Summary
This paper reviews the different perspectives on STEM education, STEM skills, curriculum and methodologies, knowledge about STEM disciplines and STEM literacy. Based on the review, it then proposes a framework to guide STEM education in schools.
On the subject of STEM education, they talk about the opportunity we have in view of the investments that are being made by governments to promote STEM methodology from a business point of view. They mention authors who warn us about this issue and the danger that this may entail and the importance of incorporating the critical point of view of the students into the proposals. The proposals must be related with the real world and suggests there are multiple equally valid discipline ‘entry points’. The assessment requires a balanced approach engaging formative, provisional and summative methods.
Related to STEM skills they said that there are soft skills (cognitive, creative, personal capabilities and dispositions and attitudes) and hard skills related specifictly with subjects. They suggest that learning enviromets play a significant role in facilating or contracting STEM skills environment.
Reagarding to the curriculum and pedagogy, authors identify design thinking as the metodology to implement STEM projects. They said that should be multi or interdisciplinary designs. Encourage to include access to external information networks and engage to the project comunity groups or businesses.
Discipline orientation varies so much depending the authors and it depends also on the school levels. There two different point to take into account: Teachers, that don't feel confidence in some of discipline-specific contents and the need to report the assessment for each subject.
About STEM literacy they cite Bybee (2010).
They said STEM literate and STEM literacy aren fundamentally different.
Literacy demands more than knowing "how" to do something and how to apply knowledge in practice. They claim that education must develop students' STEM identity that empowers them to use their STEM capabilities in ways that have a positive impact and effect.
The framework authors propose, contains all the aspects that a STEM literacy proposal should take into account in the design. (See figure 1)
As conclusion, authors encourage to designers to take into consideration different approaches, strategies and roles. They said that making adjustments to historical organization to improve flexibility, colaboraboration and discipline integration is needed to support new PBL STEM pedagogies. They present their framwork as an a starting point of discussion about how existing curricula might begin the transition from isolated to multiple disciplines in projects holding a greater authenticity and relevance. They said that this review revealed much debate about this.

Relevance for Complex Systems Knowledge
PBL methodology is proposed using real world enviroments and design thinking principles.
They propose multi or interdisciplinary design approaches
The conclusions are presented in the last paragraph of the summary.
No comments about gender issues or circular economy.

Point of Strength
The proposal of the framework

DOI
https://link.springer.com/article/10.1007/s10956-020-09823-x

Keywords
STEM; Interdisciplinary; Integrated; Discipline; STEM literacy; School k-12