The Science Of Scientific Writing    Set 6     Set 6-Basis boxes Second pageThird pageExampleExercise 1Exercise 2Exercise 3Exercise 4-Quiz 1Fourth page Exercise 5-Quiz 2Writing about EvidenceExercise 6Arguments and Explanations Final page Set 6.

Course Home

OVERVIEW: The way to well-written science

How to do the Course


PART I: Paragraphs and Sentences

SET A: Paragraphs: The Maps Behind Them

SET B: Paragraphs: Using Maps to Meet Readers' Expectations

SET C: Paragraphs with Something Extra: Points and Tails

SET D: The Generic Section: Expectations and Maps as Blueprints

SET E: Scientific Sections: The Methods and Results

SET F: Scientific Sections: The Discussion

SET G : Scientific Sections: The Introduction

SET H : Sentences

SET I : The Paper as a Whole



PART II: The Paper and its Sections


SET 1: Argument Parts

SET 2: Indicator Words

SET 3: Refining Claims

SET 4: Locating Arguments in Prose

SET 5: Rationale's Essay Planner

SET 6: Evidence in Arguments: Basis Boxes

SET 7: Assessing

SET 8: More on Assessing

SET 9: Analysis Maps

SET 10: Assessing Again

Synthesis 1: Position-Early Paragraphs

Synthesis 2: Position-Final Paragraphs

Synthesis 3: Writing a Discussion I

Synthesis 4: Writing a Discussion II

Set 6 - Evidence in arguments: Basis boxes

In the course until now, all claims, reasons and objections on our maps have been given, to some extent, equal visual "weight", in that they each get their own individual item box.Likewise, when we have written up our arguments in text format, each claim/reason/objection has typically acquired, at the most basic level, equal text "weight". Each item is typically delivered in an individual sentence (or perhaps a fully 'independent' clause, within a two-clause sentence).

But in interpreting an argument, or writing it up, some individual items, and branches, carry more weight than others. We need to know how to:

  1. evaluate which items or branches have more argumentative strength than others.
  2. make the differences in argumentative strength visually obvious on the map.
  3. use the argumentative strength of items and branches as a guide to organising the written argument.

In Set 6, we will focus on just one aspect of evaluating argumentative importance - the presence and strength of an argument's evidence. We will also look at how we can make evidence visually obvious on a Rationale map, and how we can write about it in a text.

Solid foundations: the importance of evidence in arguments

When we compose an argument map we start at the top and work our way down. When we evaluate a completed map we switch into reverse, and start from the very bottom of each branch-line. The very first thing we want to assess is the bottom item box in each branch-line, to see if it provides that branch-line with a foundation.

What do we mean by a foundation? In most arguments, and definitely in most of those from science, a branch-line will only be considered as having a foundation if the statement in its bottom item box has a basis in evidence.

Most people have an accurately intuitive awareness of what constitutes evidence, but are often a little confused as to the precise relationship beteen evidence and reasons. To help in explaining this, compare your reactions to the paired sets of statements below.


What reasons can you offer to support your claims?
What evidence can you offer to support your claims?
We need to formulate reasons to support our hypothesis.
We need to formulate evidence to support our hypothesis.

Most people feel happy with all the statements except the very last one. This tells us that while all items of evidence are reasons, many reasons are not items of evidence. Or, put another way, items of evidence exist as a special sub-set of the larger set of all reasons. Their distinctive feature is that they are more-or-less verifiable in the "external world", i.e. outside the head of the person making the argument! In many a courtroom drama in movies this distinction is driven home when the Defence addresses the jury like this:

"The Prosecution has presented a logical, elegant and morally-exhilirating case against my client; it is with the utmost regret that I note how utterly it lacks any evidence, at all, to support it."

If we use the home construction metaphor, evidence is usually referred to as the bedrock that provides the building with a proper foundation. Irrespective of how well constructed a house is, if it does not rest upon solid foundations, it is always in danger of collapsing.

Important Note: when talking about arguments we will use the word "evidence" in a more general sense than a scientist typically would. For example, in this course, both an expert's reported opinion on a topic, and any data the expert might have published in support of that opinion, are evidence. A scientist would probably only think of the latter as proper evidence. What both "evidences" share, however, is that they are externally verifiable: we can, in principle, either refer to the expert's publication (maybe even repeat the experiment) or confirm, by interview, that the expert did say what was reported. It could be argued that scientists themselves resort to using "the weight of expert opinion" when they cite previous papers to support a point, without detailing the actual evidence those papers provide.

Now consider this map:

This argument, like that of the movie-world Prosecutor referred to above, is also very well-structured: as we descend, the focus gets ever-more specific; and the central statement is thoughtfully phrased, allowing the reasons of the bottom tier to nest comfortably below it. But when you, as a critical thinker, carefully examine those three bottom-most boxes, you should find yourself asking questions such as:

- How far can I trust the map-maker's claims?
- Where can I check out the truth of the claims?

Basically, none of the bottom-most claims contains any reference to anything verifiable in the "external world". Now compare it to the expanded map below, and see how the strength of this argument can be upgraded by the addition of supporting evidence.


The three bottom-most boxes raise the argument to a whole new level. This qualitative shift in persuasiveness occurs because we are no longer relying on the say-so of the argument's creator - we can hop on the Net ourselves and begin to hunt down the cited references. This argument has a foundation, a basis in externally verifiable statements.

Evidence in an argument is so important that Rationale has a special type of box just for reasons that deliver it. These are the blue "basis" boxes, and one category of these ('Publication') is used in the Bananas map shown above. The icons used in basis boxes help to emphasise the critically important contribution of evidential statements.

It is not good enough to note that an argument provides us with evidence we must also consider how strong that evidence is. As a very critical thinker, as you must be in science, when you look even more carefully at the evidence provided above, you should find yourself pondering such issues as these:

  • How reliable were the analytical methods of the early 20th century?
  • What are the actual quantities of Vitamins A and C reported as being "high" in the Reynold's book?

....and from a more general perspective, you should appreciate that you are not seeing the evidence itself, but only reports of its existence. This is very common in science. At best we see photographic images of evidence (e.g. of a cell down the microscope, or of a gel after protein electrophoresis) but more typically we see even more highly processed reports of the evidence, e.g. as graphs or tables.

NOTE: One weakness of Rationale, with respect to scientific arguments, is that it currently does not allow one item of evidence (i.e. one basis box) to be placed under another. Of course, in scientific arguments, the great majority of item boxes will contain information with some evidentiary basis. This does not mean we can't use Rationale for scientific arguments - but it does mean we can't use basis boxes. Nevertheless the following exercises are still of use, because they emphasise the importance of evidence, and they also highlight the variety of different types of evidence. Many of these, even ones that a sceintist would not strictly call evidence, are used in scientific papers. For example, scientists will often go out of their way to cite a paper by a well-known scientist (or from a highly respected journal) in which case they are may be utilising that source as much as an authority as a source of relevant data-based evidence.

In this set you will learn how to add bases to your arguments and how to evaluate their contribution to your argument's strength.





Content of this page drawn in whole or part from the Austhink Rationale Exercises with permission from Austhink.