1. Which part of your paper should you create first?

1
1. Which part of your paper should you create
first?

• Graphical Results

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2. What type of Excel plot should you make if you
are looking at the relationship between 2
continuous variables?

• Scatterplot

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3. What type of statistical analysis would you
carry out?

• Regression

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4. What do you put in the figure text?
Figure 1. Nine lakes in Wisconsins Northern
Highland Lake District in late September/early
October, 2006. Chlorophyll a concentrations are
averages of a surface measurement and a deeper
measurement for each lake. The regression is
significant (pcalc 0.045)
How many, Where, When, What, Significant?
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5. What about data grouped into categories?

• Graph points or bars with error bars
• Stats ANOVA or t-test

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6. Figure text
Figure 2. 20 lakes in Wisconsins Northern
Highland Lake District in late September/ early
October, 2006. Lower lake orders correspond to
higher landscape positions. Silica concentrations
for each lake are from the middle of the
epilimnion or half the Secchi depth for mixed
lakes. Groups that share a letter are not
significantly different (t-test, pcalc gt 0.05).
Error bars are /- two standard errors.
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7. How should you start your written results?

• Summary Statistics tell us about your data
• IN GENERAL

Means and ranges Surface total phosphorus
concentrations ranged from 0 to 0.076 mg / L with
and average of 0.024 mg / L.
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8. What else do you do in your written results
section?

1. Refer to figures
2. Describe what they show (beyond the obvious)
3. Are trends significant?

Figure 1 shows the slight positive relationship
between surface total phosphorus concentrations
and surface chlorophyll a concentrations. The
relationship is not significant (pcalc 0.75)
and note two major outliers Crystal Bog in the
upper left and Diamond Lake in the lower right. A
regression without these two points increases the
slope slightly to 0.0023 but does not yield a
significant result (pcalc 0.6).
HINT Vary your sentence structure to avoid
sounding like a laundry list.
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9. After results, what next?

• Methods

What are the three types of methods you need to
summarize?

• FIELD
• LAB
• STATISTICAL

HINT Only include methods relevant to the data
you used!!!
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10.How might you start describing your field
methods?

• Basic description of your system
• We sampled 20 lakes in Wisconsins Northern
  Highland Lake District for 10 were sampled on
  September 30, 2006 and 10 were sampled on October
  1, 2006. All of these lakes are generally
  considered oligotrophic. Maximum depth ranged
  from . . . Average surface area ranged from ..

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11. Bad idea for field and lab methods

• A long-winded, cookbook, with irrelevant
  detail
• Back in the lab we used a pipette to measure out
  10ml of sample into an acid washed test tube and
  then used another pipette to add 0.1ml of
  concentrated hydrochloric acid. Then, several
  weeks later we added 1.5ml of 5 sodium
  persulfate . . . .
• AND ON AND ON AND ON

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12. What to Include for Field Methods?

• When
• Where
• Basic description of system
• Type of equipment (12.1L Schindler trap, Van Dorn
  sampler)
• What depths you sampled and why?
• A lake was considered stratified if . .
  . If a lake was stratified, we sampled WHERE in
  the epilimnion . . .If a lake was not stratified,
  our epilimnetic equivalent was WHAT the Secchi
  depth . . .

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13. What do you include for lab methods?

• How you preserved/maintained integrity of your
  samples (acid, refridgeration, freezing)
• General type of analysis (fluorometry,
  spectrophotometry, titration)
• Cite lab manual for more details

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14. Bad idea from before Back in the lab we
used a pipette to measure out 10ml of sample into
an acid washed test tube and then used another
pipette to add 0.1ml of concentrated hydrochloric
acid. Then, several weeks later we added 1.5ml of
5 sodium persulfate . . . . BLAH, BLAH, BLAH,
BLAH, BLAHBLAH, BLAH, BLAH, BLAH. . . . . . . .
. . . . . . . . . . . . . .. . .

• 15. Good idea
• Total phosphorus samples were preserved with
  concentrated hydrochloric acid and analyzed using
  standard spectrophotometric methods (Arnott et
  al. 2006).

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15. What do you say about your statistical
methods?

• Type of analysis, what data you used, and why
• ANOVA was used to compare surface chlorophyll a
  concentrations among categories of landscape
  position. Surface concentrations were used
  because samples from deeper depths may have been
  out of the photic zone and/or in the nutrient
  rich metalimnionfactors that could have
  confounded any relationship between chlorophyll a
  and landscape position
• P values
• Calculated p-values less than or equal to 0.05
  were considered significant.
• Software
• All statistical analyses and graphs were
  generated using Microsoft Excel.

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16. What do you include in your Introduction?

• Background/Rationale (CITE LIT)
• Phosphorus is often the limiting nutrient for
  phytoplankton in lakes world wide (Kalff 2002).
• Your hypotheses
• I hypothesize that total phosphorus
  concentrations and chlorophyll a concentrations
  will be positively correlated in 20 northern
  Wisconsin lakes.

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17. Bad idea for your introduction

• Vague Generalities
• The purpose of this paper is to study x,y,z.
• Phosphorus is an important nutrient in lake
  ecosystems.
• In this paper, I examine data gathered on the
  Trout Lake field trip

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18. Another Bad Intro Mistake

• Spending too much time explaining why we should
  care or on tangential background material.
• A paragraph on the negative aspects of
  anthropogenic eutrophication is TOO MUCH.

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19. A good intro . . .

• Clearly lays out the rational for all your
  hypotheses and integrates literature in doing so.
• Explicitly states your hypotheses and tells the
  reader in what system these hypotheses will be
  tested
• Flows nicely (vary your sentence structure!!)
• DOES NOT sound like a laundry list
• DOES NOT ramble or integrate information that is
  only tangential to your hypotheses or the system
  at hand.

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20. Citing Literature

• What is required?
• Enough to sound knowledgeable
• 3 new sources at a minimum (not including lab
  manual, 2 papers you have already read, non-peer
  reviewed sources)
• Must have a minimum of one new paper
• Can use textbooks or specialized books
• Where does it belong?
• Intro, methods, discussion