Laboratory Write-Up Format
Lab write ups must be typed using 12 pt Arial or TimesNew Roman font. Graphs should be done using Graphical Analysis whenever possible. If you hand-make a graph, you must make sure to use graph paper and a ruler so that your work is neat and tidy. If your computer is giving you problems, you may use the school computers. If you print at the library, remember they charge 10 cents per page. Since it is your responsibility, I am not able to print your lab write ups for you.
Title:
Date:
Introduction or Abstract & Purpose: (may be a statement or a question)
Summarize the experiment in 50-120 words (It is helpful to write this section last)
Include background information.. A one or two sentence statement that provides the reader with the necessary background information to understand the relevance of the experiment.
Hypothesis: (must be stated in an “If...Then” statement)
Materials: list format
Procedure: step format (what, where, when and how much!) Include pictures/diagrams whenever possible to clarify the experimental set-up.
Safety: Note and describe all safety concerns or hazards
Results/Analysis:
Data: data must be arranged in charts, tables, etc. Graphs should follow if appropriate and clarify the data. Graphs alone are not acceptable.
Data analysis: discussion and analysis of the data.
Experimental error: discuss possible sources of error.
Conclusion: (three paragraph format)
1st paragraph - restatement of purpose and hypothesis
2nd paragraph - summary of procedure and data
3rd paragraph - concluding statement. Make sure you include "Data supports the hypothesis" OR "Data refutes the hypothesis" and explain why you believe this is so.
NOTE: If the lab involved actual experimentation, then a hypothesis is required and the conclusion is written as stated above.
If the lab was a demonstration or a skills lab and did not involve actual experimentation, then no hypothesis is required and the 3rd paragraph of the conclusion summarizes what the student learned instead of a concluding statement.
A Closer Look at Laboratory Write-Ups...Use the following only if you still need more information!
TITLES
A great scientific title relates the independent variable to the dependent variable. The most common expression for this is: "The Effect of ...the IV on ... the DV ." You are telling the reader in your title what you did (the IV) to cause a change (DV).
INTRODUCTIONS
The introductory paragraph to a lab write contains three basic parts:
rationale
purpose
hypothesis
The rationale can be thought of as general background information that led you to conduct the experiment. What everyday phenomenon stirred your curiosity enough that you asked a question that could be tested? It is usually an observation that you made. Sometimes it is something that you read. Keep in mind, however, that the rationale is BIGGER than the purpose. The purpose and the hypothesis will be specific to the experiment. The rationale tells the reader what led you do it. Are there unresolved issues out there that need answers? This information, if it was read, can (and should) be cited in the introduction. Your rationale can be in the form of the questions that you asked yourself. Some samples are forthcoming.
The purpose is a statement of what you hoped to learn by conducting the experiment. What did you hope the experiment was going to teach you? What question(s) is it designed to answer? It is suggested that you preface the purpose with, "The purpose of this experiment is to ..." . This way no one can be confused about it.
The hypothesis is specifically what you predict will happen. (We've been over this.) It should be written as an "If... then..." statement." The IV and the DV in the hypothesis should match the IV and DV used in the title! The IV and DV cannot change throughout the experiment. There is one more place where they will show up - again they remain the same.
EXAMPLES OF INTRODUCTIONS:
(Rationale) Advertisers claim that "M&Ms melt in your mouth, but not in your hands." (Purpose) The purpose of this study is to see if the advertisers claim can be supported. (Hypothesis) If M&Ms melt in your mouth and not in your hands, then after M&Ms are placed in mouths and hands for 5 minutes, only the M&Ms in the mouth will have melted."
(Rationale)In the evening it has been observed that insects are attracted to porch lights. All porch lights are not the same. Are the insects attracted to any type of light or light from specific bulbs? (Purpose) The purpose of this experiment is to test whether or not insects are attracted to specific types of light. (Hypothesis) If a fluorescent, "soft white", halogen and black light are illuminated at night, then insects will be attracted to only the "soft white" light."
