APPENDIX
TOOL
A HANDBOOK OF TECHNICAL REPORT WRITING
FOR MECHANICAL AND AEROSPACE LABORATORY CLASSES
Prepared in consultation with the Mechanical and Aerospace
Department Laboratory Committee
By
Dennis R. Perry
Associate Professor of English
Department of Mechanical and Aerospace Engineering
and Engineering Mechanics
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INTRODUCTION
The purpose of this handbook is to set out some basic guidelines for written reports in laboratory
courses in the Mechanical and Aerospace Engineering department. The contents of this manual
provide general report format guidelines, suggestions and reminders concerning common style
problems, and insight into the writing process, particularly as it relates to the demands of technical
reports. The goal is to present a minimum of examples in a limited outline of essential helps that
clarify departmental expectations for laboratory report writing. This is not intended to replace
standard technical writing handbooks, the scope and breadth of which would be impossible as well
as undesirable to reproduce here. It is recommended that students obtain such a handbook for
handy reference. (Among other sources, I relied on Brusaw, Alred, Oliu, Handbook of Technical
Writing, 4th edition, St. Martin's, 1993 in the preparation of this handbook.) Be sure to read
carefully the particular report assignment instructions for your individual laboratory course.
Underlying the information in this handbook is the fact that research and report writing are
separate activities. Experimental/design research requires precise methodologies in order to yield
results, a process that involves its own set of problems to be solved. Communicating that process
and its results in a technical report involves equal care and precision to solve a different set of
problems. Since research results do not come with a rhetorical formula attached, those results need
to be organized and composed in a manner that will communicate clearly to interested audiences.
In the classroom, that audience includes your professor and GTA; in industry, that audience may
include peers, supervisors, executives, contractors, accountants, lawyers, and many more. It is
simply not enough, in industry or in the classroom, therefore, to arbitrarily report undigested
research data under generic headings. In industry such reports are returned or rejected; in the
ME/AE labs reports are evaluated in terms of both research content and communication
effectiveness. (See Appendix A for a list of correction and proofreading marks.)
Hence, this manual underscores the need to be as rigorous about communicating research as in
doing it. After all, without the ability to communicate your research effectively, the research
ultimately is of little practical value.
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CONTENTS
1 Report Format
1.1 Spacing......................................................................................................................................4
1.2 Topic Headings .........................................................................................................................4
1.3 Margins .....................................................................................................................................4
1.4 Typeface....................................................................................................................................4
1.5 Pagination .................................................................................................................................4
1.6 Graphic Aids .............................................................................................................................4
1.7 Tech Memo Heading.................................................................................................................4
1.8 Documentation..........................................................................................................................5
1.9 Numbering ................................................................................................................................5
2 Writing Style
2.1 Point of View ............................................................................................................................6
2.2 Tense .........................................................................................................................................6
2.3 Varieties of English...................................................................................................................7
2.3.1 Telegraphic Style .......................................................................................................7
2.4 Sentences
2.4.1 Sentence Fragments ...................................................................................................7
2.4.2 Sentence Length.........................................................................................................7
2.4.3 Active/Passive............................................................................................................7
2.5 Parallelism.................................................................................................................................7
2.6 Paragraph Coherence ................................................................................................................8
2.6.1 Transitions...................................................................................................................8
2.7 Gobbledygook...........................................................................................................................8
2.7.1 Nominalizations .........................................................................................................8
2.8 Mechanics
2.8.1 Capitalization ..............................................................................................................8
2.8.2 Colons and Semicolons...............................................................................................8
2.8.3 Quotation Marks .........................................................................................................9
3 Writing Process
3.1 Preparation ................................................................................................................................9
3.2 Research....................................................................................................................................9
3.3 Organization..............................................................................................................................9
3.4 Writing a Draft..........................................................................................................................9
3.5 Revision ....................................................................................................................................9
4 Report Segments
4.1 Executive Summaries..............................................................................................................10
4.2 Tech Memo/Opening Component
4.2.1 Opening vs. Discussion Components ......................................................................10
4.2.2 Results vs. Conclusions vs. Recommendations ......................................................10
4.2.3 Experimental Procedure/Methodology ....................................................................10
4.2.4 Results......................................................................................................................10
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4.3 Professionalism .......................................................................................................................11
Appendix
A Correction and Proofreading Marks
1. REPORT FORMAT
You will want to design your technical reports to be simple and uncluttered and to highlight its
structure by a variety of headings and sub-headings and through the use of white space. By these
means you create easily noticed and processed chunks of text.
