PREFATORY NOTE: All requisite copyright restrictions apply. These excerpts, with the exception of the CONTENTS section, include in their entirety only text penned personally by Neil A. Durso, one coauthor among several. Accordingly, included sections/chapters are links, and those not included are in gray in the CONTENTS section. The text was prepared by OCR (scanner), and, subsequently, manual efforts at error correction.

Writing in the Biology Curriculum - Penn State
The Scientific Method
Organization In Science Writing
Writing And Science

The Purpose Of A Protocol
Components Of A Protocol
Diagnostic Exercises

Purpose Of A Lab Report
Components Of A Lab Report
Diagnostic Exercises

Purpose Of An Essay
Types Of Essays
Preparing To Write An Essay
Components Of An Essay
Refining Your Essay
Diagnostic Exercises

Common Stumbling Blocks
Usage Problems
Problems With Style
Manuals On English Composition
Manuals On Scientific Composition



The fundamental information presented in science course lectures is the end-product of years or decades of research, but students may be given only a glimpse of how that knowledge was discovered. An understanding of formal inquiry and written communication in science can seldom be accommodated in lecture presentations. The instructional laboratory affords a forum to attain this objective - if enough laboratory time can be devoted to developing the skills that are the backbone of scientific enterprise.

Instructional laboratories in biology courses include written assignments designed to challenge students to learn (1) how scientific inquiry proceeds by requiring students to prepare and conduct experimental protocols, and (2) how the fruits of that inquiry are communicated effectively through lab reports that are designed to resemble professional science documents rather than fill-in-the-blank, question-answer forms. The introductory biology courses have recitation meetings on alternate weeks which permit more attention to be focused on the process of writing. This manual is intended for science students unfamiliar with the forms and forums of scientific writing and, hence, can serve as a general guide.

Chapter 1, INTRODUCTION, presents steps involved in the writing process in general and proceeds to the conventions used in science writing in particular. In reviewing elements of the scientific method, the common terminology of science is introduced. Then parallels between the scientific method and the process of writing scientific documents are illustrated.

Chapter 2, SCIENTIFIC PROTOCOLS, discusses the written form of experimental designs. Experiments are described as a formal means of testing hypotheses. The chapter emphasizes the use of null hypotheses to eliminate possible explanations for observed phenomena. Hypotheses are portrayed as the effective guide to designing experiments. The use of visual aids is stressed (1) as a way of ensuring that each experimental step has been carefully thought through, and (2) as a way of minimizing the number of words used to describe methods and data analysis.

Chapter 3, LAB REPORTS, logically follows the chapter on designing experiments. This chapter provides guidance in presenting experimental results in formats that reflect scientific research reports. Lab reports present the hypothesis being tested and describe how it was tested. Experimental results need to be presented in a way that readily permits their interpretation. Again the evaluation of the hypothesis being tested is the fundamental aim, and instructions on discussing thoughts that proceed from this evaluation are provided.

Chapter 4, ESSAYS, considers a different form of writing in science. Critical evaluation of someone else's science is as important as evaluating one's own. This chapter provides guidance in writing documents intended (1) to evaluate whether other authors have achieved their purposes in their writings, and (2) to compile and discuss information from various sources on a common topic. The chapter's broad applications extend this manual's utility to science courses which do not have instructional laboratory components.

Examples to illustrate good and poor practices are provided throughout Chapters 2 and 3. The poor examples are drawn from the authors' experiences as instructors, and so represent actual errors common in instructional laboratory writing assignments.

Each of Chapters 2 through 4 is followed by a checklist comprising elements of the respective document. Students may use these both to outline their documents and to check that the elements have been included in their final documents prior to submission. Similarly, instructors may point out deficiencies by reference to the checklists.

Diagnostic exercises were designed to help both instructors and students to evaluate the students' strengths as well as their weaknesses that will require more attention. The exercises corresponding to each type of document are found at the ends of the chapters. They can be used to introduce each type of writing and may prove more fruitful than simply giving an example of a satisfactory document. Students may intuitively appreciate why a sample document is good, but simply reading one affords only a marginal level of engagement. The diagnostic exercises engage both thinking and writing skills involved in preparing the respective documents. Thus, students are challenged to think in productive ways before ineffective habits can arise on a full document.

