2017; henceforth ZELD) argue that replications should be more mainstream, and discuss six common objections to direct replication studies. We believe that the debate about the importance of replication research is ess...
Article
When designing a study, the planned sample size is often based on power analyses. One way to choose an effect size for power analyses is by relying on pilot data. A-priori power analyses are only accurate when the effect size estimate is accurate. In this paper we highlight two sources of bias when performing a-priori power analyses for between-sub...
Preprint
Psychologists must be able to test both for the presence of an effect and for the absence of an effect. In addition to testing against zero, researchers can use the Two One-Sided Tests (TOST) procedure to test for equivalence and reject the presence of a smallest effect size of interest (SESOI). TOST can be used to determine if an observed effect i...
Article
Full-text available
Psychology journals rarely publish nonsignificant results. At the same time, it is often very unlikely (or “too good to be true”) that a set of studies yields exclusively significant results. Here, we use likelihood ratios to explain when sets of studies that contain a mix of significant and nonsignificant results are likely to be true or “too true...
Preprint
Full-text available
In response to recommendations to redefine statistical significance to p ≤ .005, we propose that researchers should transparently report and justify all choices they make when designing a study, including the alpha level.
Preprint
When designing a study, the planned sample size is often based on power analyses. One way to choose an effect size for power analyses is by relying on pilot data. A-priori power analyses are only accurate when the effect size estimate is accurate. In this paper we highlight two sources of bias when performing a-priori power analyses for between-sub...
Article
Parkinson's disease (PD) is often characterized by asymmetrical symptoms, which are more prominent on the side of the body contralateral to the most extensively affected brain hemisphere. Therefore, lateralized PD presents an opportunity to examine the effects of asymmetric subcortical dopamine deficiencies on cognitive functioning. As it has been...
Article
Full-text available
Scientists should be able to provide support for the absence of a meaningful effect. Currently, researchers often incorrectly conclude an effect is absent based a nonsignificant result. A widely recommended approach within a frequentist framework is to test for equivalence. In equivalence tests, such as the two one-sided tests (TOST) procedure disc...
Article
Full-text available
When comparing two independent groups, psychology researchers commonly use Student’s 't'-tests. Assumptions of normality and homogeneity of variance underlie this test. More often than not, when these conditions are not met, Student’s 't'-test can be severely biased and lead to invalid statistical inferences. Moreover, we argue that the assumption...
Preprint
Full-text available
Meta-analyses are an important tool to evaluate the literature. It is essential that meta-analyses can easily be reproduced to allow researchers to evaluate the impact of subjective choices on meta-analytic effect sizes, but also to update meta-analyses as new data comes in, or as novel statistical techniques (for example to correct for publication...
Preprint
When comparing two independent groups, researchers in Psychology commonly use Student’s t-test. Assumptions of normality and of homogeneity of variance underlie this test. More often than not, when these conditions are not met, Student’s t-test can be severely biased, and leads to invalid statistical inferences. Moreover, we argue that the assumpti...
Preprint
When comparing two independent groups, researchers in Psychology commonly use Student’s t-test. Assumptions of normality and of homogeneity of variance underlie this test. More often than not, when these conditions are not met, Student’s t-test can be severely biased, and leads to invalid statistical inferences. Moreover, we argue that the assumpti...
Preprint
Psychology journals rarely publish non-significant results. At the same time, it is often very unlikely (or ‘too good to be true’) that a set of studies yields exclusively significant results. Here, we use likelihood ratios to explain when sets of studies that contain a mix of significant and non-significant results are likely to be true, or ‘too t...
Article
Full-text available
Processing action-language affects the planning and execution of motor acts, which suggests that the motor system might be involved in action-language understanding. However, this claim is hotly debated. For the first time, we compared the processing of action-verbs in children with Developmental Coordination Disorder (DCD), a disease that specific...
Conference Paper
Full-text available
Mobile computing systems hold the promise of becoming a cost-effective solution for supporting behavior change towards more healthy lifestyles. We present here an approach where the system implements a formal model of habit formation based on psychology theories, anticipates the behaviors and cognitive states of the users, and picks interventions b...
Article
Full-text available
Background Meta-analyses play an important role in cumulative science by combining information across multiple studies and attempting to provide effect size estimates corrected for publication bias. Research on the reproducibility of meta-analyses reveals that errors are common, and the percentage of effect size calculations that cannot be reproduc...
Article
Full-text available
Openness is one of the central values of science. Open scientific practices such as sharing data, materials, and analysis scripts alongside published articles have many benefits, including easier replication and extension studies, increased availability of data for theory-building and meta-analysis, and increased possibility of review and collabora...
Article
Full-text available
Empirically analyzing empirical evidence One of the central goals in any scientific endeavor is to understand causality. Experiments that seek to demonstrate a cause/effect relation most often manipulate the postulated causal factor. Aarts et al. describe the replication of 100 experiments reported in papers published in 2008 in three high-ranking...
Article
Full-text available
In recent years, researchers have attempted to provide an indication of the prevalence of inflated Type 1 error rates by analyzing the distribution of p-values in the published literature. De Winter & Dodou (2015) analyzed the distribution (and its change over time) of a large number of p-values automatically extracted from abstracts in the scienti...