(Rationale)Packages of TheraFlu direct the user to dissolve the ingredients in hot water, but no specific temperature is given. (Purpose) The purpose of this experiment is to determine at which temperature Theraflu dissolves most readily. (Hypothesis) If boiling, hot tap and cold tap water are used to dissolve Theraflu, then the Theraflu will dissolve most readily in the boiling water.
EXPERIMENTAL DESIGN
This model was adapted from "Students and Research" by Julia Cothron (1993)
This describes the way the experimental design will be written in your laboratory reports. It is a clear and concise expression of the variables. By looking at it, the reader can tell what you changed, levels of change, number of times it was done, what the control was, what you looked for and what you kept constant. All the parts of a great experiment.
Begin by drawing a box. The independent variable will go across the top of the box (in the first row). This is the same IV that we see in the title and the hypothesis, right? The next row below, will contain the levels of the IV. Divide the row into columns to account for every level that there is. Under the levels is the row for trials. How many times will you perform the experiment at each level of the IV? (Usually it is the same for each) You need to include this row even if you are only doing each level one time. Under the trials is the row for the control. If there is a negative and positive control they should both be identified here. Under the control, put the DV in a row. This is the same DV from the title and the hypothesis, right?" Under the DV is the row for your constants - what factors will remain the same for all experimental groups.
If every portion of the box is filled in correctly, your experiment will be soundly designed. The next step is to prepare the data tables. You want to have the table done before you collect data so you are clear about what sort of information you are looking for.
Data Tables and Graphs
The role of data is to allow you see if your hypothesis is supported or not. The data you collect from your experiment should be placed in an orderly data table. The data table is organized according to the experimental design. (Are you getting the feeling that this is like one big puzzle and the pieces are beginning to fit? Let's hope so!) Begin making your data table by dividing a rectangle into 2 columns. The left column represents the IV, the right side is the DV. Sometimes you will need a third column on the right for derived quantities (averages) or conclusive information. Repeated trials are shown in subdivisions of the DV, forming columns. Levels of the IV are subdividions of the left column forming rows. If the levels are numeric, they should be ordered from smallest to largest. The most important aspect of any data is that every row and column has a label - the reader must know what the information is. Data tables have titles as well. First, give them a number title , e.g., Table 1. Follow the number with a title relating the IV and the DV. It may be the same title you used for the entire experiment. Some tables will not have an IV-DV title. For example, if you are displaying some text-type information and the data is terminology, the title might be,"Table 2 Describing Colorimetric Indicators". Keep your lines straight and your boxes big enough to write in. You do a lot of work collecting that data so give it the respect it deserves.
Graphs
Refer to the graphs guidelines that I handed out in class. This should be a bright pink colored sheet and was to be put in your binder as reference. All graphs must be neatly hand drawn or use graphical analysis for a professional look. All graphs must be properly labeled and interpreted fully for the reader. Do not assume the reader will interpret.
Conclusion
The conclusion is the portion of the lab write-up where the experiment is summarized. It is designed to give the reader a synopsis of the lab without them having to read the whole thing (if this were published works; of course all of your will be read). Some parts of the conclusion are pieces of the puzzle that already exist, they will simply be put into the conclusion. Other parts of the conclusion require a thinking process that involves analysis of the data and the identification of trends within the data. While the conclusion is to be written in paragraph form (often it takes more than one!) if you take it a piece at a time it is not so overwhelming a task. The pieces are:
• description of the purpose
• procedural overview
• major findings
• restatement of the hypothesis
• comparison to other researchers
• notes, text, other sources
• plausible explanation
• recommendations for further study
• suggestions for experimental improvement
DESCRIPTION OF THE PURPOSE
The first statement you make to the reader in your conclusion is the purpose, or what you hoped to learn. This is the same purpose you wrote in the introduction. It wouldn't make sense to change your purpose at the end of the experiment would it?
