Formal Laboratory Reports

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Formal Laboratory Reports

• You can write a GREAT one!

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There are 7 pages (parts) in a formal lab report
1- TITLE PAGE 2- HYPOTHESIS PAGE 3- RESEARCH
PAGE 4- MATERIALS LIST 5- PROCEDURE 6- DATA 7-
CONCLUSIONS
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TITLE PAGE

• The title of the experiment should be centered
  across the top of the page using title format
• Title should be descriptive of the experiment
  not cute
• Your full name, date and period should be near
  the bottom centered or justified right
• An appropriate graphic

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Example
An Investigation of the Time Required for a
Deceased Rabbit to Naturally Decompose.
Jennifer A. Douglass August 23, 2007 4th Period
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Hypothesis

• According to the Article Decomposition in the
  Natural Habitat (Journal of Decay, Sept. 2004, pg
  86, James Funk) organic materials break down at
  about the same rate regardless of the size of the
  specimen. Organic material decays at the average
  rate of 50 grams/24 hour period. That means that
  an elephant will decay at the same rate as a
  rabbit. The elephant will, however, take more
  time to decompose completely because it is
  larger.
• Therefore, using the above information as a
  guide, it is my hypothesis that a rabbit will
  decompose at the average rate of 50 grams/day
  since rabbits are composed entirely of organic
  material.

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Materials list

• Pencil or pen
• Paper
• 1 1000 gram Rabbit (Rabbiti domesticus)
• Morgue chamber
• 500ml ether
• Mesh Rabbit Cage 50cm x 50cm x 25cm
• Balance
• Shovel
• Note the materials list is an all inclusive
  list of EVERYTHING used to perform the experiment
  including sizes in the order that you use
  them

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Procedure

• 1- Euthanize rabbit in morgue chamber using
  ether. Follow directions included with the
  morgue chamber
• 2- Place the euthanized rabbit carcass in the
  cage.
• 3-Mass the rabbit and cage record mass and date
  on data table
• Locate the cage in an area not accessible to
  scavengers.
• Re-mass the cage and rabbit each day and record
  the change in mass

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Data
Mass of cage and rabbit (g)c day beginning 8/10
1700 g
1675 g 1- 8/11 mass lost -25g
1627 g 2- 8/12 mass lost 48g
1555 g 3- 8/13 mass lost - 72g
1507 g 4- 8/14 mass lost - 48g
1480 g 5- 8/15 mass lost 27g
1402 g 6- 8/16 mass lost 72g
1347 g 7- 8/17 mass lost 55 g
1215 g 8- 8/18 mass lost 132g
1078 g 11- 8/19 mass lost 137g
923 g 12- 8/20 mass lost 155g
707 g 13 8/21 mass lost 216g

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Data continued

• 8/10 total mass of rabbit and cage recorded
• 8/11 mass rabbit and cage no sign of
  decomposition mass loss is possibly due to
  dehydration
• 8/12 mass rabbit and cage many flying insects
  present. These were removed before massing.

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Data continued

• 8/13 massed rabbit and cage. Carcass is
  beginning to drip liquid
• 8/14 massed rabbit and cage maggots are
  apparent in some of the soft tissue these were
  not removed before massing carcass has
  developed a slight odor or rotting meat.
• 8/15 massed rabbit and cage odor is stronger
  than before the carcass is more drippy than in
  previous days

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• Continue with the log book until the experiment
  is complete

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Graph of data
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HINT making your graph on EXCELL will make you
life easier!

• More than one graph may be necessary in this
  case one will do

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Conclusions

• Did the data support or refute the hypothesis and
  WHY..
• Does the hypothesis need to be adjusted?
• What is the next logical step in the experimental
  process?
• Suggestions for further research

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Conclusions

• As expected the rabbit and cage did lose mass
  over time.
• However the average mass lost per day was greater
  than expected 76.38g/day
• The total mass lost was 993g. There were tiny
  bits of rabbit matter stuck to the bottom of the
  cage at the end of the experiment. This is why
  the entire 1000g of rabbit mass are unaccounted
  for.

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Conclusions Continued

• Possible explanations for the greater than
  expected results
• 1- The rabbit was not in contact with the
  ground. Therefore liquids were able to drip from
  the body as opposed to seep into the ground as
  would happen in a natural setting.
• 2- Although temperature was not sited as a
  variable in the original article, it is possible
  that the warm temperatures in Georgia encourage
  bacteria and fungus growth at a greater rate than
  in the location of the original experiment.

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Further studies

• In the future I would like to compare the
  decomposition rates of carnivores vs.
  herbivores. It is possible that because their
  herbaceous diet is rich in water the bodies or
  herbivores have a high percent of mass in water.
  This could affect decomposition rates.