The last section of the manual is Chapter 5, CONVENTIONS OF ENGLISH COMPOSITION. (Pause to roll your eyes and yawn.) The section is neither a grammar lesson, nor a usage guide, nor a commentary on style; instead, it contains a nonexhaustive listing of poor writing practices that appear in science courses. It can be a useful checklist for students to use prior to submitting assignments. Instructors may point to students' writing habits that are explicitly addressed in the chapter. And students can highlight poor practices continually appearing in their own writing, or add entries as reminders of their poor habits. This chapter is in no way intended to replace style manuals ,some of which are listed - we strongly recommend that students obtain and use one.

Richard Cyr, Ph.D., served as the course coordinator for introductory biology and has presented a large portion of the lectures for that course in which 800 to 1200 students are typically enrolled. Under Dr. Cyr's supervision, the primary authors of this manual - Jonathan F. Dunski, Neil A. Durso, and Jennifer M. Hay - were laboratory instructors for introductory biology for a combined total of 9 semesters, 17 sections. In addition, these authors have served as teaching assistants in a variety of other courses in the Department of Biology. Hence, both evaluative feedback provided by students under their instruction, as well as their own practical experience in what methods are effective in directing students toward the two objectives described above, are reflected in this manual's authorship.

The authors thank Christopher J. Paradise for his guidance as the introductory biology laboratory coordinator. We also thank Linda R. Maxson, Christopher J. Paradise, Stephen W. Schaeffer, and Thomas S. Whittam for reading the manuscript and for their suggestions.





The fundamentals involved in scientific writing and the centrality of the scientific method in such writing were presented in Chapter 1. A protocol is a form of scientific writing that adheres to those generalizations. The purpose of a protocol is to provide a formal design to scientific experimentation. A protocol serves as a guide to performing an experiment, but, just as importantly, it serves to provide a reason for doing the experiment and a framework by which the results can be meaningfully represented and interpreted.

Who might author a protocol? Perhaps a researcher has developed a method that would be useful to colleagues, so they request a protocol to repeat the technique with reasonable precision. Perhaps a science student pursuing a doctoral degree proposes an experiment to members of the committee that grants the Ph.D. so they can assess the likelihood of meaningful outcomes. More commonly, perhaps a student in an undergraduate laboratory course must propose an experiment to the instructor prior to performing the experiment.

The style in which a protocol is written should, of course, be consistent with its purpose. Do not write fluff. It would indeed be a rare person who reads a protocol or lab report for entertainment purposes before retiring to bed. The reader of a protocol is interested in being informed concisely and accurately. There is no reason for fanciful locutions, creative and poetic phrases, or unnecessary expressions. These are opposed to the document's purpose. A reader may consider them an annoyance, or even a means of trying to hide the authors' incomplete understanding of what is written. Neither of these perceptions will benefit the author.



The variation in the forms of protocols are likely to be dependent on (1) the complexity of the experiment, and (2) the level of detail or the length limitation specified by an instructor. An instructor may ask, for example, that two or more sections be combined into one; however, all of the elements covered below should certainly be present in some form.


A protocol's title should be descriptive and accurate. The Title should indicate the independent variable, the organism or system examined, and the dependent variable. (For reviews of these terms, see Chapter 1 under THE SCIENTIFIC METHOD, or see the MATERIALS AND METHODS section below in this chapter.)

Poor Titles:
Why Plants Might Grow Faster at Night.
Assessing Effects on Beanstalk Growth.
Assessing Effects of Light on Plant Growth.

Good Title:
Assessing Effects of Light Intensity on Beanstalk Growth.

The instructor should also specify what format other information (e.g., author names, Id. numbers) should assume on the title page.


The Purpose section conveys the question which the protocol is designed to address, and contains these essential elements:

  1. sufficient background information
  2. a formal statement of the experiment's purpose
  3. a hypothesis to be evaluated by the experiment
  4. a brief but meaningful summary of procedures

Sufficient background information

What constitutes sufficient background information? In an undergraduate course, this information is likely to come from simpler sources such as the authors' own observations, lecture notes, course textbooks, lab manuals, or preliminary experiments performed previously. Professional researchers draw this introductory information typically from "lab reports" of previous experiments published in journals for these purposes.