1.1 Spacing
Single space, with double spacing between paragraphs, is the convention most often
observed. Your professor, however, may ask you to double-space the entire report in
order to facilitate the written evaluation of your report. When double spacing, maintain
same spacing between paragraphs.
1.2 Topic Headings
For the shorter "tech memo," use headings (or heads) for "Introduction," "Results," etc. It
would be effective to use all capital letters (perhaps even bold) and center or left-justify
the heading double-spaced above the text. For longer reports, vary the style of headings
and sub-headings so that hierarchal relationships between sections are clearly evident.
Also for formal reports, headings and sub-headings should be subject specific ("Testing
Bench" rather than "Discussion").
1.3 Margins
Keep a uniform 1" margin on every page (left, right, top, and bottom).
1.4 Typeface
You should not use more than two families of typeface in a document. Either 10 or 12
point is appropriate (10 is the most common).
1.5 Pagination
After the first page of the tech memo, number each page. Page numbers are most often
placed in the middle top, middle bottom, or upper right corner.
1.6 Graphic Aids
Graphic aids, including tables and figures, are used to replace extended explanation and
description. Use them whenever they are the clearest and easiest means to communicate
technical information. In the tech memo place them at the end as an appendix; in longer,
formal reports place them at the point where you mention them for the first time.
Graphic aids require specific, descriptive titles and numerical identification: note the use
of capitals in the parenthetical example following (Figure 2: Acoustic Levitation
Furnace). Never identify a graph generically as " Y vs. X."
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Graphic aids should be clear and neat, and should be produced from the computer.
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1.7 Tech Memo Heading
There are many ways of doing memorandum headings. Commonly they are left-justified
and appear as below:
DATE:
April 1, 1994
TO:
Lucille McNamara, Vice President
FROM:
Bradly Horton, Research Engineer
SUBJECT: Experimental Results of Wind Tunnel Experiment
Note the double spacing, two left margins, the positions of the individuals named, and the
specific, descriptive subject (using capitals in the manner of a paper title).
1.8 Documentation
If you need to make reference to previous related research, first mention it parenthetically
in the text (Davis and Jefferies 159). Then at the end of the report, include a "Works
Cited" page in which you alphabetically list articles and books mentioned in the text.
(See a standard handbook for specific format options.)
1.9 Numbering
Arabic numbers, associated with headings, are the most standard numbering system used
in technical writing. The following outline suggests how they are used to represent
structural relationships among ideas. Never go beyond three numbers, or two decimal
points.
3
3.1
3.2
4
4.1
4.2
4.2.1
4.2.2
These are used in formal reports, not in the tech memos.
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2. WRITING STYLE
Style refers to the way one uses words to communicate, including word choice and order,
punctuation, point of view, transitions, etc. Technical reports are most useful that employ a style
that is exact, concise, direct and clear.
2.1 Point of View
Point of view refers to the writer's relation to the information presented. The usual
choice confronting report writers is whether to use the impersonal or personal point of
view. In recent years the personal has become more common among effective technical
writers because the impersonal point of view too often leads to an awkward and wordy
style that hinders communication. It is best, therefore, not to substitute "one" for "I"
when you are really talking about yourself, or substitute "the writer" for "I." Both tend to
sound pompous. In addition, only use "we" when speaking in behalf of others. On the
other hand, sometimes the impersonal style can be appropriate, especially when the
information presented needs to get the emphasis ("The evidence suggests that the
absorption rate is too fast") or when you are writing to a large group. For experimental
tech memos it is best to emphasize the information itself but avoid the pitfalls of the
impersonal style. While limited reference to yourself may be appropriate, do not over do
the use of "I."
2.2 Tense
Technical report writing employs the whole range of verb tenses, including (but not
limited to)
1. Past (I began),
2. Past perfect (I had begun),
3. Present (I begin),
4. Present perfect (I have begun),
5. Future (I will begin),
6. Future perfect (I will have begun).
The simple rule is to use common sense, using verb tenses that reflect the situation you
are expressing at the moment. In the tech memo, for example, the introduction may use
present ("The purpose of this report is . . ."), past ("The results were . . ."), and future ("I
will explain . . .").
