Lab Report and Experiment Design

Formal lab report instructions for the Biology 110 laboratory

Overall assignment:

For Biology 110 you will be submitting one formal lab report for grading this semester. This lab’s formal report must be written in the 3rd person and in the past tense. Their length will vary depending on how concise each writer is, but the paper should be approximately 5 to 9 pages in length, including graphs. The pages are to have 1 inch margins, be double spaced, typed in Ariel or Times Roman 12 pt. and include supporting data (e.g., data tables, graphs, pictures or any other supporting material you wish to include) Each of the section headings must be labeled in your lab report. Skip lines between each section.

Sections

Title:

The title should describe the experiment you are conducting in some detail. You are not allowed to use the title you find in your laboratory manual. The title will be placed on a separate page with your name and the names of your lab mates, date, and course and lab section.

Abstract

The report abstract is a short summary of the report. It should be no more than one paragraph (100-200 words) and should include about one or two sentences on each of the following main points:

· Purpose of the experiment

· Key results

· Major points of discussion

· Main conclusions

It helps to complete the other sections of the report before writing the abstract, as these four main points can be drawn from them.

Introduction

This section should provide sufficient background information to the lab that will allow the reader to understand some of the principles you are investigating. This material can come from what you developed in your pre-lab write-up. It should include a specific statement of the question or problem under investigation, and statements about other goals of the laboratory exercise.

Why is this question important? How does this question relate to the “real world”?

This statement should be two paragraphs in length so you need to do a literature search on the topic(s) and incorporate this information into your introduction. Be certain to cite your sources. Clearly state the purpose of the experiment at the end of the section.

HYPOTHESIS:

The hypothesis section should contain a series of statements of what is to be expected to be observed during the experiment based on the background information you provided in the introduction. These statements should predict the outcome of each experiment or test based on solid scientific principles that you read from your text, the internet or your lab manual. Again, if the prelab was written properly, this section will come from the pre-lab write-up that you worked on prior to the lab. Use the “if…then….because” format.

In other words the hypothesis should convey what you think will happen during the investigation. It differs from a guess in that it is based upon prior knowledge or evidence. It should be supported by previously developed evidence and/or concepts.

For example:

Purpose: The problem is to study the effect of raising the temperature on the volume of a balloon.

Hypothesis: If the temperature of a balloon is increased, then the volume of the balloon will be increased and if the temperature of the balloon is decreased then the volume of the balloon will be decreased, because molecules move faster with increased temperature and move slower when cold. (Smith, 2000, p.54)

Materials and methods:

This section allows others who follow you to conduct the lab. This section includes the process of the experiment exactly as it was done in the laboratory. Usually the procedure is written out in paragraph form, but it may also be written out step by-step in the form of a numbered list. For this class you will provide a one or two sentence summary of the methods and cite the manual as your reference. If you make any changes in the methods they must be clearly described, in detail. No results would be included in this section; only include the procedures carried out. The source of the methods and materials must be provided, or cited, in this section as well.

Results:

This section contains all the results of the experiment, including:

a. Raw data (the weights, temperatures, etc.) organized into graphs or tables. Each graph, table, or figure should be labeled and titled properly. The key to making tables and figures effective is to refer to and explain each one in the body of the paper.

b. Note: required data for the results section:

(1) When writing up this report do not construct a set of raw data tables.

(2) For this particular set of experiments, i.e., the enzyme lab, you are required to produce two sets of graphs for each of the tests you conduct.

(a) A set of graphs expressing the change of absorbance over time and

(b) A set of graphs expressing the change in the rate of reaction over the changes in the specific treatment. For example you must have a plot of the change in the rate of reaction vs. the change in pH.

c. Important results in verbal form. For the main results that will be expanded upon in the discussion section, use complete sentences (i.e. “The percentage of acetic acid in vinegar was calculated to be 4.982 %”). This will help the key results to stand out from all the calculations, tables, and figures that normally dominate the results section.

d. Calculations. Usually, only a sample of each calculation is needed. For example, if the percentage of acetic acid in 10 samples of vinegar has to be calculated and then averaged, write out the calculation for only one of them, then mention that the calculation was repeated for 10 samples and give the average of all 10. Include the proper units for each of your observations in your tables and in the figures (cm. mL, etc.)

Important, do not include your methods in this section and do not discuss any of your results in this section.

An example of a properly constructed figure or graph

The figures presented below are typical as to what you should produce in your formal labs. In these examples you should notice several things:

· the presence of a period after “Figure #”;

· the legend (sometimes called the caption) goes below the Figure;

· units are specified wherever appropriate;

Some other general considerations about Figures:

· Big or little? For course-related papers, size your figures to fill about one-half of a page. Readers should not have to reach for a magnifying glass to make out the details. Compound figures may require a full page.

· Color or no color? Black and white is preferred. If you need to photocopy or fax your paper, any information conveyed by colors will be lost to the reader. Every aspect of your Figure should convey information; never use color simply because it is pretty.

· Title or no title? Never use a title for Figures included in a paper ; the legend conveys all the necessary information and the title just takes up extra space.

· Tick marks – Use common sense when deciding on major (numbered) versus minor ticks. Major ticks should be used to reasonably break up the range of values plotted into integer values. Within the major intervals, it is usually necessary to add minor interval ticks that further subdivide the scale into logical units (i.e., an interval that is a factor of the major tick interval). For example, when using major tick intervals of 10, minor tick intervals of 1, 2, or 5 might be used, but not 4.

