Effective Abstracts in Science Class
T. R. Girill
Technical Literacy Project
trgirill@acm.org
Rev. October, 2018 (WP)
Core Characteristics and Skills
Abstracts are one of those rare literary forms important in real
life as well as just in school (more on that at
the end).
An abstract summarizes a paper (or, in real life, a published
article) in 250 to 500 words, but in a special way.
Abstracts circulate widely independently of the articles
that they summarize (in vast searchable online databases sold
commercially or offered by professional societies).
Hence astute abstract writers have learned the importance of
constructing a compact surrogate for their much larger paper.
A good abstract is brief and entirely self-contained, yet someone
who has never seen the paper that it summarizes should be able
to reliably judge the content and relevance of that paper
(to their own interests) by reading the abstract alone.
Abstract writing thus demands sophisticated text design skills:
- conciseness together with
- a well-honed sense of content priorities, and
- disciplined verbal organization.
So teaching these skills to science students presents special
challenges as well as unusual practical opportunities.
Field-Specific Features
Most high-school students learn about abstracts (first) in
language arts or history class. So what does a good authentic
abstract look like in language arts or history?
That is an empirical question, which Helen Tibbo answered in her
revealing comparative study “Abstracting across the disciplines”
(1992).
Tibbo performed a sentence-by-sentence analysis of 30 abstracts
randomly selected from a “high-impact” (influential, widely
cited) American history journal and compared them with 30
abstracts randomly picked from a high-impact journal in chemistry
(p. 43).
The history abstracts had this content profile:
Percentage of sentences
in each content category
Categories |
History |
Background |
5 |
Purpose/scope |
9 |
Hypotheses |
1 |
Methods |
5 |
Results |
2 |
Conclusions |
14 |
None of above |
64 |
Most real-life abstracts in science and engineering, however, are
very different from this.
Technical abstracts are highly structured and divide their words
very consistently by task.
Tibbo’s analysis of chemistry abstracts, for example, found
this pattern:
Percentage of sentences
in each content category
Categories |
Chemistry |
Background |
9 |
Purpose/scope |
24 |
Hypotheses |
0 |
Methods |
28 |
Results |
22 |
Conclusions |
16 |
None of above |
0 |
In other words, science abstracts strongly reflect the IMRD
(introduction [= background], methods, results,
discussion [= conclusions]) structure of most science reseach
articles, while (even well-written) abstracts in other fields
do not.
Few students draft science abstracts consistent with this
“chemistry” pattern without special coaching.
A likely explanation is that they learned how to craft abstracts
from history or language arts teachers mostly familiar with the
upper (unstructured) pattern rather than the more structured
lower pattern typical in science publications.
The drafting sophistication required together with the highly
structured division of the text means that your students will
probably learn how to write good science abstracts only from
their science teacher (if they learn it at all).
Structured Abstracts
Because the structure of science abstracts is so consistent and
useful to readers, a few technical journals–mostly in medicine
where confusion or ambiguity can have drastic negative clinical
consequences–now make the IMRD chunks of their abstracts
explicit with imbedded headings.
Your students can see other students using this approach
(misleadingly call “structured” abstracts instead of
“labeled” abstracts) at the California State Science Fair
(CSSF) website (go to
http://www.usc.edu/CSSF/History
for a choice of recent years).
Heading details vary by publication (or year) but the usual
pattern involves overtly subdividing the abstract text with
these labels:
Objective/Goal(s)
Materials and Methods
Results
Conclusion(s)/Discussion
Even these slight prompts are seldom deployed, however.
Most professional journals still leave to the scientist (or engineer)
the task of rationing their scarce abstract space among the
IMRD topics to adequately represent the work done and
signaling the abstract’s organization without the help of
any displayed headings.
Few students do this well even if their lab or field work is
strong and interesting.
A Content Checklist for Abstracts
Giving students examples of well-crafted and of ineffective
abstracts is the usual practice to encourage good drafting.
Unfortunately, this assumes that the students can learn from
examples, always a cognitively demanding task and especially
so when the content distinctions are subtle.
