Table 1 The Hypothesis of Learning Progression of Scientific Explanation based on the PTDR Framework

Phenomenon

Affirming and describing the phenomenon. [The phenomenon is clear; it has single variable or has a few variables but their relationship is simple; the changing pattern is conform to everyday experience.]

Theory

Applying scientific ideas, law-like sentences, etc. under the scaffold from teacher or instructional materials.

Using the key variable as the clue for independently selecting scientific concepts, laws, theories and principles.

Independently selecting the scientific concepts, laws, theories, and principles by systematically analyzing the context.

Data

Searching data in a small data set.

Searching data in a big data set.

Defining the data set.

Data set is limited to appropriate data

Data set is ready for directly processing

Data is collected by directly observation, measurement, etc.

Data is collected by indirectly observation, measurement, etc.

Reasoning

Making basic logical connection between idea, data, and phenomenon, though generalization, induction, or simple causal reasoning.

Developing a causal chain or clarifying the mechanism that connecting phenomenon, evidence, and theory, though scientific reasoning including isolation and control of variables, correlational reasoning, probabilistic reasoning, etc.

Designing a unification model that connecting phenomenon, evidence, and theory, though scientific reasoning including but not limited to isolation and control of variables, combinatorial reasoning, probabilistic reasoning, hypothetical-deductive reasoning, etc.