2.1. Problem Posing
The research literature in mathematics education reflects a wide variety of approaches and definitions of what constitutes MPP (
Baumanns & Rott, 2021;
Cai, 2022). In the case of students, and from a broad perspective, MPP can be understood as performing two activities: (i) posing a problem based on a given situation, or (ii) posing a problem by modifying an existing problem (
Silver, 1994). Henceforth, the focus of this study will be on MPP based on a given situation. Taking into account the level of openness the task grants to the problem poser,
Baumanns and Rott (
2020,
2021) distinguish between structured and unstructured MPP tasks. MPP tasks are structured when students are asked to pose problems based on a previously solved problem by modifying some of its structural elements. Tasks are unstructured when students pose problems based on a given situation that may or may not provide detailed information. Thus, MPP tasks form a spectrum in which both the restrictions and the information provided increase, and whose extremes are unstructured and structured tasks. This study focuses on unstructured tasks.
The defining framework assumed (
Cai, 2022;
Baumanns & Rott, 2020) implies that the activity of formulating necessarily leads to the construction of a problem that requires a solution. When recent studies within the framework of problem solving refer to mathematical problems, they do so to describe non-routine problems (
Baumanns & Rott, 2020). However, it is important to note that the terms “task” and “problem” are used in a broad sense in the framework of problem posing, and an MPP task can hence lead to the construction of problems at any point along the routine/non-routine spectrum.
MPP tasks have been conceptualised in the literature as consisting of two fundamental elements: the problem situation and the prompt (
Cai & Hwang, 2023;
Cai et al., 2022). The problem situation sets the context and provides the background information for problem posing. Depending on whether the problem situation is based on real-world or mathematical references, it concerns a real-world or a mathematical context. The information provided by the problem situation can be qualitative or quantitative, and may include words, pictures, graphs, patterns, tables, and mathematical expressions (
Cai & Hwang, 2023). The prompt guides the problem posing process by delimiting the expectations of the task. For the same problem situation, there can be numerous types of prompts, which may include a reference to the number of problems, the difficulty, the person the problem is intended for, or a combination of those prompts.
An MPP task can become more or less structured by making modifications in the problem situation and/or the prompt (
Carmona-Medeiro et al., 2024). The choice of problem situation, and therefore of the context and the amount of information provided, influences the nature of the problems students can generate and the complexity of the mathematical work to be activated (
Montes et al., 2024). Different studies have shown that the type of prompt has a direct impact on the characteristics of the problems students pose (
Cai et al., 2023).
We know that the cognitive processes involved in problem posing have their own specific nature and, therefore, cannot be effectively described using traditional phase models of problem solving (
Cai & Rott, 2024;
Pelczer & Gamboa, 2009). Although there is still no general descriptive model of phases for problem posing comparable to Pólya’s four-step problem-solving model (1985), several studies have attempted to characterise its phases (
Baumanns & Rott, 2022;
Cai, 2022;
Cruz, 2006;
Koichu & Kontorovich, 2013;
Pelczer & Gamboa, 2009;
L. Zhang et al., 2022).
In particular,
L. Zhang et al. (
2022) propose that the processes involved in problem posing can be framed in three phases: (i) understanding the task, (ii) constructing the problem, and (iii) expressing the problem. Given the nature of this study, focused on identifying students’ difficulties during a problem posing task, attention is placed on two of these phases: the students’ understanding of the task and the oral expression of the posed problem.
The understanding of the task phase constitutes a key moment in the problem posing process, as it does not merely involve interpreting instructions but requires an active exploration of the problem situation to identify its mathematical potential. According to
Baumanns and Rott (
2022), this initial phase, which they call situation analysis, is crucial for generating mathematically meaningful problems, as it allows students to establish connections between the elements present in the problem situation and the underlying mathematical structures. Moreover,
L. Zhang et al. (
2022) note that cognitive conflicts arising during this phase act as creative triggers in the process of posing problems. Other studies (
Cai & Rott, 2024;
Crespo & Sinclair, 2008) highlight the importance of students becoming familiar with the task in order to recognise its limitations and possibilities, concluding that a prior and thorough exploration of the problem situation positively impacts the quality of the problems posed. However, identifying the opportunities the task offers, considering its conditions, constraints, and mathematical potential, is neither immediate nor self-evident, but requires deliberate interpretation and selection by the students (
Pelczer & Gamboa, 2009). In the case of early childhood education, several studies (
Martín-Díaz et al., 2020;
Carmona-Medeiro et al., 2024) reveal that exploring the problem situation is essential for the viability of the task.