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2.3 Varieties of English
Technical reports use Standard English (American Edited English--"formal"), with its
exacting standards of punctuation, spelling, diction, usage, etc. Avoid colloquialisms and
vernacular usage ("it worked pretty good"), the more relaxed choices that usually
characterize most spoken English. Also, for the formal and direct style required in
technical writing, avoid using slang, contractions, and story-telling. The latter tends to be
indirect and wordy.
2.3.1 Telegraphic Style: In your efforts to meet rigid page requirements or to write
abstracts, avoid the temptation to use a telegraphic style that condenses writing by
omitting articles, pronouns, and conjunctions (change "in experiment assumptions not
made," to "in this experiment no assumptions were made"). Resumes are one exception
to this rule.
2.4 Sentences
2.4.1 Sentence Fragments: Fragments are very common errors in which a dependent
clause is punctuated as a sentence ("Distributing the work load more evenly."). Often, as
in the parenthetical example, a verbal ("distributing") tries to replace the work of a verb.
Watch out particularly for sentences that begin with relative pronouns (who, which, that)
or subordinating conjunctions (although, because, if, when, while).
2.4.2 Sentence Length: A variety of sentence lengths is appropriate and desirable in
technical report writing. Long sentences are only a problem when they are awkward or
unclear. To be equally shunned are strings of short, choppy sentences, which should
most often be joined together.
2.4.3 Active/Passive: When the subject performs the verb in the sentence it is in the
active voice:
"Medical researchers from Johns Hopkins discovered new gene-splitting techniques last
month." Put in the passive voice, the sentence would show the object, "gene-splitting
techniques," in the subject position: "New gene-splitting techniques were discovered by
medical researchers from Johns Hopkins last month.
Because the passive construction involves the addition of a form of the verb "to be" and
often "by," it becomes more wordy, one reason to avoid it whenever possible. Other
reasons include the confusion of who is doing the action ("The cement should be applied
to both surfaces"), and the greater problem of unraveling meaning in particularly
involved technical explanations. While passive sentences tend to be less direct, they are
not to be avoided entirely; it is when they are overused or used specifically to diminish
authorial presence that they become a problem.
2.5 Parallelism
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Parallel structure is important on the sentence, paragraph, and report level. In a sentence,
it is a means of making form and idea consistent and expresses the equality of ideas.
"The stream runs under the culvert, behind the embankment, and into the pond." In a list
it means to use the same verb tenses, such as in this resume summarizing activities in a
certain job:
1. Created DBase III application system
2. Developed a Logon tracking system
3. Tested software and made recommendations
4. Provided programming support
In each case in the above list, the past tense of the verb is used. In relation to larger
structures--the paragraph and the report itself, parallelism suggests the need to
consistently follow through with forecasted structural cues (for example, using the order
noted in the introduction when discussing a series of items). Finally, headings and subheadings should be parallel (DEAD LOAD ANALYSIS, LIVE LOAD ANALYSIS,
STRUCTURAL ANALYSIS).
2.6 Paragraph Coherence
Paragraph coherence consists of singleness of purpose (unity) established by a core
sentence at the beginning. In addition, one point of view, tense, and attitude is
maintained. Transitional words and phrases also contribute to paragraph coherence, as do
repetition of key words and simple enumeration (first, second, then, next and so on).
2.6.1 Transitions: Transitions create a coherency of ideas between sentences in a
paragraph, and between paragraphs and larger report segments. They help link ideas
together and provide a context for new ideas, giving reports coherence. In the tech
memo, transitions between sentences and sections are both important. For example,
when starting the RECOMMENDATIONS section, use a transition to hook it back up
with previous conclusions: "Because it proved difficult to gather data at larger angles of
deflection, I recommend that the analogue readout be replaced with a digital reading."
Within paragraphs there are many single words that function effectively as transitions and
should be used liberally: "therefore," "consequently," "similarly," "moreover," "besides,"
etc.
2.7 Gobbledygook
Gobbledygook is characterized by its tendency toward the indirect, the vague, and the
pompous. Avoid these hallmarks of gobbledygook: longer variants ("utilize" for "use"),
overly elaborate words ("deciduous perennial, genus Ulmus" for "elm tree"), excess
verbiage ("it is of interest to note that . . ."), and overuse of passive voice. The following
is an example of how an adroit practitioner of gobbledygook might note a lack of milk:
"It has been shown by the present author, on the basis of preliminary evidence that has
not yet been independently replicated by other investigators, that an appropriate quantity
of milk is absent from the refrigerator."
