Curriculum development can be perceived as the permanent search for qualitative improvement of the relevance and feasibility of the curriculum, in response to changes in society (Bude, 2000). However, changes in education are likely to fall behind the changes taking place in the real world. This problem is referred to as the time lag dilemma, and is considered a challenge for a country’s curriculum reform agenda. A major aspect, immediately related to this time lag dilemma is curriculum overload. Curriculum overload, sometimes referred to as “curriculum expansion” or “curriculum overcrowding”, occurs when society keeps adding new topics to the school’s curriculum, without removing others or changing the requirements. Teachers and students experience curriculum overload as undesirable, because it affects the quality of teaching and learning and may result in a shallow exposure to subjects. Perceptions of time lag dilemma and curriculum overload may vary from country to country. This is partly due to the way the curriculum is regulated in a jurisdiction (Kuipers, Nieveen & Berkvens, 2013) leading to more or less opportunities for curriculum-decision making at school and classroom level.

In this paper we connect two literature review studies, which we conducted in the frame of the OECD2030 project (OECD, nd). One of these reviews focused on time lag dilemma, the other on curriculum overload.  To conceptualize time lag in the frame of curriculum development we used Halinen’s (2017) four dimensions of time lag 1) recognition lag (identification of societal challenges), 2) decision-making lag (the organization of planning/decision making with respect to (future) demands), 3) implementation lag (how quickly and how well goals are implemented in classroom practice and 4) impact lag (how quickly and how well the results of the reform can be found in students’ learning). Curriculum overload typically occurs during curriculum planning and during curriculum implementation. In the curriculum planning phase overload may occur when intentions are too detailed, when new content and goals are added to the curriculum without removing existing content and goals, or when the new curriculum is not aligned with assessment practices. According to Boersma (2001, 2009), curriculum overload as experienced by teachers typically occurs during curriculum implementation and can be framed as a discrepancy between available teaching time and the content that has to be taught and between available time and teachers’ standards to guarantee curriculum quality. In this paper we particularly focus on issues of time lag and curriculum overload that occur during curriculum planning and curriculum implementation (Halinen’s 2nd and 3rd dimension) with the aim to identify interferences between time lag and curriculum overload in curriculum development processes. This leads to the following questions:

1. How is time lag handled in curriculum planning and implementation processes?

2. Which elements in curriculum planning and implementation contribute to curriculum overload?

3. How do issues of time lag and curriculum overload interfere in curriculum planning and implementation processes?

Two reviews of the literature on respectively time lag and curriculum overload, both related to curriculum renewal processes, have been conducted. To determine the dataset for the reviews a search process was conducted using well-known databases (e.g. ERIC, Web of Science). In addition to this formal approach we used our network to find additional sources. This resulted in 21 publications related to time lag published between 2006 and 2017 from eleven different jurisdictions. For curriculum overload 28 publications were found from twelve different jurisdictions and published between 2003 and 2017. These studies were summarized using a template, which captured background information (author(s), date of publication, title and jurisdiction); abstract; context of the study (including regulation policies when appropriate) and specific conclusions about problems experienced with curriculum overload and strategies to deal with these problems (when provided). To organize the findings of the studies we used the four dimensions of time-lag and focused in our analysis on problems that were identified and strategies that were used to overcome these problems.

Quality curriculum development takes time. About 2-4 years are needed for the planning (including the recognition phase) and decision-making alone. Countries have different traditions in how they organize curriculum planning and decision-making. We found politically-driven ad hoc approaches and ongoing curriculum renewal processes with room for schools to respond more quickly to changes in society. Major causes of curriculum overload during planning and decision-making found are: too many and too detailed documents; too many additions; and lack of coherence. An overarching curriculum framework is considered a promising strategy to prevent an uncontrolled expansion of the curriculum. The implementation oftentimes does not match the curriculum intentions of the previous phase due to reduced perspectives on the curriculum’s intentions, feelings of overload and simplification of the teaching of complex concepts and skills.. Piloting and monitoring of the new curriculum is needed to fine-tune curriculum decisions. . Teachers need time to adopt and understand the underlying curriculum rational. Support, in the form of guidance and exemplification is needed to make sense of the curriculum at the local/school level. But when support is experienced as prescription or is too overwhelming, feelings of overload may be the result. Finally, we found that to prevent perceptions of curriculum overload and create ownership for the new curriculum teachers need to be actively involved in all phases of the curriculum renewal process. This is easier to realize and more time efficient when the planning and implementation phase of curriculum renewal processes are more interwoven.

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