A Quick Reference for Laboratory Report Writing

Prepared for Covenant University Engineering

By JASPER

Overview

This document describes a general, adaptable format for laboratory reports. The goal of laboratory reports is to document results and communicate their significance. A good laboratory report does more than present data; it demonstrates the writer's comprehension of the concepts behind the data, and the significance of the results.

Typical Components

• Title Page
• Table of content
• Abstract
• Introduction
• aims and objective
• literature review
• Methodology
• precautions
• list of material/equipment
• Experimental Procedure or results
• Discussion Results

• Conclusion
• Recommendation,References
• Appendices
• Further Reading

1. The Title Page

The Title Page must contain the name of the experiment, the full names of lab partners, and the date. Submittal information (course name, number and instructor) must also be provided. Titles should be straightforward, informative, and less than ten words (i.e. Not "Lab #1" but "Effect of Grinding Time on Coffee Concentration"). Title page
         The title page should include:
        
             the name of the unit
             the name of the experiment
             the date you did the experimental work
             the names and ID numbers of students in the group and
             the name of the lab.

2. The Abstract

The Abstract summarizes four essential aspects of the report: the purpose of the experiment , key results, significance and major conclusions. The abstract often also includes a brief reference to theory or methodology. The information should clearly enable readers to decide whether they need to read the whole report. The abstract should be one paragraph of 100-200 words (the sample below is 191 words). The abstract is often written last.

3. The Introduction

The Introduction states the objective and scope of the experiment (or report) and provides the reader with background to the experiment. The relevance and importance of the experiment should be explained. The Introduction provides a preview of the content of the full report. From the Introduction, the reader should understand why the study was performed.Introduction
         This section introduces the reader to the experiment and briefly outlines theory and background information relevant to the experiment. You need to state any relevant  laws,  equations and  theorems you will be using or investigating, and you need to explain the different analyses used, such as  nodal analysis and  mesh analysis.

                
                           

Note on Verb Tense

• The experiment is already finished.  Use the past tense when talking about the experiment.

"The objective of the experiment was..."

• The report, the theory and permanent equipment still exist; therefore, these get the present tense when referring to these:

"The purpose of this report is..." "The Ideal Gas Law is ..." "The Spectrophotometer measures ...

4. Background (or Theory)

This section explains the scientific principles that apply to the experiment and are relevant to the analysis and interpretation of results. The background or theory section should explain relevant equations as well.Aim
             This section states the aims of the experiment. In any experiment, you aim  to
            do something.
             For example, you aim  to verify,  to
            investigate,  to measure,  to determine,  to compare or  to calculate.
             Use the verb form starting with 'to' (eg 'to investigate').
Avoid the noun form which often ends in '-ion' (eg 'investigation').
Aims can be written either in point form or in complete sentences.
            
             Example in point form
             Aims
            
                 To measure the resistance of a specimen of wire.
                 To determine the resistivity of iron.
          
             Example in a complete sentence
              Aim: The aim of the experiment is to determine the resistivity of iron by measuring the resistance of a specimen of wire.
          
            
          
             Choose the better wording from these examples of the aim section from two
              student reports.
                
                  Aim
                
                 To investigate the effects of passing electric current through    water.
              
                 An investigation of  the effects of passing electric current through water.
                
              
              
                  Aim
              
                 The aim of the experiment was  to verify Kirchhoff's Voltage Law.
              
                Verification of  Kirchhoff's Voltage Law.
              
              
              
              
                

5. Methods and Materials (or Equipment)

This section provides the source (company name and location) of all materials used, and the model and manufacturer for all specialized laboratory equipment, and a description of all methods of measurement. If a standard published method is used, it must be referenced appropriately.Method
      
         This section  briefly  reports the steps that you followed in carrying out the experiment.  Do not repeat word for word what is in the lab notes  but concisely summarise in your own words the key steps which were taken in the experiment.
        
         The Method section describes  what was actually done  and so the verbs are usually written in the past tense, passive voice (for example,  were connected,  was measured, was calculated).
        
         When you carry out an experiment, you usually follow a set of instructions. Here are the instructions for an experiment to determine the density of a steel sphere.
        
              Example

            Determination of the density of a steel sphere using a balance
            
                 First find the zero reading of the balance.
                 Then put the sphere in the left pan and put weights into the right pan to bring the pointer to zero and obtain the apparent mass.
          