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2.7.1 Nominalizations: A nominalization means adding a weak verb to a noun to replace
a stronger, more direct verb. "The Legal Department will conduct an investigation of the
purchase" can be made more effective by using the strong verb: "The Legal Department
will investigate the purchase." The second form of the sentence is not only more direct, it
is more concise. Nominalizations, while usually used in an attempt to sound formal and
impressive, merely sound affected.
2.8 Mechanics
2.8.1 Capitalization: The following are some of the most common, easy-to-forget rules
on capitalization. Capitalize the names of organizations (The American Society of
Mechanical Engineers) and its internal divisions (Board of Directors). Capitalize first
and last words, as well as all major words, in a memo's subject line ("Analysis of Quality
Assurance Programs"). Also capitalize job titles used with a name (Henry Smith,
Division Manager), chapter titles (Chapter 6) and room numbers (Room 45). See the
dictionary when in doubt.
2.8.2 Colons and Semicolons: The colon is an introducer (These steps should be
followed: fasten seat belt, start motor, and check for traffic.) The semicolon (;) never
functions in this way. It links closely related sentences and helps divide a series using
many commas.
2.8.3 Quotations Marks: Commas and periods always go inside of quotation marks;
colons and semicolons always go outside quotation marks.
3. WRITING PROCESS
The writing process involves a number of steps, and, like your research, each step must be
carefully executed in order to achieve valid results. Five basic steps are often cited and include:
1. Preparation
2. Research
3. Organization
4. Writing a draft
5. Revision
3.1 Preparation
Preparation involves establishing your OBJECTIVE in writing the report, identifying
your READER(S), and determining the SCOPE of the report. In fact, your objective and
scope will be determined by the needs of your readers--what they need to know or do.
Making these judgments requires care and precision. Since the tech memo assignment
asks you to write your opening component (Purpose, Conclusions, Recommendations) to
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a managerial audience, it is imperative that you determine what that audience knows and
needs to know and that you plan carefully how you will communicate technical material
effectively to this non-technical audience.
3.2 Research
For most lab courses research involves experimental activities. Inevitably, the better and
more thoroughly you understand the experimental processes you engage in and the results
you derive, the more coherent and readable your report is likely to be. In terms of report
writing, this step may only involve listing important findings and ideas in preparation for
organizing your report.
3.3 Organization
This step includes deciding on a method of development (see Appendix A), outlining,
choosing graphic aids, and designing the layout (see section A above). Outlining
provides a means of thinking through the report and allows you to create a map to guide
you through your first draft. An outline helps ensure that you have a beginning, middle
and end and that you have given sufficient space to important concepts. It also enables
you to define the hierarchal relationships among ideas. Since you will use arabic
numbers for your reports, it would be helpful to outline in the same manner.
3.4 Writing a Draft
After the careful preparation of an outline, it is best to write a rather quick first draft by
expanding your outline sections into paragraphs. Write without being concerned with
correctness, transitions, or introductions--all of which can be addressed during the
revision stage. At this stage concentrate only on getting your ideas down. FOR THE
TECH MEMO, IT IS ALWAYS BEST TO WRITE THE SECOND, TECHNICAL
COMPONENT, FIRST. Once you have the ideas organized, you can more easily
translate them into the more general idiom suitable for the managerial audience.
3.5 Revision
Revision is the MOST CRUCIAL STEP IN THE WRITING PROCESS. Unfortunately,
this is the step most often slighted by busy students. It is at the revision stage that
readability, coherence, conciseness, and precision make your report an effective and
useful communicator. Always plan to write your first draft early, giving yourself several
days to refine it. Revision is best done in stages. Begin by checking for things like
content, emphasis, point of view, transitions, coherence, and diction. Only at the end
should you worry about spelling and other mechanical areas. Writing the report a little at
a time, in this manner, is not only less painful but helps ensure better results.
4. REPORT SEGMENTS
4.1 Executive Summaries
Because the executive summary is for readers who may not read the entire formal report,
it must provide a comprehensive restatement of the report's purpose, scope, methods,
results, conclusions and recommendations. It should be written for a general audience,
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avoiding technical terminology and reference to figures. Typically, executive summaries
are about 10% of the total length of the report and should be written last.