Formal statement of the experiment's purpose

How does one formally state "why" an experiment is to be performed? This should flow rather logically from the introductory statement(s); it is not intended to be a justification of why an experiment is important or why the findings might be vital to society. For example:

Beanstalks have been observed to grow at different rates under various conditions. To determine whether different light conditions contribute to the growth differences, beanstalk growth under several light intensities will be measured.

The first sentence provides introductory information, and the second sentence is a simple explanation of why and how an experiment will be performed.

Hypothesis to be evaluated by the experiment

Hypotheses are absolutely essential elements of science, and their use is reviewed throughout this manual. Hypotheses are demanded in every form of science and scientific writing because they explicitly (and not subjectively or intuitively) direct a line of scientific inquiry. Null hypotheses were described in Chapter 1, and the formulation of null hypotheses provides a powerful means to appreciate the objective and refined knowledge gained by the scientific enterprise.

It is the method by which scientific knowledge is acquired that makes such knowledge objective. "Objective" means that it is widely acceptable and not dependent on personal, or subjective, opinion. Because hypotheses cannot be proven, only supported or disproved, good scientists seek to disprove hypotheses. This is an effort to rule out certain possible explanations for an observed phenomenon. On the other hand, every time support for a hypothesis is found, a more specific explanation can almost always be proposed. By eliminating possibilities and focusing on unexamined explanations, scientists more efficiently approach a deeper understanding. The process by which this understanding is approached (the scientific method) tends to produce objective knowledge.

The optimal way to proceed toward objective knowledge is by testing null hypotheses, which propose that an experimental treatment will not produce an effect. Consider the null hypothesis:

Light intensity does not affect beanstalk growth.
See how this simple, testable statement serves as a guide to designing an experiment with a simple and dear purpose? Evidence to reject this hypothesis would be a step toward a deeper understanding that can be pursued. Hence, science is a process; some explanations are eliminated, others become good candidates to pursue.

Understandably, the concept of null hypotheses is often troubling; however, it must be grappled with. Bounce the idea off classmates, and particularly challenge the instructor to provide satisfactory descriptions. Formulating null hypotheses is a skill that requires practice and guidance from instructors.

Summary of procedures

There are usually many ways that one hypothesis can be tested. For example, will beanstalk growth be measured in terms of fresh weight, dry weight, height, number of leaves, or stem thickness? At what developmental stage will they be measured? For how long will measurements be recorded? Thus, a brief explanation of the selected approach should be included in the Purpose:

Beanstalks germinated under the same conditions will then be exposed to different light intensities, and the heights of the seedlings will be recorded over 12 days.
Details belong in the next section, but it is useful to a reader to know the general approach if, for example, the experiment is one of several that have the same purpose but use different approaches.

A well prepared Purpose section, which is clearly understood by both writer and reader, effectively guides the remainder of a protocol's logic. The methods for testing the hypothesis become evident. When it is clear what the method should be, it becomes clear what sort, type, or form the resulting data will take (and therefore, the optimal way to present it). And, of course, the type of data and the way it is organized for analysis dictate how easily a hypothesis can be evaluated.


This section explains the procedure used to test the hypothesis. Enough detail must be given or cited so that another person or group can also perform the experiment with reasonable precision and obtain directly comparable results. As the title makes clear, it is most often desirable to combine the two components; if methods are appropriately described, the materials used should be obvious.

The essential parts of the Materials and Methods section that should be made explicit include three components of the experimental design which were introduced in Chapter 1:

  1. independent variables, those manipulated; similar to "input."
  2. dependent variables, those measured; similar to "output."
  3. controls, or control experiments.

As described in Chapter 1, the scientific use of the term "control" is distinct from its other more common uses. A rigorous and universal definition of "control" is elusive because different experiments require different controls. In the broadest sense, controls are used to determine that experimental results are due specifically to the treatments intended. In other words, does the experiment really investigate what the Purpose supposes it does? For example, if one intends to investigate the effects of light intensity on beanstalk growth, one needs to ask oneself if light intensity is the only independent variable included in the experiment. Could soil moisture or temperature (both of which affect plant growth) also vary with light intensity? So, more technically phrased, controls are used to ensure that measured changes in a dependent variable (e.g., growth) result specifically from the independent variable (e.g., light intensity).

With every assignment, an instructor should intensely challenge the students to come up with excellent controls, not simply obvious ones, or insufficient, approximate controls. Sometimes the truly powerful controls might be too elaborate to be practical in a limited lab, but students should nevertheless be held responsible for presenting them. Thinking hard about controls is one of the more excellent ways to appreciate science. Much like a good null hypothesis, controls serve to increase understanding by eliminating possibilities.

