Zum Hauptinhalt springen

Learning deficit among students during COVID-19 pandemic


  • students lose 35 percent of normal learning progress during COVID-19 pandemic

  • especially children with low socioeconomic status and from low-income countries are affected

  • researchers see need to provide additional services to compensate the learning deficit

During the COVID-19 pandemic, students lost more than one-third of their normal learning gains per school year. That's according to a meta-analysis published January 30, 2023, in the journal „Nature Human Behavior“ (see primary reference). The large-scale analysis includes 42 studies from 15 countries, including primarily studies from the United Kingdom and the United States, but also four studies from Germany. In addition to learning deficits in various school subjects, sociodemographic status and average income in the country were also recorded.

The analysis showed that learning progress slowed considerably during the COVID-19 pandemic – students lost a total of 35 percent of the learning progress of a normal school year. The learning deficit was most severe among children of low socioeconomic status, but no significant differences were evident between grade levels. The deficit was greater in math than in reading, which the authors explained by the fact that parents and children are more likely to read together from home than to work on math tasks. In addition, some of the studies showed that the learning deficit did not narrow over the course of the pandemic, but persisted between May 2020 and May 2022.

In middle-income countries such as Brazil and Mexico, the learning deficit was greater than in high-income countries such as the United States and the United Kingdom. The authors criticize that their meta-analysis does not include studies from low-income countries and therefore lacks a comparison with this group.

Independent researchers approached by the SMC for this study speak of the immense relevance of the learning deficit for the education system, as it has made the required standards of the curricula difficult to achieve. The shortage of teachers makes it difficult to catch up with learning, especially for students from low-income households. Even if it is difficult, however, there are ways to make up the learning deficit – for example, through summer schools or digital support.



  • Prof. Dr. Klaus Zierer, Professor of School Education, University of Augsburg

  • Prof. Dr. Benjamin Fauth, Head of the Department of Empirical Educational Research, Institute for Educational Analysis Baden-Wurttemberg (IBBW), and Adjunct Professor at the Hector Research Institute of Education Sciences and Psychology, University of Tübingen


Prof. Dr. Klaus Zierer

Professor of School Education, University of Augsburg

„Ever since 'Visible Learning', John Hattie's milestone in empirical educational research, meta-analyses have been an integral part of educational discourse. They help to calculate a general effectiveness of pedagogical measures from the multitude of research results that are collected worldwide and at the same time make country- or culture-specific characteristics visible. The procedure of a meta-analysis is defined by standards (e.g. 'Prisma') and is adhered to in the present study. In this respect, it can be concluded that the article meets the state of the art in the field of meta-analyses. Incidentally, the results also correspond one-to-one with my own meta-analysis in this field [1]. The more data does not provide a fundamentally new result, but confirms previous meta-analyses on a larger data base."

„The relevance of the learning deficit found is immense because it has a direct impact on teaching. The lower the learning performance, the more difficult it becomes for learners to achieve the standards required by the curricula. As a result, a 'Generation COVID can be expected to form, which has suffered particularly badly from the pandemic. This particularly affects the youngest in the system from economically weak countries with educationally deprived backgrounds. This once again highlights the educational inequity in the country and also worldwide. What was not highlighted in the meta-analysis, but for which there is also relevant research, is that the pandemic also had a negative impact on psychosocial development and physical condition. In 'A Year to Forget' I evaluated and analysed this aspect [2]."

„Everything should be done to make up for the learning deficits. Unfortunately, many countries missed the first opportunities - keyword 'summer schools' - or implemented them absolutely unreflectively. As a result, even more time has been lost. From research we know (unfortunately) that learning deficits accumulate quickly and therefore become bigger and bigger. The earlier it is possible to counteract this, the better it is. The problem is certainly that in view of a (worldwide) shortage of teachers, there is above all a lack of personnel. In addition, the concepts have not been worked out and everyone is looking to digitalisation, which, however, has not proven to be a saviour in the pandemic, but rather a driver of educational gaps (especially in leisure time due to increasing and unreflective consumption). Rather, digitalisation is a driver of educational injustice because digital media are used differently depending on the level of education. Thus, the challenge for the next two or three years remains to offer sensible concepts here."

„From an empirical point of view, summer schools are certainly an interesting option because they have been able to show in the past that they have a positive effect on all children and young people - but especially on learners from educationally deprived milieus. Here, we could benefit from research and existing concepts worldwide. Certainly, digitalisation also offers potential if it is implemented wisely. What has happened in many cases - pushing tablets into the hands of learners and hoping that they will have a positive effect - must be seen as a failure and it is high time to use the possibilities of digitalisation and at the same time avoid the dangers. Thus, digital media can be helpful for individual support, because with them learning paths can be implemented that always place learners in the area of challenging learning tasks and at the same time relieve teachers so that they can relate to the learners even more."