          
      
      
         If you were writing up the Method section, you would have to change these instructions to a report of what was done. These instructions might then be reported as follows.
        
        
              Example

            Method

            First the zero reading of the balance was found. Then the sphere was put in the left pan and weights were added to the right pan to bring the pointer to zero. In this way the apparent mass was found.
        
        
         In this Method section, the verbs are  was found, was put, were added and   was found which are all verbs in the  past tense using the  passive voice.
      
         Change the verb in the instruction to the past tense passive form. For example: change  find to  was found.
      
        
             Choose the better of these two examples from the  Method section of two student reports.
            
                  Method
                  Connect four resistors with a 10 V supply and measure the open circuit voltage, and the short circuit current between A and B. Determine the voltage and resistance of the Thevenin equivalent circuit.
                  Method
                  Four resistors were connected with a 10 V supply and the open circuit voltage was measured. The short circuit current between A and B was also measured. The voltage and resistance of the Thevenin equivalent circuit were determined.
 

6. Experimental Procedure

This section describes the process in chronological order. Using clear paragraph structure, explain all steps in the order they were performed. If the procedure is properly described, another researcher should be able to duplicate the experiment.

The procedure is always written in past tense and passive voice.

Correct: Ground CacO3 was weighed on an analytical balance.

Incorrect: We weighed ground  CacO3 on an analytical/weighing balance

You weigh  CacO3 on an analytical/weighingbalance

Weigh the  CacO3 on an analytical/weighing balance

It should not be written in the same format as a laboratory handout, which instructs the experimenter to perform a series of steps.

7. Results and Discussion

This section presents the findings and interprets their significance. All results should be explained, analyzed, and interpreted.Results and Discussion
      
         Note that sometimes in lab reports it may be more appropriate to present the results in one section, called  Results, and then to discuss them in a separate  Discussion section.
         
         In the  Results and Discussion section, you present your results and discuss them by:
       
             commenting on the results obtained
             interpreting what the results mean and
             explaining any results which are unexpected.
       
       
         You  present the measurements made in the experiment and you then  compare your measurements to the calculations you made in your preliminary work or the published theoretical values.
         You need to:
       
             identify any discrepancies and
             to state them as a percentage.
       
       
         You also need to:
       
             identify any sources of error in your measurements and
             if possible, suggest how your experiment could have been performed more accurately.
       
       
          What should you aim for?
       
             Clear comparisons made between the calculations and the measurements with the discrepancy expressed as a percentage.
             Good explanation of the possible reasons for the discrepancy and the possible sources of error in the measurements.
       
       
       
              Example
             Here are some useful expressions to use if your measurements correspond well with your calculations:
           
                  The measurements  are consistent with  the preliminary calculations.
                  The measured values  agree well with the calculated values.
           
       
       
              Example
             Here are some useful expressions if your measurements do not correspond well with your calculations:
           
                  The measurements  are significantly different from  the preliminary calculations.
                  The measured values  do not agree well with the calculated values.
           
       
       
              Example
             Here are some useful expressions for explaining the source of errors:
           
                  The discrepancy  may be due to  human error.
                  The difference  may be the result of  incorrect calibrations.

Analysis and Interpretation

• What do the results indicate clearly?
• What is the significance of the results?
• Compare expected results with observed results. What ambiguities exist between the expected and observed results? Logical explanations should be provided.

• Analyze experimental error.

Was it avoidable? Was it a result of equipment?  If an experiment was within the tolerances, there can still be a deviation from the ideal. If the flaws result from the experimental design explain how the design might be improved.

• Explain results in terms of theoretical issues.

When comparing observed results to expected results, the expected results should always be based on sound scientific principles. These principles, along with relevant equations, should be provided in the Theory (or Background) section of the report.

• Compare your results to similar investigations.

It is desirable to compare your results to published results of related studies. If published information is unavailable, you may compare your results to those of other teams in the class.

• Analyze the strengths and limitations of your experimental design.

This is particularly useful if a new or original design has been used.

• Use Graphs and Tables to provide a visual summary of results

The results are often conveniently expressed using graphs, figures, and tables, but must always be explained in the text.

It is never acceptable to present data in a graph or table without explaining them. Results must always be explained and analyzed in the text.

It is never acceptable to simply present a table without specifically directing the reader to it in the text.

• Put Sample Calculations and Raw Data in Appendices.