Even poor abstracts are often full of “science content,”
but that content is inappropriate to thoughtfully represent
the corresponding paper or report.
Another way to scaffold abstract drafting is with an itemized
list of what science abstracts include and exclude:
When constructing your abstract…
Include |
Exclude |
Your topic or problem (purpose),
but usually not your hypothesis |
Background information (except to briefly frame the problem) |
Scope of work |
Historical details |
Treatment (experimental, theoretical, methodological, practical) |
Literature review, cross references, footnotes |
Novel methods or algorithms
(but always age, sex, genus, species of biological subjects) |
Procedural details, apparatus diagrams |
Key numerical or statistical results |
Equations, formulas, data tables, graphs |
Significance; interesting conclusions |
General principles or trends, common knowledge |
“Keywords”–searchable terms, distinctions, comparisons that
identify your work to others |
Definitions of technical terms |
This chart offers a chance to not only tour the important features
for your students, but to explain why they fall on one side
of the chart or the other.
For example, school science projects often stress testing some
explicit hypothesis, but (as Tibbo’s study confirms) virtually
no published abstracts include this.
Instead, they make clear the purpose of the reported work,
the specific research or design problem addressed.
Readers naturally filter abstracts looking for those whose
reported problems link to their own.
Since students spend much time mastering techniques (“methods”)
new to them but standard in a field, the focus of their work is
often strongly methodological.
Projects with a theoretical or therapeutic focus should point
this out.
Biologists always filter the work of others by organism
studied (hence the mention of subject genus, species, sex,
and age).
And every reader wants to know how a project turned out–the key
quantitative results and their significance from the author’s
perspective.
Abstracts are searched in large databases by keyword, so
smart abstracters take care that their vocabulary contains
those terms and distinctions that others are most likely to
use during such a search.
The exclusion column surprises some students because most items
listed there seem obviously relevant and important.
But an abstract needs to devote its scarce space to the
work at hand, not to general science principles or background
information readily available from reference sources.
Almost all of the other exclusions reflect the text-only
character of abstract databases: diagrams, equations, graphs,
or tables are not plain text (in journals they are often
encoded PDF or TeX) and they will not survive sharing in
plain text formats.
Astute writers learn ways to mention or summarize these
otherwise valuable features using text alone (in retrieval-friendly
ways).
A Science-Abstract Template
More Space Scaffolding
Explicit as the foregoing checklist is, it still leaves many students
confused about how to budget their scarce space in a science
abstract and how to implement the checklist’s content advice.
Those students need a further scaffold of a different kind when
they draft an abstract:
a top-down guide to space allocation.
I find that this template or “action matrix” meets that need well
(click on the chart for a printable PDF version):
Action Matrix for Building a Good Science Abstract |
(1)
Allot roughly this percentage of total WORDS: |
(2)
To describe this TOPIC: |
(3)
Then review the draft and REVISE it to
be sure that:
–These subtopics are included (if relevant).
–These questions are addressed. |
24% |
Purpose: what we sought |
- Goal(s) clear and unambiguous?
- Research/experimental design explicit?
|
24% |
Methods: what we did |
- What was actually measured, and how?
- Any new or improved methods?
- Steps or sequence clear?
- Which controls used? Comparisons?
- Risks, attrition, adverse events disclosed?
- Subject selection, randomization, limits?
- Blinding of subjects? Investigators?
|
24% |
Results: what we found |
- Key numerical/statistical trends revealed?
- Outcome assessment well defined?
- Sample size adequate?
- Calculations or analysis appropriate? Tests stated?
- Explains if no results (yet)?
|
24% |
Conclusions (discussion): so what |
- What is omitted that could mislead a reader?
- Terminology inaccurate, inappropriate, needlessly hard?
- Text too condensed or confusing (for ESL readers)?
- Disorganized or wrongly organized claims?
|
4-5% |
Background: place first but
draft last so you don’t waste too many words here |
- Focused on problem-framing context?
