Written ReportsSuggestions

for Good Scientific Writing

John E. SilviusProfessor of BiologyCedarville University

Written ReportsSuggestions

for Good Scientific Writing

Part I

General Suggestions

Written ReportsSuggestions for Good Scientific Writing

1. You may use first person plural (e.g. We estimated plant cover by using a …) or passive voice (e.g. Plant cover was estimated by …) 2. Place the subject of each sentence as early as possible in the sentence. Poor: “In order to determine plant height diversity, we measured …” Better: “Plant height diversity was based upon 3 Robel pole measurements…” 3. Make two concise sentences rather than a long string of clauses. 4. Be precise so that the reader could repeat your “Methods” and obtain your materials and instruments from your wording or via citation of Lab Manual.

Writing METHODS – A Few Suggestions

Cedarville U. Prairie RestorationRank-Abundance: August, 2001 and Sept., 2002

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Abundance Rank (Top 28 Species)

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Figure 1

2001

2002

Figure 1. Rank-abundance curves for plant species of the Cedarville University Prairie Restoration, based on quadrat sampling during two different summers. A slightly greater species evenness was evident among the ten most abundant species in 2001 compared to 2002. Such comparisons, however, must consider the larger sample size in 2001. The 52 quadrat samples in 2001 expressed a more accurate estimate of species richness than the 19 samples in 2002.

What’s in this figure?

Where?

Method?

Brief interpretationor save detail for

“Results” if instructed.

Writing a Figure Legend

Cedarville University Prairie RestorationRank-Abundance Curves for Two Consecutive Years

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Figure 1. Rank-abundance curves for plant species of the Cedarville University Prairie Restoration, based on quadrat sampling during two different summers. A slightly greater species evenness was evident in 2001 compared to 2002. Such comparisons, however, must consider the larger sample size in 2001 (52 quadrat samples) as compared to 2002 (19 samples).

Preparing Figures:Read the “bubbles” to understand the intent: Chart title explains

subject under investigation and its

location and time frame. Axes labels

give parameters.

Legend repeats chart title (what-where-when), and cites “Methods” (how)…

…and, notes any cautions.

…then, helps reader interpret

the data...

Suggestions for Good Scientific Writing

Suggestions for Good Scientific Writing

Preparing Figures: Some ExamplesRead the “bubbles” to understand the intent: Chart title explains

subject under investigation. Axes labels give

parameters.

Legend repeats chart title (what-where-when), and

refers to “Methods” (how)…

…then, helps reader interpret

the data...

Suggestions for Good Scientific Writing

Preparing Figures: Some ExamplesRead the “bubbles” to understand the intent:

Legend states the“what-where-when”

…then, helps reader interpret

the data...

Written ReportsSuggestions for Good Scientific Writing

SENTENCE A:“Table 2 shows that the most dominant plant species are Indian Grass and Tall Goldenrod.”

SENTENCE B:“The most dominant plant species of the prairie restoration site based upon random plot sampling are Indian Grass and Tall Goldenrod (Table 2).”

Which of the following sentences states the experimental results best?

Writing RESULTS or DISCUSSION:

SENTENCE A:“Table 2 shows that the most dominant plant species are Indian Grass and Tall Goldenrod.”

Concise Scientific WritingSuggestions for Good Scientific Writing

You need not “show” the reader the data.

See reference to “(Table 2)” in SENTENCE B.

But how is this judged?Include reference to

method used to determine (see Sentence

B.

“Table 2” above makes

a poor subject. See SENTENCE B.

RESULTS -- critique of SENTENCE A:

SENTENCE B:“The most dominant plant species based upon random plot sampling are Indian Grass and Tall Goldenrod (Table 2).”

But how are “dominants” judged?Include reference to

method used to determine (see Sentence

B.)

Written ReportsSuggestions

for Good Scientific Writing

Part II

Using Statistics in Your

Results and Discussion

Written ReportsSuggestions for Good Scientific Writing

SENTENCE A:“Figure 1 shows that plants grown under high light intensity had longer stem internodes as shown by our t-value of 2.81 which was significant p < 0.05 for 12 degrees of freedom.”

SENTENCE B:“Increased light intensity caused significantly greater internode elongation in radish plants (p < 0.05) (Figure 1).”

Which of the following sentences states the RESULTS best?

Writing RESULTS – Referring to Statistical Testing

Concise Scientific WritingSuggestions for Good Scientific Writing

SENTENCE A:“Figure 1 shows that plants grown under high light intensity had longer stem internodes as shown by our t-value of 2.81 which was significant at the 95% level for 12 degrees of freedom.”

SENTENCE B:“Increased light intensity caused significantly greater internode elongation in radish plants (p < 0.05) (Figure 1).”

You need not “show” the reader

the data. See “(Figure 1)” in SENTENCE B.

The t-value itself is not significant. Rather it may indicate that the

difference between two means is significant.

You need not go into this detail in RESULTS if you have explained what statistical test you used

in METHODS.

Your variable (light

intensity) should be the subject. See SENTENCE B

RESULTS -- critique of SENTENCE A:

SENTENCE B:“Increased light intensity caused significantly greater internode elongation in radish plants (p < 0.05) (Figure 1).”

Concise Scientific WritingSuggestions for Good Scientific Writing

SENTENCE A:“Figure 1 shows that plants grown under high light intensity had longer stem internodes as shown by our t-value of 2.81 which was significant at the 95% level for 12 degrees of freedom.”

Here is a critique of two sentences which refer to statistical probability.

Low probability supports your claim of “significantly greater” meaning that you can reject Ho with < 5% chance of Type I error. “Methods” will note that you used t-test.

The “significantly greater” indicates that you have based your claim on statistical tests

(see blue bubble below).

Reader encounters subject first

Reader will know where

to find data by this brief reference.

Exhibit A: The probability suggests that disturbance does not enhance species richness (p > 0.10; Table 2).

Poor subject Good (biology) subject

Exhibit B: The null hypothesis for species richness per sample shouldnot be rejected. What was treatment in question?

“Statistics subject” “biology is object of prep.”

Exhibit C: According to the calculated “p” value (p > 0.10), soil disturbance does not have an effect on species richness because there is more than a 10% chance that our null hypothesis

would be correct.

Can you fix this one? Mid-summer mowing did not affect species richness (p > 0.10).

Omit so “bio subject” is up front

● ●♦(

Table 2. [Enter descriptive legend here when table is complete]Parameter Control Disturbed

Total Sample Points (n) 15 36Statistical Analysis of Response Variable Means:

Control Disturbed df t-value pSpecies Richness per Sample 10.8 12.5 49 1.53 > 0.10

Mean Cover

Additional Parametersof your choice