Laboratory Report Standards             


Ground rules:

* NO FELT TIP PENS! (the ink bleeds through the paper)

              * Number all pages.

              * Do not tear pages out of your lab notebook.

              * Draw a single horizontal line through misstreaks mistakes.

              * Draw a diagonal line through a page, or partial page, if you don’t want it graded.


Prelab Format:  (Record the following information in your lab book as directed by your instructor)

1.  Background information:  Include all class notes, terminology, etc. relevant to the lab

2.  Variables: 

Independent variable – the variable that has a condition or a value that you are 


                                             Dependent variable – the variable that has values which you are measuring.

                         Controlled variable – variables that are held constant.

3.  Equipment notes:  record instructions on using equipment and steps to eliminate 

      measurement error

4.  Safety issues

5.  Raw data:  record data here when instructed


Lab Report Format:

1. Title: Be descriptive and concise.                                Date(s): Tell when the lab took place.


2. Problem Statement: 

                       Include a description of the main idea you are investigating and a brief description 

                      of how you will carry out the investigation.

Example of a problem statement:   “To investigate the relationship between temperature and balloon diameter by heating a balloon and measuring changes in diameter?”


3.  Hypothesis:

A testable explanation (in “If...then...” form) based on observation, experience, or reasoning;

includes expected cause and effect.  Write a hypothesis when doing an experiment that tests   

                       a variable. 

Example of a Hypothesis:    “If temperature and balloon diameter are directly related, then as temperature increases the diameter will increase.”


  4. Materials: Write a neat list.


  5. a. Procedure: To be used if you write the experimental procedure; a numbered list of steps


      b. Procedural Changes: Used if you are given a list of steps to follow; write only the changes   

          from the steps given.


  6. Data Collection: 

•The initial recorded results (measurements, descriptions, or illustrations) obtained 

                        during the hands- on investigation. 

•All observations must include a title and any units of measurement

                        •Data tables are drawn with a ruler and large enough to write legibly.

                                          Example of a data table:

                                           Data Table 1: Change in diameter of balloon with temperature change

Temperature (o C)

Balloon Diameter (cm)














7. Data Processing:

•Transform the initial results, to make graphs and calculations, after the hands-on investigation is complete.

                        •Graphs have a title and are drawn with a ruler

•Use at least half a page for your graph.

•The independent variable belongs on the x axis.

                         •Calculations have a label, begin with the general formula, show numbers and units.


Example of graph:

                                Change in diameter of balloon with temperature change


                                Example of calculation:

Calculation of average temperature


General formula                                                   Substitutions                   Answer

                     Avg. temp  =  Temp1 + Temp2 + Temp3  =  16.2oC + 26.5oC + 39.4oC  =  27.4oC

                                                         3                                              3

   8. Results:

                        •With your problem statement in mind, summarize the results of the investigation,

                           supported by collected data.  If trends are apparent in your data, your description

  of these trends will be your results summary. 

•If you made a hypothesis, indicate whether the data supports your hypothesis or not;

  refer to data.


9. Conclusions:

                         A) Using appropriate vocabulary terms, explain the scientific concepts that are

                              important to the understanding of this investigation.  (This section will be an

                             explanation of WHY the trends in your data occurred.)

                        B)  Explain sources of unavoidable experimental error.  (In other words, explain how

                               any other uncontrolled variables may have affected the results.) 

                             Do not discuss mistakes, they should have been corrected.