Transcript Crash Course on Lab Write-ups

CRASH COURSE ON LAB
WRITE-UPS
FORMAT
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All lab reports are to follow this format: (make sure the content after the (:) is block
justified.
Title:
Problem/Research ?:
Hypothesis:
Theory:
Variables:
Materials:
Methods:
Data:
Data Analysis:
Diagrams:
Conclusion & Evaluation:
TITLE
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Descriptive: Use active verbs
Examples:
Not Good
1.
Ascorbic Acid vs. Juices
2.
Ascorbic Acid in different types of Juices
3.
The Investigation of Ascorbic Acid in Differing Types
of Juices
Good
1.
The Investigation of Ascorbic Acid Concentration in
Differing Types of Fruit Juices
PROBLEM / RESEARCH ?
Use the title and continue the active verb
 Include the variable tested
 Your problem has to be testable
 Should not have a yes or no answer
Good Example:
In this experiment we will investigate the amount of vitamin C (ascorbic acid) in
different fruit juices by titration of the juice with a solution of DCIP. AA. is an
important compound b/c… Humans cannot manufacture…. Therefore they must
ingest… To make an informed decision…We ask the quest. “Does a citrus based
juice contain more or less vitamin C than a non citrus based juice?”
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Bad:
“Does a citrus juice contain better vitamin C than a non citrus based juice?”
“Will drinking orange juice be better for you than drinking apple juice?
HYPOTHESIS
If…(assumption), then when we… (method), we will see (expected
outcome), because (background knowledge)
Example:
1.
If higher amounts of AA are found in citrus drinks vs non citrus drinks, then
when we titrate orange juice and apple juice, we will see it takes less
drops of orange juice to neutralize DCIP because….
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If enzyme activity is related to temperature (or pH or quantity), then
when we increase the temperature we will see an increase in the products
of an enzymatic reaction because…
If diffusion efficiency is related to the ratio of surface area to volume,
then when we decrease the SA/V (increasing volume of a cell mass), we
will see a decrease in the rate of diffusion into a cellular mass (potato)
because...
THEORY
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Background research
Write what you know
VARIABLES
Dependent variable: what will change b/c of IV
 Independent variable: the factor you control and change
 Control Variables: what stays constant so they have no
effect on the experiment
 Experimental Control “standard of comparison”
 IN YOUR LAB REPORT:
Use the same color print as above (red, blue, green) for
each of the variables in your lab and then list the
variables in black.
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MATERIALS
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Numbered list
Indicate amounts:
Examples:
- 0.25mg/l of DCIP
- 5-graduated cylinders (10ml)
- 5 beakers
METHODS
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You should be able to hand it to mom and dad and
they should be able to do exactly what you did
Always include…”repeat experiment with X# trials”
Include diagrams regarding the procedures
DATA
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Descriptive titles (includes variables)
Appropriate units
Descriptive headings for variables
Keep in mind significant figures:
- Sig figs
- neatness – use a ruler if done by hand
DATA ANALYSIS
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Graphs
Descriptive title
Units and labels axis
key
Add a brief description of what the graph is about
(think of a caption in the textbook)
Calculations
Calculated errors
CONCLUSION AND EVALUATION
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This is an area which gives many students trouble. It requires
looking at the experimental title, the purpose, the data and
calculation sections of the lab report and bringing them all
together. Sometimes it involves the comparison of the student's
experimentally derived answer to a known literature value.
A. Use your data (#’s) to explain whether your
results support your hypothesis. Discuss trends.
B. Start with the evaluation of your procedure.
Systemic errors:
Random errors:
C. Discuss improvements