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Bates College, 2012, retrieved from http://abacus.bates.edu/~ganderso/biology/resources/writing/HTWtablefigs.html#examples

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Bates College, 2012, retrieved from http://abacus.bates.edu/~ganderso/biology/resources/writing/HTWtablefigs.html#examples

Discussion and Conclusions

This is the section where you are discussing the results of the test and is the most important part of the report. This is the portion of the report where you demonstrate your understanding of the experiment and of its concepts. The function of the Discussion section is to interpret your findings in light of what you could find out about the subject of the lab investigation. The central idea that you are dealing with is 1) what do you conclude from the experiment and what is the significance of the results. In this section you can use the following ideas to complete this section:

1) What happened in the lab – was your hypothesis right or wrong or how do the results compare with your hypothesis? In other words do your results provide answers to your testable hypotheses?

i. If the results agree, re-explain why it happened, or

ii. If the results do not agree, provide possible explanation(s) why they did not. Do they suggest an alternative explanation of the process you are testing or was there an unforeseen design flaw in your experiment?

2) What you learned in relationship to the purpose of the lab (i.e., this is from the pre-lab write-up)

3) What further experiments might be done to further the study (i.e., this is from the pre-lab write-up)

4) How this applies to what we are learning – what are the real life applications

This is also the place to mention any unanswered questions or any errors that occurred during the lab.

The style of this section should be active whenever possible. Do not include wordy phrases; write concisely and clearly.

This section should be organized to address each of the experiments or points you presented earlier in the results section. Discuss each of the experiments or components in the same order as you presented them earlier in the results section and interpret the results in the context of the context of the problem you are solving. Do not restate the results; if necessary use bridge sentences to refer back to the data in the results section to data that are being interpreted.

Relate your work to the findings or other studies, or material from other internet sites or your text book. Also reference any outside resources used using the APA style format. Finally do not introduce new data or results into this section.

Literature Cited:

Whenever you use ideas from outside sources of any sort you must cite the source of the citation. APA format must be used for this assignment. (i.e., this is from the pre-lab write-up). The literature cited page is an alphabetical listing of the references you cited in the body of the paper or report you have written.

Formal Lab Grading Rubric

Name: _____________________________ Experiment: _______________________

Title and Formatting Instructions (5pts) ______

Is the title appropriate to the experiment? Are all the sections labeled?

Abstract (5pts) ______

This section should include a brief 1 to 2 paragraph statement indicating what was accomplished in the experiment. It should contain the following information:
a. A summary of the research question or problem.
b. A statement of the approach used in the experiment.
c. An overview of the methods involved.
d. An indication of the results or findings.
Introduction (20 pts.) ______

1. Appropriate Background Material – only when necessary (10 pts.)______

· Note: Do not include information that may be purely filler (i.e., material not needed to understand the experiment).

2. Purpose: (5 pts.) ______

3. Hypothesis (expected results – this may be in the results section) (5 pts.) ______

Note: this must be based on scientific facts from your text or other reliable scientific source.

Methods and materials section (10 pts.) ______

Provide enough detail for the reader to understand the experiment without overwhelming him/her. Describe special pieces of equipment and the general theory of the analyses or assays used.

When procedures from a lab book or another report are followed exactly, simply cite the work and note that details can be found there.

1. How will you measure your results – give a brief description (5 pts.) ______

2. Provide a list materials used, how they were used, (5 pts.) ______

and where and when was the work done (especially important in field studies)

Results (20 pts.) ______

Summarize the data from the experiments without discussing their implications. Concentrate on general trends and differences and not on trivial details.

Organize data into tables, figures, graphs, photographs, etc. Data in a table should not be duplicated in a graph or figure

Title all figures and tables; include a legend explaining symbols, abbreviations, or special methods

Number figures and tables separately and refer to them in the text by their number.

1. Data: The data was summarized (10 pts.) ______

2. Data: Is the data complete; are the calculations correct? (5 pts.) ______

3. Data Tables and Figures: Are they numbered and properly titled? (5 pts.) ______

Discussion (30 pts.) ______

This is a very important part of your notebook. It is the place where you make your important observations, and can discuss possible errors or anomalous results.

1. Are the results explained? (10 pts.) ______

2. How do the results compare with your hypothesis? (10 pts.) ______

i) If the results agree, re-explain why it happened (10 pts.) ______

Or

ii) If the results do not agree, provide possible explanation(s) why they did not.

Bibliography (APA or CSE Style only) (10 pts.) ______

1. Correct Format (5 pts.) ______

2. Proper citations within the report (5 pts.) ______

– are all ideas taken from other sources properly cited

TOTAL: ____________

Note: see comment on other side of page

Note: The total number of points awarded will also reflect the following technical problems

Loss of points:

1. The writing is not logical or is ambiguous, especially with pronouns and sequences

2. Excessive mistakes in spelling or grammar

a. Italicize, or underline, all scientific names (genus and species)

b. Spell out all numbers beginning sentences or less than 10 (e.g. “two explanations of six factors”).

c. Write numbers as numerals when greater than ten (10) (e.g., 156) or associated with measurements (e.g., 6 mm or 2 g)

d. Use the metric system of measurement and abbreviate measurements without periods (e.g., cm kg)

3. The paper was written in the first person or the present tense.

a. Keep your writing impersonal; avoid the use of the first person (i.e. I or we)

b. Use the past tense and be consistent within the report (*note: “data” is plural and “datum” is singular; species is singular and plural)