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For years scientists have used the scientific method to expand their horizons. They observe something, make a hypothesis about why it occurs, perform an experiment on it, and form conclusions. They learn by doing this and share their knowledge with other scientists. It is important that anyone performing an experiment write it down so that any other scientist can perform the same experiment and form the same conclusions. And, just like in everything else, there is a right way to write a lab and a wrong way. The right way includes five easy steps. Next time you write a lab, try using this form:

Problem: State the problem you are trying to solve. Include what you already know and what you need to find out.

Materials: Write down all the tools and materials you will need, including their measurements. Make this as accurate as possible so it can be repeated. Include even the small things, such as water.

Procedure: Now explain each step of the process. Include details and be as accurate as possible. Indicate how another scientist is to record their data.

Data/Observations: Compile only the information that is relevant. Put it in an easy-to-read format - tables are always nice.

Conclusions: Here is your chance to express your opinion about the lab, where there might be mistakes or miscalculations, and most importantly the solutions to your original problem. This section is the place to be opinionated - everywhere elts in the lab (exept for hypothesis) should be purely fact.

Sample Lab Report

Problem: Through Probability, predict the outcome of certain events, namely genetics problems. We already know some of the laws of probability. This will help us out.

Materials: 2 coins, masking tape, scissors.


A. On a seperate sheet of paper, copy the chart shown below.

B. Work with a partner. You will toss tow coins at the same time. Your parnter will tally the results - heads/heads, heads/tails, or tails/tails. First toss both coins 10 times and record your results. Then toss both coins 50 times and record the results in chart 1.

C. Determine the ratio of heads/heads to heads/tails for each series of tosses.

D. Cut off 4 peices of tape just big enough to fit on the coins. Stick the tape on both sides. Write T on one side and t on the other side. Consider that these represent traits in pea plants; T stands for tall pea plants; t stands for short pea plants. Tossing two coins together represents the crossing of hybrid pea plants as in Mendel's F1 cross.

E. Work with a partner. Toss the two labeled coins together 10 times, 50 times, and 100 times. On a separate sheet of paper, copy the chart below and record your results.

F. From Mendel's experiments with pea plants, you know that tallness is dominant over shortness. Thus, you should know the phenotype of the following: TT, Tt, tt. From the data in Chart 2, find the ratio of TT to Tt to tt for each group of tosses.


Results of Coin Tossing
Heads/Heads Heads/Tails Tails/Tails
10 Tosses      
50 Tosses      
100 Tosses      

Results of Tossing Labeled Coins
TT Tt tt
10 Tosses


50 Tosses      
100 Tosses      

Conclusions:Answer these Questions:

1. What you tossed two coins 100 times in step B, which combination occurred most often- heads/heads heads/tails, or tails/tails? What was the ratio oof heads/heads to heads/tails to tails/tails?

2. When you tossed the coins that represented the traits for tallness and shortness, what was the ratio of TT to Tt to tt for 100 tosses?

3. From chart 2, what is the ratio of short plants to tall plants?

5. How do the result from the small sample compare to the larger one?


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Last Updated March 8, 2000 by Jacob