The level of detail in the Materials and Methods section depends on what the audience (instructor) demands. It is often unnecessary to include much information on procedures already described adequately in a laboratory manual, so cite the manual whenever possible (Chapter 1 provides citation directions). If this practice is chosen, be careful to be specific in cases where the manual is general or presents several options.

Sometimes an instructor may ask that some seemingly trivial details be included for worthwhile reasons: so that the experiment can be performed rapidly; so that a critical procedure is not overlooked or inaccurately executed; so that the instructor can evaluate whether the authors understand what materials are available and how the materials are to be used properly. Understand the specifications of the instructor clearly.

Practice and instructional guidance are required to discern how much information should be presented in the Materials and Methods section. Again, protocols are to be brief but informative, so avoid the tendency to over-describe methods. Is the following passage both informative and brief?

We will measure light intensity using a light meter that has a range of 0.0 to 6.0 kW/m2. Heights will be measured in mm using a 6.7 cm ruler.
Are these statements necessary? Isn't a ruler needed to measure height? And why is the range of the light meter or ruler important, unless using a slightly different method or instrument might affect results. Furthermore, when data are presented, the units will be indicated, so save words.

Another means of keeping protocols brief and reader-friendly is the effective use of illustrations. Diagrams or flow charts of methods, treatments, and/or apparatuses often shorten, and more importantly, clarify Materials and Methods sections. Such visual aids are pleasing to readers, if they are prepared thoughtfully and accurately. They typically require some description, but avoid redundancy - do not describe what is already evident from the diagrams.


Similar to the Materials and Methods section, the Data Presentation section (1) flows logically from the Purpose and (2) indicates how the Purpose will be attained. Therefore, the language of the Data Presentation section should reflect that used in the preceding sections.

After the procedures in the Materials and Methods section have been carried out, measurements or observations will have been recorded. This data is called raw data because it is not yet "cooked" - ready to be served to a reader for pleasant consumption. The objective of the Data Presentation section is to explain how the raw data will be organized, then analyzed (e.g., by mathematical calculations, statistical analyses, assembly into a table, and/or graphing). These analyses produce, of course, analyzed data from the raw data. The ultimate reason for the conversion from raw to analyzed data is to serve the Purpose - i.e., for evaluating hypotheses by clear, simple figures that present data "at a glance."

Consider the following general organizers when writing a Data Presentation section:

  1. In what organized format will the raw data be collected as methods are performed?
  2. How will the raw data be manipulated, analyzed, and presented for clear interpretation of hypotheses?
  3. How will the hypotheses be evaluated based on what can be learned from the analyzed data?

1. Data collection format

This element indicates to the audience what type or sort of data will be collected while carrying out the methods. It should be quite clear from the Materials and Methods section whether measurements of weight or height, records of color or shape, etc., will be recorded. Data acquisition tables appropriate for collecting raw data should be prepared before performing experiments (1) to facilitate raw data acquisition during the actual experiment, and (2) to indicate to an instructor that the proposed experimental design is truly understood by the authors.

A third benefit of data acquisition tables is that they can serve to simplify Materials and Methods sections; therefore, some instructors might prefer that they be included in the Materials and Methods section. To appreciate how much smoother a Materials and Methods section could be if a data acquisition table is presented, consider the following from a reader's point of view:

Measure the heights of 12 beanstalks - 4 beanstalks at each light intensity of 1, 3, and 5 kW/m2, and take measurements 3 times on each plant 4, 8, and 12 days after they germinate, for a total of 36 measurements.
Imagine how much clearer this passage would be if the reader was shown a blank table with spaces for all the measurements in clearly labeled columns and rows. In addition, this passage could be shortened by referring to the table. Examples of such tables can be found in most instructional laboratory manuals.

Raw data rarely permit an easy evaluation of hypotheses, so the next step in preparing a Data Presentation section is to consider how the data are to be reorganized and presented.

2. Analyses of raw data and presentation of analyzed data

Methods of data analysis depend on specific experiments, so all possibilities are not discussed here. But whenever data analyses will be performed, it is critical to include a precise and accurate description of, for example, calculations or statistical tests:
Poor:We will calculate the average growth rate for each light intensity.
Good:The mean height of the four plants grown at a light intensity of 1 kW/m2 will be divided by 12 days to calculate average daily growth rate at 1 kW/m2.