Prof. Dr. Benjamin Fauth

Head of the Department of Empirical Educational Research, Institute for Educational Analysis Baden-Wurttemberg (IBBW), and Adjunct Professor at the Hector Research Institute of Education Sciences and Psychology, University of Tübingen

„The study is methodologically very well designed. In meta-analyses of this kind (i.e., studies in which the results of many individual studies are considered together), it is important that the quality of the individual studies included in the evaluation is checked very carefully. This has obviously been done very meticulously here. The paper is probably the most comprehensive study to date of post-corona pandemic learning deficits. When interpreting the findings, it must of course be taken into account that studies from different countries were included here, some of whose results cannot be transferred to the German education systems. For example, the learning gaps in poorer countries are once again significantly greater than in a rather rich country like Germany. But overall, we also see learning gaps in this country, and we especially see their uneven distribution: students who already had a harder time before the pandemic are much more affected."

„The learning deficits observed in the meta-analysis are significant. Those we found in studies from Germany, for example in Hamburg and in Baden-Wurttemberg, are somewhat smaller, but tend to point in the same direction. Pandemic-related learning deficits certainly also play a role in the findings recently presented in the IQB Education Trends. Not only are the backlogs themselves unevenly distributed socially, but their consequences are also likely to vary widely: many students with the appropriate social background will easily make up for it. However, the consequences will be more severe, especially for lower achievers and for students from less educated homes. In addition, the study focuses on cognitive learning deficits, i.e. on the question of what students have learned - or not learned - in German and math, for example. If you ask teachers, it becomes clear that in addition to the actual learning deficits, there is another problem in the foreground, namely the whole psychosocial area. My impression is that schools currently have a lot of work to do in this area to reestablish certain learning routines and to get the whole social interaction back on track."

„The federal government has already made extensive funds available for a so-called catch-up program. But it is also clear that these measures alone will not be enough in the end. Additional support measures are important, of course, but we will only be able to reduce social inequalities if the great heterogeneity (i.e., difference/diversity) of the students is also taken more into account in the normal classroom. In the end, it will only work through targeted support in regular classes as well. If additional resources are made available now, attention must be paid to how these resources are distributed. We can clearly see from the data that certain students have suffered particularly from the pandemic - precisely those who were already having a hard time. The task now must be to provide targeted support for precisely these students - including in regular classes. In a large state like Baden-Wurttemberg, about half of the students now have a so-called migration background. Given this number, we cannot, for example, pretend that it is the normal case that all children in our elementary schools speak perfect German. Such things must be systematically taken into account in the classroom. We can't afford as a democratic society - or, for that matter, as an economy - to have a portion of our students take so little away from school."

„It is important to see that many of the problems that are now becoming visible in schools would have to be addressed even without a pandemic. It is good that the connection between the social background of the students has now become more present again as an issue in the education policy debate. Fortunately, there is also a great deal of agreement that these problems must now be addressed. It is also interesting to see that schools have come through the pandemic with varying degrees of success. For example, classes where the relationship between students and their teachers was positive even before the pandemic had a much easier time during the school closures. We saw the importance of good feedback to students that promotes learning at the latest when schools were closed from one day to the next and teachers had to consider the ways in which they could still reach their students at all.“

„There are schools that had already established a system before the pandemic that allows them to keep a close eye on learning progress - so that they can provide direct and targeted support in the event of learning problems. During the school closures, it then became clear how important this is. During the pandemic, there has been huge progress in many schools - not only in digitization, but also in how we can use digital tools pedagogically so that they support learning. I hope these things don't disappear back into closets and drawers now. In perspective, these are also the approaches that will help us deal with the consequences of the pandemic in schools."

Conflict of interest

Prof. Dr. Benjamin Fauth: „I collaborated on two studies that were included in the meta-analysis (Schult et al.), but otherwise have no conflicts of interest.“

Others: None received.

Primary reference

Betthäuser BA et al. (2023): A systematic review and meta-analysis of the evidence on learning during the COVID-19 pandemic. Nature Human Behaviour. DOI: 10.1038/s41562-022-01506-4.

Further research sources

Science Media Center España (2023): Reactions: pandemic caused educational delays equivalent to a third of the academic year.

References, cited by experts

[1] Zierer K (2021): Effects of Pandemic-Related School Closures on Pupils’ Performance and Learning in Selected Countries: A Rapid Review. Education Sciences. DOI: 10.3390/educsci11060252

[2] Zierer K (2021): Ein Jahr zum Vergessen: Wie wir die Bildungskatastrophe nach Corona verhindern. Verlag Herder GmbH.