- Acronyms explained, jargon minimized?
|
The matrix assigns to each of the four key topics that a good
science abstract includes (IMRD, col. 2) roughly
one-quarter of the available total words (col. 1).
Although a little “background” comes first, I advise students
to draft it last, using a sliver of space saved from each of the
other topics.
Software makes word counts and percentage calculations easy for
anyone now, so students can give themselves simple quantitative
feedback as they iterate toward this division of space.
Of course, student projects are often not well balanced among the
four IMRD topics–results (or interpretive conclusions) may be
light while (newly learned) methods are disproportionately
important.
So rebalancing the division of space from the even four-way split
suggested here can be quite appropriate: the template still
provides a disciplined framework from which to start.
More Content Scaffolding
A somewhat different problem is that some students are intimidated by
an abstract’s space constraints and include too few details about
any of their specific work.
An abstract is no place for vague generalities, however true they
are.
The template’s third (right) column addresses this problem.
Here for each topic are a few focused questions to prompt
students to include relevant details.
(Not all questions pertain to all projects, of course, but if they
pertain their answers are very interesting to technical
readers eagerly searching for work related to their own.)
The methods row contains the most questions because
(1) students often carelessly overlook their own key
methodological details, and
(2) methods refinements are often more innovative than
results or conclusions in student-level research.
Using this template along with the include/exclude itemized
chart more reliably yields good abstracts than using the
latter alone.
Template cols. 1, 2, and 3 together more thoroughly externalize
the drafting actions that students need to try.
The Authentic Payoff
One really satisfying aspect of teaching students how to design
effective science abstracts is that they are avidly read by
real scientists, not just by teachers grading them in science
class.
And reading such abstracts often has significant practical
consequences.
Henry C. Barry and his colleagues reported a particularly
striking example of science abstract influence in their 2001
article in the Journal of the American Board of Family
Practice.
Barry et al. asked almost 300 family-practice physicians how
they would treat corneal abrasions (e.g., patch or not) and
how they would treat fibromyalgia.
Then these physicians read only abstracts, not whole
research articles, summarizing briefly research done by others
relevant to those conditions.
After reading the abstracts alone, without consulting
the nuanced subject-control discussions and applicability
warnings in the original articles, 76% of the physicians were
willing to change their treatment of corneal abrasions and 73%
would change their use of drugs with fibromyalgia patients.
Because of time pressures in clinical practice, these doctors
routinely scanned abstract databases and adjusted their
therapeutic behavior based only on 300-word summaries of
medical research done elsewhere by complete strangers.
So unlike many things that your students learn (or should learn)
to write in school, science and engineering abstracts have
a high impact on other practitioners in real life.
Introducing students to checklists and templates that promote
abstract effectiveness may therefore increase their influence
on others during their professional lives much more than
many other superficially cogent lessons or techniques.
Abstracts are small but mighty.
Middle School Science Abstracts
Teachers sometimes ask if students can or should learn abstract-drafting
skills before they need them in high school.
Does designing effective abstracts have a place in middle school?
The Need to Learn
One positive answer comes from the Common Core State Standards
(CCSS)
for Language Arts (literacy). CCSS uses the word ‘summary’
rather than ‘abstract’ to identify a concise yet revealing nonfiction
description of a project or a larger technical text.
According to CCSS, starting in grades 6-8, active reading should
involve creating “an accurate summary of the text [read] distinct
from prior knowledge” (RST6-8.2).
Literacy standard W6.5 likewise calls out the skills that
middle-school students need to generate such summaries:
With some guidance and support from peers and adults
[such as an age-appropriate scaffold for designing abstracts,
see below],
develop and strengthen writing as needed by planning, revising,
editing, rewriting, or trying a new approach.
A second positive answer comes from regional science fairs, which
usually accept projects from students in grades 6 to 8, with an
abstract for each one.
The California State Science Fair, drawing upon local fair winners,
even publishes all of its grade 7-8 project abstracts on the
website for its junior division
(linked by topic from
http://www.usc.edu/CSSF/Current/Panels).
One of those student-written abstracts seeds the weaker/stronger
comparison case discussed below (and these examples are available
for every topical area in science).