If a data acquisition table with specifically labeled columns and rows is already included, this description can be further simplified. Perhaps a simple formula can describe the same calculations that will be repeated for each section in a table. These steps will also demonstrate to an instructor that the authors fully understand what will be done.

In the present example, Average Growth Rates over 12 days (AGR12) for beanstalks under different light intensities could reported:

At 5 kW/m2, AGR12 = 30m/12 days = 2.5m/day.
At 3 kW/m2, AGR12 = 30m/12 days = 2.5m/day.
At 1 kW/m2, AGR12 = 18m/12 days = 1.5m/day.
These data could be shown in a table, but what if beanstalks under 5 kW/m2 grow slowly in the first 4 days, and then speed up between 4 and 8 days? Furthermore, what if beanstalks under 1 kW/m2 grow faster during the first 4 days than those under 3 kW/m2, but then slow and never grow as tall as those under 3 kW/m2? These scenarios are shown in these graphs:

The AGR12 does not reveal that the growth rates varied over the 12 day periods. Consequently, the averages would not be greatly effective for evaluating a hypothesis. In fact, a misleading evaluation could result. It is possibilities like these that make graphs a preferred way to present analyzed data.

From the graphs shown above, the following general observations emerge:

  1. If several lines (or curves) are presented on the same graph, differences in the steepnesses (slopes) between the various light intensities could be more clearly and directly compared.
  2. A graph shows much data at a glance; the slopes are the growth rates, and they are shown 'visually rather than numerically.
  3. The final mean heights are easily compared on the graph.

A graph is most easily prepared from a table of analyzed data. A blank analyzed data table should always be included in a protocol because it makes clear to readers what steps will occur in converting raw data to a graph. It is far easier to explain which columns in an analyzed data table will be plotted on an x-axis and which on the y-axis. Y-axes are used for dependent variables, and x-axes are used for independent variables; thus, it is said, "The dependent variable (y) is a function of (dependent on) the independent variable (x)." A final step in clarifying this process for a reader is simply to include a sample graph with the axes labeled and units indicated.

In conclusion, at least in the example developed here, a graph is the best way to present the analyzed data because it makes the next component of the Data Presentation section easier.

3. Evaluation of hypotheses based on analyzed data

The results of an experiment proposed in a protocol, of course, are not yet known. Nonetheless, the authors shall have carefully considered this question: Will the analyzed data be presented in a way that makes the hypothesis easy to evaluate? Generally, there are three possible outcomes in evaluating an hypothesis. (1) It must be rejected. (2) It is supported. (3) The evaluation is inconclusive because results do not have a straightforward interpretation.

Recall that experiments are most easily designed around a null hypothesis and that good scientists seek to disprove hypotheses.

The null hypothesis is rejected if the curves show the trend that more and faster growth occurs at higher light intensities. In other words, light intensity does appear to affect growth. The same conclusion would apply if the trend were reversed (lower intensity, more and faster growth).
The evaluation of the hypothesis leads to a definite conclusion, and rejecting a hypothesis is more definitive than supporting it (because hypotheses cannot be proven). This outcome leads to the proposal of deeper explanations. One might ask, "Because light intensity does appear to affect growth, what wavelength of light is most effective?" (what null hypothesis would guide an experiment to address this question?)

The second possible outcome of evaluating a hypothesis, supporting it, would also lead to the proposal of other explanations:

If the beanstalk growth curves look similar at all three light intensities, the null hypothesis presented above is supported, and another cause for the growth differences should be investigated.
So either rejecting or supporting a hypothesis directs subsequent investigations which can increase understanding further still. Perhaps the effect of temperature or humidity could be examined. It is in this powerful sense that science is a method, a process - it proceeds.

The two preceding passages are similar to what should appear at this point in a protocol. They describe how the hypothesis will be evaluated based on the possible appearances of the analyzed data. Including some sample graphs with some hypothetical curves can clarify these passages further. The cases in which a hypothesis will be rejected or supported are relatively easy to anticipate. However, the third possible outcome of an experiment - i.e., results which are not easily interpreted - is difficult to include in a protocol that has not yet been executed. In some cases, nevertheless, the authors might have an idea about complications arising from the experiment or analyses. These foresights should be included in this section of a protocol.


