Steffen Zitzmann

Prof. Dr. Steffen Zitzmann

Hector Research Institute of Education Sciences and Psychology, University of Tübingen, 72072 Tübingen, Germany

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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8 February 2024 in Educational Psychology Review
Verified
Journal Article
Open access
PDF file
DCDiego G. Campos
Diego G. Campos
TFTim Fütterer
Tim Fütterer
TGThomas Gfrörer
Thomas Gfrörer
RLRosa Lavelle-Hill
Rosa Lavelle-Hill
KMKou Murayama
Kou Murayama
RSRonny Scherer
Ronny Scherer
Systematic reviews and meta-analyses are crucial for advancing research, yet they are time-consuming and resource-demanding. Although machine learning and natural language processing algorithms may reduce this time and these resources, their performance has not been tested in education and educational psychology, and there is a lack of clear information on when researchers should stop the reviewing process. In this study, we conducted a retrospective screening simulation using 27 systematic reviews in education and educational psychology. We evaluated the sensitivity, specificity, and estimated time savings of several learning algorithms and heuristic stopping criteria. The results showed, on average, a 58% (SD = 19%) reduction in the screening workload of irrelevant records when using learning algorithms for abstract screening and an estimated time savings of 1.66 days (SD = 1.80). The learning algorithm random forests with sentence bidirectional encoder representations from transformers outperformed other algorithms. This finding emphasizes the importance of incorporating semantic and contextual information during feature extraction and modeling in the screening process. Furthermore, we found that 95% of all relevant abstracts within a given dataset can be retrieved using heuristic stopping rules. Specifically, an approach that stops the screening process after classifying 20% of records and consecutively classifying 5% of irrelevant papers yielded the most significant gains in terms of specificity (M = 42%, SD = 28%). However, the performance of the heuristic stopping criteria depended on the learning algorithm used and the length and proportion of relevant papers in an abstract collection. Our study provides empirical evidence on the performance of machine learning screening algorithms for abstract screening in systematic reviews in education and educational psychology.

29 May 2020 in Structural Equation Modeling: A Multidisciplinary Journal
Verified
Journal Article
Closed access
Steffen ZitzmannSteffen Zitzmann
Steffen Zitzmann
OLOliver Lüdtke
Oliver Lüdtke
Alexander RobitzschAlexander Robitzsch
Alexander Robitzsch
Martin HechtMartin Hecht
Martin Hecht
This journal recently published a systematic review of simulation studies on the performance of Bayesian approaches for estimating latent variable models in small samples. The authors of this review highlighted that Bayesian approaches can perform poorly (i.e., by exhibiting bias) when the prior distributions are not thoughtfully constructed on the basis of previous knowledge. In this comment, we question whether the bias is the most important criterion when the sample size is small. We argue that the variability is more important and should therefore not be ignored. Moreover, because one of the most important selling points of Bayesian approaches was not addressed in the article, we argue that although somewhat biased, Bayesian approaches allow for more accurate estimates (i.e., a smaller mean squared error) than Maximum Likelihood (ML) in small samples, and we show one such approach that is more accurate than ML.


11 January 2025 in Computers & Education
Verified
Journal Article
Open access
FMFitore Morina
Fitore Morina
TFTim Fütterer
Tim Fütterer
NHNicolas Hübner
Nicolas Hübner
Steffen ZitzmannSteffen Zitzmann
Steffen Zitzmann
CFChristian Fischer
Christian Fischer

25 January 2021 in Frontiers in Psychology
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Journal Article
Open access
PDF file
Steffen ZitzmannSteffen Zitzmann
Steffen Zitzmann
CHChristoph Helm
Christoph Helm
MHMartin Hecht
Martin Hecht
Bayesian approaches for estimating multilevel latent variable models can be beneficial in small samples. Prior distributions can be used to overcome small sample problems, for example, when priors that increase the accuracy of estimation are chosen. This article discusses two different but not mutually exclusive approaches for specifying priors. Both approaches aim at stabilizing estimators in such a way that the Mean Squared Error (MSE) of the estimator of the between-group slope will be small. In the first approach, the MSE is decreased by specifying a slightly informative prior for the group-level variance of the predictor variable, whereas in the second approach, the decrease is achieved directly by using a slightly informative prior for the slope. Mathematical and graphical inspections suggest that both approaches can be effective for reducing the MSE in small samples, thus rendering them attractive in these situations. The article also discusses how these approaches can be implemented in Mplus.

16 October 2024 in Research Synthesis Methods
Verified
Journal Article
Open access
LKLars König
Lars König
Steffen ZitzmannSteffen Zitzmann
Steffen Zitzmann
TFTim Fütterer
Tim Fütterer
DCDiego G. Campos
Diego G. Campos
RSRonny Scherer
Ronny Scherer
Martin HechtMartin Hecht
Martin Hecht
Several AI‐aided screening tools have emerged to tackle the ever‐expanding body of literature. These tools employ active learning, where algorithms sort abstracts based on human feedback. However, researchers using these tools face a crucial dilemma: When should they stop screening without knowing the proportion of relevant studies? Although numerous stopping rules have been proposed to guide users in this decision, they have yet to undergo comprehensive evaluation. In this study, we evaluated the performance of three stopping rules: the knee method, a data‐driven heuristic, and a prevalence estimation technique. We measured performance via sensitivity, specificity, and screening cost and explored the influence of the prevalence of relevant studies and the choice of the learning algorithm. We curated a dataset of abstract collections from meta‐analyses across five psychological research domains. Our findings revealed performance differences between stopping rules regarding all performance measures and variations in the performance of stopping rules across different prevalence ratios. Moreover, despite the relatively minor impact of the learning algorithm, we found that specific combinations of stopping rules and learning algorithms were most effective for certain prevalence ratios of relevant abstracts. Based on these results, we derived practical recommendations for users of AI‐aided screening tools. Furthermore, we discuss possible implications and offer suggestions for future research.