University High School Science Department
Formal Lab Report Format

Laboratory reports are the vehicle in which scientific information is passed on from the experimenter to others who have an interest in the scientific study. It is therefore very important that each student enrolled in a science class at University High School learn the proper format and procedure for writing a scientific report.

The following is a brief summary of what information is to be included in an acceptable laboratory report. Not all experiments will include all of the sections shown below. If your experiment (or your teacher) does not call for certain parts of the report format simply leave that section out.

Formal lab reports should always be word-processed or at least written neatly in ink. Never write any section in pencil. Graphs should be hand drawn or done by a computer-graphing program. The report does not necessarily have to be lengthy or elaborate. Scientific writing should be clear, concise and accurate. Correct spelling and grammar is always important and will have an impact on the evaluation of your report. Unless your teacher informs you that this will be a group report, each student in the lab group will be responsible for completing his/her own report. The report may include:

Title Page

This section includes your name, title of the lab and the names of all lab partners. The page should also include the course title, instructor, period and the date the lab was conducted

Title

 The title of the report must clearly reflect what the experiment was all about. This is not an appropriate place for creative or ambiguous titles.

Purpose

 This section of the report clearly states in one or two sentences what is to be studied in this experiment. What are you trying to find out in this experiment?

Hypothesis

 Write a brief statement outlining your specific expected outcomes of the experiment. The hypothesis is what you think will happen during the experiment. It differs from a guess in that it is based upon prior knowledge or evidence.

Materials

 List what equipment was used in your experimental setup. In many experiments, it may be helpful to include a detailed and labeled diagram of how the equipment is set up. Experiments involving measurements of electrical circuits must include a circuit diagram.

Procedure

 If you are reporting on an experiment with a written procedure, summarize briefly how the experiment was performed. Include only the basic elements the will give the reader an understanding of how the data was collected. Please do not include small details such as size of beakers, specific times, computer commands, or how specific equipment is to be connected together, etc. Do NOT just recopy the procedure from the lab book or hand out. Write the procedure as if you were describing the experiment to an interested friend.

If you are writing a report on an experiment of your own design, list the numbered steps of the procedure you followed. This should look a lot like the procedure section of your lab book

Safety

Write a short statement outlining whatever safety precautions might apply to the experiment. Consider the potential dangers of flammables, corrosives, toxins, sharps, heat or cold, among others. Eye protection is required for experiments involving the use of chemicals, boiling water, dissections or the possibility of flying projectiles

Experimental Data

 This section of the report will contain the raw data collected during the experiment. Experimental data may take the form of qualitative observations made during the experiment. Observations may include color changes, new products formed, phase changes, sounds, lights, positions or other non-measurement observations. This type of information is often best given in paragraph form where your describe your observations during a particular step. Include in your description what you did and what happened when you did it. Do not attempt to include interpretations of what happened at this time. This section is for raw data only.

Data may also take the form of numerical measurements collected during the experiment. Quantitative Data should be included in a data table with clearly labeled headings that include the units used. Do not ignore suspected faulty data but include it you report. Later, in your CONCLUSIONS, you will have the opportunity to explain why you have decided not to include the suspected errors in your analysis.

Charts and Graphs

 To look for relationships in the data it is often of benefit to graph the data collected. Make sure all graphs and charts are fully titled and labeled. See handout on how to construct a scientific graph for format instructions.

Sample Calculations

 Every time that you perform a new calculation for data analysis, show a sample calculation of how it was done in this section of your report. Show a sample for each type of calculation done in the experiment, no matter how trivial it seems. Use data from your experiment in your sample calculation, not made up numbers. Fully label each calculation so that the reader understands what you are calculating. Show the equation used for each calculation. Make sure that each measurement has the proper units and that each calculated result is given the correct number of significant digits. If a calculation is repeated in the experiment, there is no need to show it more that once.

%Error: calculation which determines how close your experimental value is to the accepted value (as always, show your work)

                     % Error  = |accepted value - your value|
                                                accepted value
If one of the analysis questions below asks for a calculation, show the work in the Questions section not Sample Calculations.

 

Questions

 All analysis questions found at the end of the experiment are to be answered in complete sentences (except calculations, where you need to show your work). One or two word answers are never acceptable. Do not rewrite the original question; instead, word your answer such that the question is obvious from the wording of your answer.

Conclusions

 This is the most important part of your lab report. It is here that you answer the questions asked in the purpose. Your conclusion should always be stated in terms of what you said your purpose was. Did the experiment verify your hypothesis? How do you know?

Begin your conclusion by restating your purpose and/or hypothesis. In a sentence or two, indicate how the experiment was conducted. State whether the results verified or refuted your hypothesis. List the evidence or logic from your experimental results that lead you to that conclusion. Be specific. If your results did not agree with the expected results, how far off were you from the accepted value? A percent error might be appropriate here. Is this error significant? Looking back on how the experiment was conducted, identify several sources of error. "Experimental error", "measurement error", "human error" and "calculation error" are not acceptable statements of error. Be much more specific! Your discussion of error should include the effects of each source with regard to both magnitude and direction. If you were to do this experiment again, how could you modify this experiment to improve your results?

Many of the points made above may have been previously discussed elsewhere in the report. Do not leave them out of your conclusion! Your conclusion should be able to stand alone without the rest of the report.

 

All reports should be signed and dated by the author at the bottom of the report. The date should reflect the date that the report is submitted.

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