As always, list all references cited, using the standard format described in Chapter 1.

In conclusion, all of the points presented in Chapter 1 apply to a protocol. Not only are the points regarding formats, tables and figures, references, etc. applicable to protocols, but so are the general points about the process of writing. If the preparation of protocols is a group effort, the authors should take full advantage of the individual ideas and self-evaluations of all members. The revision process is particularly important. Consider seriously that an instructor who has reviewed a large number of protocols can quite easily recognize those that are rough drafts and have not been conscientiously revised. In addition, spelling and proper English standards are immensely important because these indicate to an audience the seriousness with which a document is prepared. Any written communication carries more authority when it appears to have been written by well-educated authors.


Prior to submitting a protocol, review this list with coauthors. This checklist should also prove useful as an outline in preparing the first draft of a protocol.





  • independent variable
  • experimental organism or system
  • dependent variable


  • instructor's name
  • correct names of all authors
  • laboratory section number
  • other, as specified by instructor


  • sufficient background information
  • statement of the experiment's purpose
  • informed and testable hypothesis to be evaluated
  • summary statement of procedures


  • experimental set-up (organism or system, conditions, etc.)
  • accurately cited procedures from other sources
  • selected procedural options made explicit
  • clear figures of set-up and/or design
  • figures referred to in written text
  • no redundancies between figures and written text
  • independent variable
  • dependent variable
  • controls
  • footnotes on better controls that cannot be done


  • blank raw data acquisition table (perhaps in section above)
  • description of how raw data might be manipulated
  • blank analyzed data table
  • complete description of analyzed data presentation (sample)
  • description of how hypothesis will be evaluated (samples)
  • additional comments about experimental design


  • cite all sources
  • list all references alphabetically by author



1. Revision
Recall that a protocol is to be written in a simple, concise, and accurate style. For the following passages from a protocol, hints are given to prompt improvement. Rewrite each passage to make it clearer and more accurate (the proper style for a protocol's purpose).

1a. The purpose of this lab is to see what affects how beanstalks grow.

Wasted words?
This passage would appear under Purpose.)
Of the lab, or of the experiment?
Will the effects of numerous independent variables be examined?

1b. We will study the effects of light on plants.

Light has several characteristics. Will all be studied?
On all characteristics of plants, or a particular one?
On all plants, or a particular species?
1c. We will calculate the average growth rate for each light intensity.
Do light intensities grow?
1d. We will make a graph of beanstalk growth over time.
What will be on each axis?
To what does "growth" refer (height, weight, cross-sectional diameter)?
Will there be a curve for every plant? (Consider means.)
1e. If such graphs show similar trends, the null hypothesis is supported, and it can be concluded that light intensity does not affect beanstalk growth.
Ever? A more subtle problem here: Consider the time period for which measurements will be made. A simple, qualifying phrase can be added to the end of this statement to improve its accuracy.

2. Simplification and Clarification via Tables

Recall that data acquisition tables serve to simplify Materials and Methods sections because they can be referred to with a minimum of words. At the same time, such tables clarify for readers precisely what data will be obtained and how it will be organized. The following example appeared under Data Presentation above:

Measure the heights of 12 beanstalks - 4 beanstalks at each light intensity of 1, 3, and 5 kW/m2, and take measurements 3 times on each plant 4, 8, and 12 days after they germinate, for a total of 36 measurements.
This procedure, as it is described, is potentially confusing. Notice that more than one plant will be exposed to each light intensity. Each plant in a group exposed to identical conditions is referred to as a replicate, so there are 4 replicates at each light intensity. The growth characteristics of 4 different plants are unlikely to be identical because variability among living organisms is the norm, but a mean can be used more generally to represent beanstalk growth at a particular light intensity.)

2a. Construct a blank data acquisition table for this procedure, and appropriately incorporate a position where replicate means (actually analyzed data) will be indicated. Include clear and accurate column headings and units (if necessary, review the TABLES AND FIGURES section under FORMAT in Chapter 1).

2b. Write a sentence or two, as it would appear in a Materials and Methods section, that refers to the table in describing the procedure.

2c. In anticipation of graphing, prepare blank analyzed data tables (perhaps one for each light intensity). Indicate where values will be recorded that correspond to x- and to y-axis coordinates.

