MIT Guide to Science and Engineering Communication 2ed - J Paradis (MIT 2002) Episode 13 pps

The criteria for restarting FacilityXYZ have not been met for the water drain capacity of the filtercompartment, the stability of the charcoal in the absorber, and thecapacity of the abso

Although it took eight more words to write this second version, itsthree sentences develop the information with greater clarity.]

3 Make choppy writing flow Choppy sentences interrupt the smoothflow of thought, and they can be repetitious Combine overly short sen-tences with the help of transitional words, coordinating conjunctions(e.g., and, yet, but, nor, or), and subordinating conjunctions (e.g., unless,since, because, if, when)

Choppy writing

Cytolytic toxins act directly on cell membranes They disturb thenormal physiology of the target cell They ultimately kill the cell.Cytolytic toxins are not a single group of related chemicals They arenot produced by one class of organism These toxins are heterogeneous

in their chemical structures They can be obtained from plant andanimal sources They do not share a common mechanism of action.There are several ways for cytolytic toxins to interfere with the normalpermeability barrier formed by the cell membrane See Table 1.Improved

Cytolytic toxins act directly on cell membranes by disturbing thenormal physiology of the target cell and [Coord Conj.] ultimatelykilling it These toxins are not a single group of related chemicalsproduced by one class of organism Rather [transitional word], theyare very heterogeneous in their chemical structures and [Coord.Conj.] can be obtained from both plant and animal sources

Consequently [transitional word], cytolytic toxins do not share acommon mechanism of action, but [Coord Conj.] have several ways,

as summarized in Table 1, of interfering with the normal permeabilitybarrier of the cell membrane

4 Use parallel subject headings to reveal logical flow Technical ject matter sometimes is so dense with terminology and operations thateven well-designed paragraphs are difficult to follow The reader muststruggle to work out the natural hierarchy of ideas Subject headingsoften help by marking out topical patterns of subordination and paral-lelism in otherwise opaque prose In the example below, the revised ver-sion communicates at a glimpse the essential logic, and this explicitstructure in turn enables the reader to get information out of the para-graph more effectively

sub-Dense prose

3.4 Unresolved Issue Number 4 The criteria for restarting FacilityXYZ have not been met for the water drain capacity of the filtercompartment, the stability of the charcoal in the absorber, and thecapacity of the absorber

The above unresolved issue consists of three separate restart criteria.The details of these criteria are as follows The first criterion is thatfilter compartment water drains shall be demonstrated to be capable

of meeting their design function The second criterion is that thepossible iodine desorption and autoignition that may result fromradioactivity-induced heat in the carbon beds shall be considered whendetermining the adequacy of the charcoal absorbers Finally, the thirdcriterion is that the absorber section of the XYZ facility shall containimpregnated activated carbon filters demonstrated to remove gaseousiodine from influent The carbon filters must have an average atmosphereresidence time of 0.25 seconds per 2 inches of absorbent bed Themaximum loading capacity The capacity of the water drains (thefirst criterion) is addressed in RRD-RSE-910003, ‘‘Revi-sion to FilterCompartment Drain Capacity’’ (21 January 1991)

Revised version, with headings showing subordination and parallelism3.4 Unresolved Issue Number 4

The criteria for restarting Facility XYZ have not been met for thewater drain capacity of the filter compartment, the stability of thecharcoal in the absorber, and the capacity of the absorber

3.4.1 Criteria for Restarting

The following criteria must be met before Facility XYZ may resumeoperations:

3.4.1.1 Capacity of filter compartment drain lines The filtercompartment water drains must be demonstrated to be largeenough to handle the capacity called for in the design

3.4.1.2 Stability of the absorber’s charcoal bed The absorber’scharcoal bed must be shown to be stable enough to prevent anypossible iodine desorption and the autoignition that might resultfrom radioactivity-induced heat in the carbon beds

3.4.1.3 Use of the carbon filters in the absorber section Theabsorber section shall use impregnated activated carbon

demonstrated to remove

3.4.2 Assessments and Conclusions

The above criteria may be met as follows:

3.4.2.1 Capacity of the filter compartment drain lines

Guidelines for regulating the capacity of the water drains areaddressed in ‘‘Revision to Filter Compartment Drain Capacity’’(RRD-RSE-910003, 21 Jan 1991)

5 Emphasize the active voice Although the passive voice has manylegitimate uses, overusing it can lead to indirect, wordy prose The pas-sive voice inverts the straight agent-action-thing acted upon (i.e., subject-verb-direct object) sequence of the sentence The thing acted uponbecomes the subject of the sentence For example, Enzymes break downproteins becomes Proteins are broken down by enzymes Both sentencesare grammatically correct, but the active verb break down is more directand simple than the passive verb is broken down The word order of thedirect sentence is easier to process

Passive/indirect writing

Different types of protein are broken down by different enzymes, andstarch is dismantled by still other enzymes into its constituent sugarmolecules

Active/direct writing

Different enzymes break down different types of protein, and stillother enzymes dismantle starch into its constituent sugar molecules.The question of using the passive voice is often a matter of emphasis.The writer of the sentence above who is discussing proteins and wants tokeep protein as the subject will choose the passive form The writer whowants to maintain sentence focus on enzymes will choose the activeform, which makes enzymes the subject