The problem expression phase, on the other hand, requires students to organise their ideas and articulate the language needed to shape the problem they have devised clearly and precisely (
Baumanns & Rott, 2022).
Crespo and Sinclair (
2008) point out that the ability to express mathematical problems not only reflects understanding of the content, but also the ability to communicate mathematical ideas effectively. In the case of students under the age of six, studies indicate that limitations inherent to the development of literacy and linguistic skills (
Carmona-Medeiro et al., 2024;
van Bommel et al., 2024) affect the written or oral formulation of the problem. Thus, the expression phase becomes particularly sensitive in early childhood education, where communication difficulties may influence the quality of the problem posed, regardless of the students’ level of mathematical understanding.
2.2. Characteristics of the Problems Posed: An Indicator of Students’ Difficulties
MPP is a cognitively demanding activity (
Cai & Hwang, 2023;
Silver, 1994). Unlike problem solving, MPP, in general, is an activity that is far removed from the usual classroom habits (
Chen & Cai, 2020;
Singer et al., 2013). Its integration in the classroom is a challenge for both teachers and students, as it involves a disruption of prevailing rules and expectations of teaching and learning mathematics (
Cai et al., 2015). To make progress in understanding how to integrate MPP in the classroom, it is necessary to understand which factors influence its implementation (
Cai et al., 2015;
Carmona-Medeiro & Climent, 2024). Although studies focused on ECE indicate the feasibility of introducing MPP (
Carmona-Medeiro et al., 2024;
Fosse et al., 2020;
Martín-Díaz et al., 2020;
van Bommel et al., 2024), little is known about the difficulties experienced by ECE students during MPP. The study conducted by
Carmona-Medeiro and Climent (
2024) on understanding how a teacher manages an MPP task in an ECE classroom (4–5 years) can be considered a direct antecedent of this study. The study reveals that most of the students’ difficulties involving teacher scaffolding are related to the students’ prevailing non-mathematical meaning of problems.
It should be noted that, at this age, children are in the process of learning how to read and write, for which reason the problem situation should provide information in a register other than the written one. Therefore, the choice of the register to be used to provide the problem situation is not random. Obtaining information from the students may represent a potential difficulty linked to the different registers that can be used for the choice of the problem situation. Most of the studies on MPP in ECE (
Carmona-Medeiro et al., 2024;
Martín-Díaz et al., 2020;
van Bommel et al., 2024) provide the problem situation using registers that encourage manipulation and/or visualisation. It is known that manipulative and visual experiences are essential as a basis for verbal and cognitive development at these ages (
Smith et al., 2011). However, little is known about the difficulties students experience in obtaining and communicating information from the problem situation.
Analysing problems posed by students is not only an avenue for assessing mathematical performance, it can also be an indicator of their emerging difficulties (
Cai et al., 2015). Multiple approaches that analyse problems posed by students (
Cai & Hwang, 2023;
Carrillo & Cruz, 2016;
Leavy & Hourigan, 2024;
Palmér & van Bommel, 2020) have been considered in this study. Adaptations were made because of the peculiarities of children. Thus, with the focus on children’s difficulties, three variables are considered to characterise the problems posed: (i) mathematical nature; (ii) incomplete problems; and (iii) inconsistent problems.
The “mathematical nature” variable is in line with the difficulty
Cai (
2022) mentions, and refers to whether the problem posed is set in a framework in which the mathematical concepts or procedures necessary to solve the (mathematical or non-mathematical) problem are located. The “incomplete problems” variable refers to the absence of some of the structural elements of the problem posed (information and/or question) (
Carmona-Medeiro & Climent, 2024). Finally, the “inconsistent problems” variable addresses both the problems posed in which there is no logical relationship between the information and the question, and those that are unrelated to the current problem situation and/or prompt (
Cai, 2022).
In light of recent studies (
Baumanns & Rott, 2022;
Cai & Rott, 2024), it is relevant to distinguish between the processes involved in MPP and the products resulting from it. The former refers to the cognitive, linguistic, and interactional actions students perform throughout the problem posing activity, whereas the latter concerns the structure and mathematical quality of the posed problems. This study considers both dimensions: the analysis of the posed problems and the emerging difficulties identified during the activity, each offering a complementary perspective on students’ engagement with MPP.