2d. Again, write a sentence or two, as it would appear in a Data Presentation section, that refers to the tables in 2c. to describe how the raw data will be converted to analyzed data to fill the tables.

3. Information Provided by Graphs.
Composing an effective protocol requires that it be thought through entirely. If the experimenters propose to construct graphs, the value of graphical information has to be appreciated even though numerical data has not yet been collected. The graphs here appeared under Data Presentation above.

3a. In this chapter's example of beanstalk growth, light intensity has been described as the independent variable. Explain, then, why time appears on the x-axis of the graphs. (Recall what information is typically plotted on the x-axis.)

3b. What is a rate? What feature(s) of these graphs indicate growth rates? Are the growth rates at any of these light intensities constant over 12 days? Would average growth rates be useful to assess the hypothesis in this experiment? Why, or why not?

3c. If these two graphs were obtained as actual results, the null hypothesis that light intensity does not affect beanstalk growth could not be easily evaluated. However, results that would lead to rejection of the null hypothesis were considered in the following passage from Data Presentation:

The null hypothesis is rejected if the curves show the trend that more and faster growth occurs at higher light intensities. In other words, light intensity does appear to affect growth. The same conclusion would apply if the trend were reversed (lower intensities, more and faster growth).
Sketch the 2 sample graphs that conform to the 2 trends described.




A reader cannot ask an author for any more explanation than that provided. Writing conventions evolve so that the written word is clear to all readers of the language, regardless of how each individual would speak. In other words, writing conventions are indeed reading conventions. Consequently, unconventional writing runs the risk of being unfamiliar, unclear, or ununderstood. Here is a common response to criticisms on grammar or usage: "The point is to communicate. If you understood what I meant, why is it so important that I follow picky rules?" The point of a scientific document is frequently to inform accurately and concisely. If readers must, in their own minds, think twice to interpret what you wrote, you failed to achieve the objective.

The degree to which your personal style is unconventional is likely to determine how much readers stumble over your writing. Departures from convention should require no clarification and should easily fit and work in the context:

Only the writer whose ear is reliable is in a position to use bad grammar deliberately... only he is able to sustain his work at the level of good taste. [Strunk and White, 1979, p.77]
Such judgment may be difficult because you must read your own writing as if it were someone else's. So, if you are not sure your departure from convention will be readily acceptable to your readers, use the convention!



Never start a sentence with a number without spelling it out.

Periods and commas almost always go inside quotation marks when they come after a word, phrase, clause, or sentence. Other punctuation goes outside, unless it is part of a quoted passage.

The correct use of commas (and there is indeed such a thing) in English is not a simple topic. Many writing manuals explain their proper use (see references below). Do not rely on others to point out incorrect uses of commas; all writers must be responsible enough to learn these proper uses themselves. It is surprisingly easy for educated writers, and even moderately experienced readers, to stumble over the incorrect use of commas. The foolish rule, "Wherever pauses seem appropriate, commas are used," is dismally misguided far more often than it is useful. The only answer is a combination of frequent reviews of the rules and continuous self-inspection.

Semicolons, colons, and dashes have very precise and different uses in English. They are not interchangeable. As with commas, their misuse is glaringly obvious to educated readers; learn their proper uses.

Avoid using contractions (words such as you're, it's, don't) in writing, unless they are part of a quoted passage.

Avoid incorrect pronoun-antecedent agreement.
If you love someone, set them free. Them cannot refer to a someone.

Avoid split infinitives.
We want to better understand. Instead use: We want to understand better.

Avoid dangling modifiers.
Being albinos, we could easily pick out the mutant flies. Instead use: We could easily pick out the mutant flies because they were albinos.
I wrote a paper on Charles Darwin in English class.
Instead use: In English class, I wrote a paper on Charles Darwin.

Avoid incorrect subject/verb agreement.
Each of the flasks are full. (Use: Each.. is full.)
Either Ken or Kim are going.
(Use: Either [one].. is going.



The words below are followed by examples of correct usage. Space is left for you to add your own common errors and style problems.

Instructors will accept any paper, except late ones.

A drug causes an effect. Your health is affected by the effects of toxins.
Typically, affect is a verb meaning to influence, and effect is a noun.

all ready/already
Mixtures are prepared already. They are all ready.