Here are some instances in which the passive voice leads to awkward,wordy, or ambiguous expressions:

Wordy writing

The cooling of the thermal unit is accomplished by using electric fanswhich are run every other hour during the day [The ‘‘empty’’ verbsaccomplish and run may be eliminated without loss of meaning.]Improved

The thermal unit is cooled with electric fans every other hour duringthe day

Wordy writing

An increase in water volume would have the effect of reducing thestability of the slope along the North wall of the power plant [ .have the effect of contributes nothing to the sentence meaning.]Improved

Increased water volume would reduce slope stability along the powerplant’s North wall

Wordy writing

There was a secondary stress that was identified with the stresscaused by constrained thermal expansion of the pipe fitting [Avoid

empty clauses like there is or there was at the start of sentences Notealso the repetitious use of stress.]

due to the fact that because

has the capacity to can

it should be noted that note that

has been conducting an analysis of has been analyzingWordiness sometimes originates in words and phrases that repeatwhat has already been stated or implied in the sentence Compound for-mations (nouns, verbs, adverbs, and adjectives), for example, are a com-mon source of repetition

Repetitious verbs

Ring currents were observed and demonstrated to play a role infullerene magnetism

[Improved: were demonstrated to play ]

Repetitious sentence complements

Mouse and human receptors are so different and distinct that [Improved are so different that ]

Repetitious ideas

The main cost of the hydro unit is determined by the costs of thecatalyst and the frequency of its replacement Catalyst life also is themajor factor on the overall economics of operating the hydro unit.[Both sentences are noting that replacing the catalyst is the mainoperating cost of the unit in question.]

Catalyst life largely determines the economics of the hydro unit,because its main cost is catalyst replacement

Redundant words

was a close approximation to [ was similar to ]

with absolute certainty [ with certainty ]

was blue in color [ was blue ]

round in shape [ round ]

7 Avoid the abstract prose caused by excessive nominalizing nalizing means forming nouns from verbs You take a verb like detect,change it to an abstract noun like detection, and add a passive general-purpose verb like has been achieved From these changes you can get asentence like the following:

Nomi-Wordy nominalization

The detection [Abstract noun made from verb to detect] of intracellularproducts of polymerase chain reactions has been achieved [Passivegeneral-purpose verb] by two very different methods

This example may be simplified by restoring the main action, detect, tothe verb position of the sentence:

Improved

Intracellular products of polymerase chain reactions have beendetected by two very different methods [The main action has beenrestored to the verb.]

Alternate improvement

We have detected intracellular products of polymerase chain reactions

by two very different methods [By restoring the first-person agent,

we get an active verb.]

Technical prose uses a lot of nouns like detection as a way of focusing

on abstract concepts or processes Yet, nominalized words can produceawkward, wordy writing, with lots of abstract nouns supported by emptygeneral-purpose verbs Here is another example:

Wordy nominalization

Measurement of the levels of about 6,800 different genes in bonemarrow samples was carried out on 38 leukemia patients

ele-Microscopic mechanical systems (MEMS) can respond to a variety ofinputs, including light, heat, and vibrating objects that cause

stimulations [The end series of the sentence includes two nouns, lightand heat, followed by a clause.]

Improved

Microscopic mechanical systems (MEMS) can respond to a variety ofinputs, including light, heat, and vibrations

Faulty parallelism in larger sentence elements

The negative Doppler effect increases both because of the increasingfraction of resonance absorber [phrase] and the neutron energyspectrum is lowered [clause] [A phrase is mismatched with a clause.]Improved

The negative Doppler effect increases both because the fraction ofresonance absorber is increased and the neutron energy spectrum islowered [Two clauses balance the sentence.]

Faulty parallelism also develops in incomplete constructions

Faulty parallelism from an incomplete construction

Zinc exerts a greater effect on the vulcanization of isoprene rubbersthan synthetic rubbers such as SBR and BR [The sentence is

comparing zinc to synthetic rubbers The author intended to comparezinc’s effect on isoprene rubbers with its effect on synthetic rubbers.]Improved

Zinc exerts a greater effect on the vulcanization of isoprene rubbersthan it does on the vulcanization of synthetic rubbers such as SBR

and BR [The construction setup in the first part of the sentence hasbeen completed.]

Sentence parallelism also helps keep ideas clear The sentence below isgrammatically correct, but the two clauses arrange the parallel items invery different ways The result is hard to read:

Faulty parallelism in ideas

Under a centrifugal stress exceeding 5000 psig, the test alloy fracturedalong the weld seam of surface A; the rupture along the horizontalaxis of Surface H of the alloy occurred under a hydrostatic pressurethat exceeded 10,000 psig [The subjects and verbs of the two

independent clauses do not contain parallel information The subject

of the first half of the sentence is alloy; the subject of the second half

of the sentence is rupture.]