MAJOR FINDINGS
The major findings are where you restate the data in the form of trends or relationships that you have found between the experimental variables. It is suggested that you first write a topic sentence that relates the independent variable to the dependent variable and make reference to the appropriate table or graph. For example, "The effect of nasal strips on running performance is depicted in Table 1," or, "Table 4 depicts the effect of Nutrasweet on weight gain in mice." The next sentences should report an analysis of the data. Were there any patterns to the data? Did one factor influence another? Major findings can be detailed and repeat actual data from the tables; however, it is the identification of trends and relationships that indicate you have an idea of what the data might mean.
SUPPORT OF THE HYPOTHESIS
After you have identified the trends in the data you must state whether or not these data support, or do not support, your hypothesis. Remember - we are not proving anything. Be careful of your wording **The hypothesis does not do the supporting - the data does!** Your experiment is not "less worthy" if your hypothesis is not supported. The goal was to learn something and that's what counts. Some writers like to restate the hypothesis and then state whether or not the data supported it, or not. This is a more detailed way to do this and very acceptable.
COMPARISON
How does your experimental research compare to what others have found? This is the part of the conclusion where you credit others who have performed the same, similar or related studies. Is the work you've done referenced in your notes from class? Is there related information in the textbook or another book? Can you find a similar lab with results described on the Internet? The resources for comparison are endless. Sometimes you may be allowed to reference the findings of your classmates. Were your results the same as theirs?
It is important to reference correctly. It is not enough to just mention the reference. For example, "The data in this study closely resembles the work of Dr. Whozit," or "The findings from this experiment are supported by our notes from class." References such as these do not give the reader enough information to validate what you are saying. A complete reference of another study will include a comparison of methods, actual data (if available) and a brief statement of what was found. For example, "In 1997, Dr. Whozit from the University of Whatzit, performed a similar study using white mice fed Nutrasweet or table sugar. He found that after six months the mice eating Nutrasweet had gained 2 grams while the mice eating table sugar maintained their weight. It was concluded that Nutrasweet may not be the answer to weight loss." If you are referencing your text or notes, "The findings are supported by the class notes (dated...) which state that ....." Or take a direct quotation out of the text or another source (see referencing below). The key is to provide enough information from the comparative source to support, or not support, your findings. Yes, it may be that your findings are not supported by the work of others - you mention this too. Then you get a chance to explain it away in the next section.
Referencing
In the comparison section you are referencing a previous work. This information needs to be cited correctly. Give credit where credit is due. You will be provided a table of correct bibliographic referencing. Complete references go at the end of your document. Within your document you cite an author by putting their work in quotation marks and follow the quote with their last name and the year date in parentheses. For example, "Young volleyball players often lack proprioceptive skills." (Stowell, 1995) You can also reference the author within the sentence. Stowell (1995), in "Coaching Volleyball", states that young volleyball players often lack proprioceptive skills. A terrific resource for citations, and writing in general, is: Sebranek, P.,Meyer, V. and D. Kemper. "Writer's Inc.".Wilmington, MA; Houghton Mifflin, Co, 1996.
EXPLANATION
In this section you actually get to apply some reason to the findings. What plausible explanation can you offer for what you found through the experiment? How does your explanation compare to what others have found (you just did this)? Why or why not do you think your data supported your hypothesis? Why didn't your data support your hypothesis? As long as you are thinking logically and with regard to the experiment it is hard to offer a poor explanation.
RECOMMENDATIONS FOR FURTHER STUDY
The last part of a conclusion asks you to continue being curious. What other questions do you have that might lead to a related experiment? What changes can you make that may produce differing results? This is where you let the reader know that there other investigations to be performed that will add to the experiment just reported. As long as suggestions are consistent with the experimental principles they are appropriate.
IMPROVEMENTS
Included in the same paragraph as your recommendations should be your suggestions for improving the experiment just performed. Seldom does an investigation come along that leaves no room for improvement. Were there sufficient trials? Were any substitutions made with the materials? Were things measured as accurately as possible? Was any data lost or misreported? How can this be avoided next time? What were some sources of experimental error? Keep your suggestions related to the experiment. This is not where you tell your teacher improvements such as, "Things would have been better if we got to choose our own groups." Likewise, do not attribute all errors in the experiment to "human error". It's not against the law to think! YOU CAN DO THIS!