Sample calculations and raw data should be put in an Appendix. Refer to these Appendices in the report by directing the reader to them for the specific information provided (never just leave it up to the reader to discover the appendices).

8. Conclusions

In this section the significance and implications of the findings are summarized. The conclusions must be consistent with the stated objectives and with the results. The conclusion might also be a place to discuss weaknesses of experimental design, and what future work needs to be done to extend the conclusions. 

All recommendations for future work should be positive, relevant, constructive, useful, and practical.Conclusions
      
         This section states whether the aims of the experiment were achieved or not, and briefly summarises the key findings.
       
         In the  Conclusions of this kind of report you need to:
       
             comment on how closely your measurements and calculations agree and
             summarise the main reasons for any discrepancies.
       
       
             Choose the better of these two examples from the  Conclusions section from two student reports.
           
                  Conclusions
                  Despite some errors, the law was verified.
                  Conclusions
                  Kirchhoff's current and voltage laws have been verified. The superposition theorem for a two source network has also been verified. The experimental results were             always within 1.1% of the calculated values. The discrepancies may be due to ... ... ...(provide a reason here!).

9. References

References must be included if information from outside sources is included in the report. Any material or information taken from another source must be specifically cited (footnoted) in the text, and the references should appear at the end of the document in endnote format. The References section is not simply a reading list of books and articles on the subject.

10. Appendices

The Appendices should include such elements as raw data, calculations, graphs pictures or tables that have not been included in the report itself. Each kind of item should be contained in a separate appendix. Each Appendix should have a letter designation (Appendix A, Appendix B, etc.) and a descriptive title. For example, the results section might begin by noting: "Laboratory Data for Coffee Concentration as a Function of Grinding Time." Make sure you refer to each appendix at least once in your report.

Format Requirements

It is important to prepare a laboratory report that reflects a high degree of professionalism. Keep in mind that this is a written record and is a reflection of your professionalism and competence. Every course instructor, boss, company, and agency that you work with throughout your career will have different format requirements, but you must follow them! All format guidelines are established to produce readable, visually appealing, clearly structured documents.

 Laboratory Report Format

 Using an impersonal style in lab reports
      
         Since scientific writing is usually presented in an impersonal, objective
          manner, the personal pronouns  I,  we, and  you are generally not used in lab
          reports. There are several ways of avoiding using personal pronouns.
      
         Use passive sentences
        
        
             Instead of
             Write
      
        
              We tested the specimen.
             The specimen  was tested.
      
        
              I measured the resistance.
             The resistance  was measured.
      
      
        

         Use third person pronouns
        
        
             Instead of
             Write
      
        
              I found that...
              It was found that...
      
        
              We concluded that...
              It was concluded that...
      
      
        

         Use the report or its various sections as actor
        
         Examples:

        
               This report presents...
               The results show...
      
      
                
                           

• Prepare all documents using a hand writen,using A4 PAPER.
• Paragraphs should be double spaced with the first line indented 0.5 inches.
• Use headings to provide structure and enhance readability. Headings should be in the bold format.
• Skip one line above and below headings.
• Use page numbering (pages before the Abstract should not be numbered. The Abstract starts on page 1). Pages should be numbered at the bottom of the page in the center.
• Figures and Tables must be numbered.
• Equations must be centered in the line and numbered, with the equation number right-justified.
• References cited should be provided as endnotes. All references should be complete, and in standard bibliographic format.

Books

Author, Title, Edition, Volume, Publisher,City, Year.

Cole, P.J., Haiku of Philadelphia, 2^nd ed., William C. Brown, New York, 1996.

Edited Books

Editor (ed.). Title, Edition ed, Volume. Publisher, City, Year.

Bergey, D.H., J.G. Holt, and N.R. Kreig (ed.), Bergey's Manual of Determinative Bacteriology., Williams and Wilkins, New York, 1984..

Reference format for Lecture Notes and Handouts

Author, Title, Course, Institution, City, Year.

Sheil, J, Laboratory Handout: Determination of Paint Composition, Experimental Methods in Egyptology, Columbia University, 1986.

Reference format for Journal Articles

Author, Title, Journal, Volume(Issue) Year, Pages.

S. Farrell, J. A.. Newell and M. J. Savelski, Introducing Chemical Engineering Students to Product Design through the Investigation of Commercial Beer, Chem. Eng. Educ., 36(2) 2002, 11-20.