Improved

Under a centrifugal stress exceeding 5000 psig, the test alloy fracturedalong the weld seam of Surface A; under a hydrostatic pressureexceeding 10,000 psig, the alloy ruptured along the horizontal axis ofSurface H [The two subjects and verbs contain parallel information,which makes the improved version easier to follow.]

9 Don’t line up long strings of modifiers in front of nouns Scienceand technical prose depends heavily on modification for achieving itsaccuracy In an effort to be accurate, writers often stack up modifiers infront of the main noun The true effect of these modifier ‘‘stacks,’’ how-ever, is not accuracy but ambiguity The reader has to work out whichwords are modifying other words in the stack For example, in ‘‘under-ground plant effluent soil contamination,’’ the adjective undergroundcould be modifying either plant or contamination The phrase could bereferring either to ‘‘contamination from an underground plant’’ or to

‘‘underground contamination from an above-ground plant.’’ To resolvethis ambiguity, we put some of the modifying information after the mainnoun: ‘‘underground soil contamination by a plant effluent.’’ Here aresome additional examples of stacked modifiers:

Stacked modifier

Large low-cost central receiver electricity generating power plantscould significantly alter local desert climates by modifying their

radiation balances [The main subject, plants, is modified by 8

preceding words Do the adjectives large and low-cost, for example,apply to receiver or to plants?]

A contributing cause of the accident was the poor communicationamong the personnel of the health protection group, the

environmental safety group, and operations management [3 groups]Alternate improvement

A contributing cause of the accident was the poor communicationbetween the personnel of the health protection and environmentalsafety group and operations management [2 groups]

Stacked modifiers are common in technical titles

Stacked modifier in a technical title

An Interdisciplinary Study of Coupled Atmosphere-Ocean ModelCirculation Flux Adjustments [What is being modeled?]

Improved

An Interdisciplinary Study of Flux Adjustments in Circulation Models

of Coupled Atmosphere-Ocean Systems

be-Don’t put modifying words and phrases into out-of-the-way places in thesentence.

Misplaced modifying phrase

The storage drums showed signs of deterioration that could be seenunder severe corrosion [The phrase under severe corrosion appears

to be modifying seen rather than drums.]

‘‘Walking down the street, the tall buildings came into view,’’ the writer

is suggesting that the tall buildings are out for a walk Although we canusually understand what a dangling modifier is trying to modify, dan-glers are errors of logic

Dangling modifier

By carefully adjusting the reflecting surface spacing, the desiredtransmission wavelength can be isolated [The action of adjusting thespacing is misattributed to wavelength, which is the subject of themain clause.]

11 Make your pronouns refer clearly to the objects and ideas that theystand for Pronouns (e.g., he, she, it, they, this) refer back to a preced-ing noun (i.e., the referent) They help tie the different sections of thesentence or paragraph together without repetitiously mentioning thenoun It is easy, however, for a writer to think his or her pronoun is re-ferring to something definite when, in fact, the referent is unclear

Vague pronoun reference

Although the photosynthetic bacteria all possess structural bodieswith localized photochemical apparatuses, their morphologies varyfrom species to species [Does their refer to apparatuses, elements, orbacteria?]

Improved

Although the photosynthetic bacteria all possess structural bodieswith localized photochemical apparatuses, the morphologies of theirstructural bodies vary from species to species

A vague pronoun reference often forms when a pronoun that refers to anoun in the previous sentence appears alone as the subject of the nextsentence

Vague pronoun reference at the start of a new sentence

One of the distinctive features of Mars’ southern hemisphere, thegiant Hellas impact basin, is thought to have been formed from anasteroid hit It is surrounded by a ring of ejected material that is morethan a mile thick and reaches 2.500 miles from its center [It and itscould refer back to several nouns, including features, hemisphere,basin or hit.]

Improved

One of the distinctive feature of Mars’ southern hemisphere, the giantHellas impact basin, is thought to have been formed from an asteroidhit The basin is surrounded by a ring of ejected material that is morethan a mile thick and reaches 2,500 miles from the basin center [Thepronoun has been replaced with the noun that was its intendedreferent.]

12 Make words related by number, pronoun reference, and case agreewith each other A plural subject requires a plural verb (subject-verbagreement), a plural noun-referent requires a plural pronoun (pronoun-referent agreement), and a pronoun must agree with the case (case agree-ment) in which it is used

Subject-verb nonagreement

The mixture of methanol and water used in the process were thenrecovered and distilled for further recycling [The subject is mixture,which is singular and takes a singular verb.]

sen-Each of the casings are constructed from 9 percent nickel steel,because they must withstand constant temperatures as low as

320
F [Each, the subject of the sentence, is singular and requires asingular verb, is constructed The second pronoun, they, also does notagree with its referent, each.]

Improved

The casings are constructed from 9 percent nickel steel, because theymust withstand constant temperatures as low as320
F [The twopronouns are made into plurals.]

Nonagreement in pronoun case is less common in the writing of scienceand engineering than it is in college themes, but it does occasionallyhappen

Pronoun case nonagreement

The responsibilities of laboratory management have been shifted toRoberts and I [The pronoun is the object of the preposition to andshould be in the objective case: me.]

Improved

shifted to Roberts and me