A juror was sick. As an alternative to postponing the trial, we used an alternate.

There was agreement between each of the three leaders, but civil wars continue among people within each nation.

We did it as our teacher showed us. Avoid words like ain't.
is not a substitute for as. If anything but a noun or pronoun follows like, it is wrong.

Besides his ring, he keeps his wallet beside the lamp.

Cells comprise organelles; organelles do not comprise cells.
means to include or to contain; avoid comprised of.

She is on her way and will be here presently. He has arrived and is currently awaiting her.
never means in a short while. Presently can mean currently, but why be ambiguous?

We walked farther. We read further in the manual.
Farther is for distance; further is for degree or extent.

We have fewer pennies, so we have less money.
refers to countable number; less refers to quantity.

The results imply that wood burns. From these results, we infer that wood bums.
means to suggest, to indicate; infer means to interpret, to deduce; a speaker implies, but a listener infers.

It's not in its nature for a stem to grow downward.
always means it is.

Let me go. Leave me alone. Let it remain. Let him leave.

The people inside... The six persons inside...
Use persons when they are numbered. "If of six people five went away, how many people would be left? Answer: one people." [Strunk and White, 1979, p.56]

We placed the square and round pegs in their respective holes. We placed round and cube pegs in the circular and square holes, respectively.
Try to avoid using respectively; it is awkward for readers.

If you leave, then turn out the lights. This is greater than that. If one is heavier than the other, then there is more in it.

The measurement that we made... (indicates which measurement)
The measurement, which we made,... (incidental addition)
That is called the restrictive pronoun - it restricts the meaning of the measurement from just any measurement; it introduces an essential clause. Which is nonrestrictive, and the clause it introduces is nonessential - it just adds information.

There are ways to get their attention; there's always a way. Is it yours or theirs? They're not paying attention.
means they are; there's means there is.

We are going too. We are going to class. It takes too long to get to class.

If your writing is poor, then you're not going to be too effective at communicating your message.
means you are.


Poor/incorrect wording choice

prove a hypothesis
alls you got to do
at this point in time
due to
due to the fact that
different than
make one thing perfectly clear
the majority of
needless to say
one of the most
on a daily basis
on account of
pooled together
very unique
referred to as
take into consideration
the reason is because
the reason why is
the question as to whether
the fact that
we believe, I feel
try and, be sure and
eg., ie., etc
as yet
regarded as being
based on the fact that
the fact of the matter is
deal with


support a hypothesis
all you have to do
then, now, next
because of
different from
avoid after "e.g.,"
a snow job is coming
avoid (and omit what follows)
called, termed
the reason is that

try to, be sure to
e.g., i.e., etc.
regarded as

Singular, plural

analysis, analyses
bacterium, bacteria
cilium, cilia
criterion, criteria
flagellum, flagella
fungus, fungi
genus, genera
hypothesis, hypotheses
mitochondrion, mitochondria
nucleus, nuclei
phenomenon, phenomena
phylum, phyla
radius, radii
species, species
stoma, stomata
taxon, taxa

The following assemblies of letters and punctuation are not accepted as English. Correct terms are provided in parentheses.

alot (avoid)
alright (all right)
complected (has a dark or light or fair complexion)
expediate (expedite)
her's (hers)
irregardless (regardless)
orientated (oriented)
our's (ours)
their's (theirs)
your's (yours)




A Manual of Style, 12th Edition. 1969. The University of Chicago Press.

Schali, J. 1991. Writing Manual for Students. College of Earth and Mineral Sciences, Pennsylvania State University.

Shertzer, M. 1986 The Elements of Grammar. Collier Books, Macmillan Publishing Company. New York.

Strunk, W., Jr., and White, E., B. 1979. The Elements of Style. Macmillan Publishing Co., Inc. New York.


American Society for Microbiology. 1991. ASM Style Manual for Journals and Books. ASM, Washington DC.

Booth,V. 1993. Communicating in Science: Writing a Scientific Paper and Speaking at Scientific Meetings. Cambridge University Press, Cambridge.

Gubanich, A. A. 1985. A Student's Guide to Writing a Scientific Paper: How to Survive the Laboratory Research Report. Kendall/Hunt Publishing Co., Dubuque, IW.

Lobban, C. S., and M. Schefter. 1992. Successful Lab Reports: A Manual for Science Students. Cambridge University Press.