4.2 Elements of Technical Memorandums
4.2.1 Opening vs. Discussion Components: The distinction between opening and
discussion components in the tech memo is an important one, particularly in terms of
audience. The opening component is for the non-technical managerial audience,
providing an overview of the organizational problem and solution treated in the report
(like an executive summary). It should be written in language that most people can
understand with relative ease. Serving as a summary for decision makers, details of
experimental processes and results are not appropriate and are reserved for the more
technical discussion component. Keep it brief and to the point, though not telegraphic.
Be sure to give yourself plenty of time for this part of the report, since effectively
translating technical data into lay language is a challenging process.
4.2.2 Results vs. Conclusions vs. Recommendations: Be careful not to confuse results,
conclusions and recommendations. The results, which are part of the technical discussion
component, are the complete presentation of your most important test findings, including
relevant numerical details. Your conclusions, on the other hand, which are part of the
less technical opening component, are your summary of the key findings only, with a
brief discussion of their significance. Here you are looking at the bottom line
information, what these results really mean to your readers. Usually, reference to figures
is avoided here (in part because they have not appeared yet). Finally, recommendations
look to future actions. This recommendation might include how you would change the
experiment in some way. In other words, given the results of your experiment and your
conclusions concerning them, what should you or others be concerned with in relation to
the experiment itself or its application to an organization? Be sure the recommendation is
placed within the context of the purpose and conclusions.
4.2.3 Experimental Procedure/Methodology: Methodology entails two parts, describing
both the experimental equipment set up and the steps used in performing the experiment.
Begin by physically describing the equipment (usually with figure) and its function(s)
(CAUSALLY if it has one function, HIERARCHALLY if it has more than one). Next,
sequentially present the steps of the experimental process you followed. While being
concise, remember to use transitions--make this readable as well as informative.
4.2.4 Results: In order to keep your results coherent with the rest of the report, couch
them in the same terms used in your purpose statement. State your results in a decreasing
order of importance (most important to least important). Avoid the random presentation
of findings; use transitions to link and categorize results. Be sure to interpret the figures
you refer to.
4.3 Professionalism
In short, professionalism means that the successful, competent execution of each of the
parts of a report, including format, structure, coherence, technical accuracy, grammar,
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punctuation, neatness, style, etc., is expected. THIS IS BASIC! Remember that you are
not being evaluated on information alone, but on the presentation--THE
COMMUNICATION--of that information. In the workplace, as well as in school, the
overall impression a report gives greatly influences its reception.
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Notes
1. In addition to Handbook of Technical Writing, I drew some ideas and examples from Diana C.
Reep, Technical Writing: Principles, Strategies, and Readings, second edition (Boston: Allyn and
Bacon, 1994), and from George E. Kennedy and Tracy T. Montgomery, Solving Problems through
Technical and Professional Writing (New York: McGraw-Hill, 1993).
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HEAT EXCHANGERS
Ch = mhcph and Cc = mc cpc
Q = mh cph (Th,in - Th,out)
Q = mc cpc (Tc,out - Tc,in)
Q = U A ∆ Tm
( ∆ Ti n - ∆ Tout )
∆ Tm =
1 n ( ∆ Ti n / ∆ Tout )
Cmin = min{Ch, Cc} and Cmax = max{Ch, Cc}
C = Cmin/Cmax
Q
Act ualhea t t ra nsf er ra te
ε=
=
Qm a x M a x i m u m p o s s i b l e h e a t t r a n s f e r r a t e
Qmax = (mcp)min (Th,in - Tc,in)
- Th , o u t )
- Tc , in )
C (T
C (T
ε = h h,in
o r c c,ou t
Cmin ( T h , i n - Tc , i n )
Cmin (T h , i n - Tc , i n )
NTU =
AU
Cm i n
Counter Flow:
ε=
1 - e x p [- N T U (1 - C ) ]
1 - C e x p [- N T U (1 - C ) ]
Parallel Flow:
1 - e x p [- N T U (1 + C ) ]
1+ C
Plate Heat Exchangers
A = (Np - 2) Ap
(Np = Number of plates;
Ap = Area of each plate)
1 1
t
1
=
+
+
U hh
kp
hc
hh = heat transfer coefficient on the hot side in Btu/hr/ft2/F
hc = heat transfer coefficient on the cold side in Btu/hr/ft2/F
t = thickness of the plate in ft
kp = thermal conductivity of the plate in Btu/hr/ft/F
Uε - N T U = C F U
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