Content versus Grammar
When coaching middle-school students in writing abstracts, you need
to make clear that critiquing and revising an abstract (a literacy
effort) is different from critiquing or revising the underlying project
described (an effort in technical methodology).
Indeed, some students with clever projects fail to do their own work
justice with inept abstracts that inadequately reveal their
accomplishments to strangers.
Most challenging are abstracts that appear grammatically and
syntactically correct but still do not explain what the student
actually did, found, or thought. A checklist of questions and
weaker/stronger example comparisons
(see below) can help such students develop
a more sophisticated sense of what makes a science abstract
helpful to others.
A Case Study
As a extended example of revising a middle-school abstract to
make it more effective using Common Core literacy skills, consider
this (anonymized) case written to summarize a grade-7 student
project and published on the California State Science Fair site
for 2014:
Middle school sample abstract
The Section Headings
CSSF abstracts always contain explicit section headings, certainly a helpful scaffold for students new to drafting abstracts. Most professional journals omit such subheads, but a few trend setters such as the Journal of the American Medical Association (JAMA) now include them to help their own physician-readers more effectively use each abstract’s content.
Objectives/Goals
Here (see text box above) is a typical instance of completely readable sentences that nevertheless reveal almost nothing about what the student tried to do. What kind of “vegetable” oil? What kind of “plant”? How would they know if the plants really “grew better”?
Consider this possible alternative goal statement:
This project explored whether giving primroses a mixture of olive oil and water instead of water alone increases leaf size.
The revised version is only half as long as the original (20 words instead of 40), yet it includes all of the helpful goal-specifying specifics about this project that the first version omits.
Methods/Materials
The original version (above) gives some details but remains vague (“watered”=?), mysterious (where did the student get the 2.5-ml amount?), and incomplete (how was growth measured?). Including sentences such as those below could address those methods gaps:
I poured a mixture of 250 ml of tap water and 2.5 ml of olive oil into each pot weekly, an amount estimated from liquid fertilizer instructions. I measured the tip-to-tip horizontal size of each plant’s leaves at their widest location with a ruler.
Results
This abstract section summarizes the student’s “average” data, but it fails to reveal its spread (standard deviation for older students) nor say what really counts as plant “growth” (height? width? weight?). Revision along these lines would help:
Water-only plants increased their maximum leaf width on average by 0.85 cm (ranged from 0.6- to 0.9-cm increase) while water-plus-oil plants increased their maximum leaf width on average by 4.57 cm (ranged from 3.5- to 5.5-cm increase).
Conclusions/Discussion
The student in this case understands that interpretation is needed but doesn’t quite know how to explain that “plants will grow better if vegetable oil is added,” nor why their project results could have practical significance. One stronger direction to try would be:
Olive oil contains hydrocarbon molecules (fatty acids) that green plants use as extra nutrients. This could also be tried on food crops.
Tools to Teach With
Different project abstracts in different science areas certainly call for different revisions. But a “structured walk-through” of a case like the one above can reveal possibilities that your young students may never notice without such writing apprenticeship.
One way to share such advice consistently in a structured way that students can review and generalize is with a weaker/stronger checklist organized by the parts of an abstract, such as this chart :
abstracts.midsch2
One step more general is a simplified version of the standard
good-abstract design template
adapted for younger students.
Simplified questions and an easier vocabulary bring these
authentic adult issues to bear on middle-school summary drafting
and revision:
abstracts.midsch1
Just teaching young students that the best abstracts are almost
always created iteratively, with several revision cycles looking
for the kind of increased focus illustrated by the case above,
will greatly enrich everyone’s summary-writing skill.
References
- Barry, Henry C., et al. (2001).
- Family physicians’ use of medical abstracts to guide
decision making: style or substance?
Journal of the American Board of Family Practice,
14(6), 437-442.
http://www.jabfm.org/content/14/6/437.full.pdf
- Tibbo, Helen. (1992).
- Abstracting among the disciplines. Library and Information
Science Research, 14(1), 31-56.