Does the sentence sound reasonable and unambiguous? What is one problem with the previous sentence, given the evidence cited in the section on Graphical Frameworks?
The problem with the sentence is not that it conflicts with the majority of available evidence. The problem is that the sentence is ambiguous. We can think of a number of questions that the sentence does not address: For what types of tasks (e.g. academic, motor, etc.) does serial practice lead to higher test performance than blocked practice? Does serial practice lead to higher test performance for all kinds of people (e.g. old, young, etc.)? Does the level of experience of a learner (e.g. novice vs. intermediate vs. expert) affect the benefits of serial practice? Does the time when test performance is assessed (e.g. during practice vs. immediately after practice vs. days or weeks later) affect the benefits of serial practice? And many more. Each question introduces a different possible interpretation of the sentence.
In essence, the sentence "Serial practice leads to higher test performance than blocked practice," makes a strong, categorical statement that implies: "serial practice always leads to higher test performance than blocked practice," which is simply not true. The sentence needs to be more specific.
Imagine that to make the sentence more specific, the student writes: "Serial practice usually leads to higher test performance than blocked practice."
By specifying that serial practice doesn't always lead to higher test performance, does including the word "usually" solve the problem? Clearly not, because all of the questions about the first sentence still apply. Moreover, the word "usually" is a vague term, and does not indicate what "usually" means (i.e. how often, exactly?). Instead of making the sentence more specific, the student has made the sentence even more vague.
The student might then decide to revise the sentence to read:.
"Most studies have found that serial practice leads to higher test performance than blocked practice."
Has the student made the sentence more specific? Yes, specifying that "most studies" have found higher test performance with serial practice is more specific than the first sentence. However, there is a problem with the student's choice of specifics: the student has now written a sentence that they cannot defend.
Stating that "most studies" have come to a similar conclusion implies that the author knows that over 50% of studies support the conclusion. To know that over 50% of studies support a conclusion, the author would need to find ALL of the research on a particular topic, read every study, and find that 50% or more of the studies support the conclusion. Even the most experienced scientists in a field are often not confident that they have read ALL the research reports in a field. Therefore, it is highly unlikely that a student has found and read all of the research necessary to make the statement the student made. We do not know that the statement "Most studies" have found something is truthful. Therefore, simply making statements more specific is not sufficient. Sentences must be both unambiguous and truthful.
To make a statement about serial practice and blocked practice, the student must provide enough context so that a reader can faithfully interpret the sentence. For example:
"Serial practice can result in higher performance on retention tests than blocked practice for students learning mathematical concepts (Rohrer et al., 2014)."
2) Specific writing is self-contained.
DEFINITION: In the context of communication, "Self-contained" means that each element (e.g. paper, section, paragraph, sentence) of a presentation either (A) contains all of the information reasonably needed to understand the element, or (B) is part of a framework that contains all of the information reasonably needed to understand the element in such a way that the interpretation of the element unambiguous.
For example, imagine a student who writes a sentence in a paper about exercise:
"This causes sodium levels in the blood to decrease to dangerous levels."
Can you understand the student's sentence? The sentence is difficult to understand because we don't know what "This" refers to. "This" could refer to the sentence before, or three sentences before, or somewhere else in the document. We CANNOT know what "This" means from the sentence itself: the sentence is not self-contained.
Similarly, students often write sentences in the Discussion that are similar to the sentence:
"The data support our general hypothesis."
Without specifying the data being referred to, or what the general hypothesis is, is is impossible to for the reader to be sure which data support what hypothesis. Without an explanation of why specific data support a clearly-stated hypothesis, the Discussion section is not self-contained and not sufficiently specific.
Specific scientific communication seeks to prevent audiences from needing to make ANY guesses about the meaning of each statement (Pechenik, 2016).
Specific scientific writing also minimizes the need for readers to refer to other parts of a document to understand a written element (e.g. sentence or paragraph). For example, a student may develop three General Hypotheses for a paper in the Introduction, and number them "Hypothesis 1," "Hypothesis 2," and "Hypothesis 3." In the Discussion, the student might write a sentence such as:
"The significant difference in throwing accuracy between the trained and untrained groups supports General Hypothesis 1."
Although the sentence is unambiguous and does not require the reader to guess which hypothesis the student is referring to (which is good), the sentence does require the reader to either remember the hypothesis or refer back to the Introduction. A more specific approach would be to re-state the hypothesisbefore explaining why the data support the hypothesis. Re-stating the hypothesis not only helps make the Discussion more self-contained, but can also help to emphasize the importance of the hypothesis through repetition.
Similarly, using acronyms to condense frequently-used word phrases can be very useful to reduce the amount of text in scientific writing. However, if a manuscript uses many acronyms, it is helpful to provide a reference table with brief definitions of each acronym.
3) Constructing frameworks (e.g. arguments) from self-contained, unambiguous statements helps to ensure that the frameworks themselves are unambiguous.
Somewhat analogous to the "truth preserving" nature of valid deductive reasoning, arguments can be "specificity preserving." If the premises are specific and the framework is strong, then an overall argument is likely to result in a conclusion that can also be considered specific. For example, consider the argument:
DEFINITION: Interleaved practice involves alternating practice trials of two or more different topics. For example, interleaved practice of topic A (trials A1, A2, and A3) and topic B (trials B1, B2, and B3) would practice trials in the order A1,B1,A2,B2,A3,B3 (Rohrer, 2012).
PREMISE: Interleaved practice can result in higher performance on retention tests than blocked practice for undergraduate students learning to differentiate between paintings by two artists (Kornell and Bjork, 2008).
DEFINITION: Retention tests demonstrate that increases to performance persist over time, indicating that performance increases reflect learning (Shea and Morgan, 1979).
PREMISE: Interleaved practice can also result in more learning than blocked practice for 7th grade students studying two contrasting mathematical concepts (Rohrer et al., 2014).
PREMISE: However, blocked practice results in more learning than interleaved practice for undergraduate students using induction to learn how how to correctly pronounce similar French words (Carpenter and Mueller, 2013).
CONCLUSION: Therefore, our General Hypothesis is that interleaved practice is better than blocked practice for learning that involves contrast, but not better than blocked practice for learning that only involves induction.
Without the supporting premises, the conclusion would be vague. However, the specific premises provide a framework with the information necessary to understand what "interleaved practice" is, some types of tasks that involve contrast, and one type of task that only involves induction.
Specificity is necessary for clear scientific communication. Construct arguments using a strong framework and unambiguous statements. Make sure that each element is self-contained, or within a self-contained framework that makes the meaning of the element unambiguous.