How to Write an Abstract/ Examples of Abstracts/

The Lab abstract should be no more than 200 words.  IN A CONCISE, CONVERSATIONAL,3rd person manner.  It is written in past tense and should catch the readers’ attention.  A person reading it...your teacher, a science fair judge, or your classmates should be able to easily understand what was going on as well as the outcome in the lab.   This is a summary of the basic content of the experiment. It should state the purpose of the experiment, mention the techniques used, report results obtained, and give conclusions. The point of the abstract is to give a concise summary of the whole report. The most common mistake that students make is not including summary data. Example:

Chromosomal DNA was successfully isolated from Bacillus subtilis strain 151 using a modification of the Marmur technique. Spectrophotometric analysis revealed some contamination with protein, but little RNA contamination. The pure DNA had a concentration of 1.05 mg/ml with a 10.3 mg total yield. The DNA was sterile, as judged by streaking onto penassay agar.




The whole report in miniature, minus specific details--
  • State main objectives. (What did you investigate? Why?)
  • Describe methods. (What did you do?)
  • Summarize the most important results. (What did you find out?)
  • State major conclusions and significance. (What do your results mean? So what?)
Do not include references to figures, tables, or sources.

Do not include information not in report.

Find out maximum length (may vary from 50 to 300+ words).

Process: Extract key points from each section. Condense in successive revisions.

For informal lab reports, I also require that you include a data table , and a graph of the data.  Line graph is generally used. Depending upon the lab, I will indicate which is most appropriate for that particular assignment.

Check these web sites for good information on lab abstracts.  (samples too)



When grading another person’s abstract,  ask yourself: 

1.    Do you know their hypothesis? Did they mention whether it was supported or not supported by their data?

2.    Do you know what this person did?  (generalization of procedure & materials)

3.    Do you know their results?

4.    Did they suggest another technique that could be used to get different results

5.    Does anything they said make you go "huh?" If so circle it. 


Yes to #1-4 and no to #5 = 5

Yes to three out of  #1-4 and no to #5 = 4

Yes to two out of #1-4 and yes to #5 = 3

Yes to one out of #1-4 and no to #5 = 3

Yes to one out of #1-4 and yes to #5 = 2

Yes to zero out of #1-4 and no to #5 = 1

No to everything = 0


Sample Abstracts

What is an Abstract?

Abstract (~250 words written AFTER the main report (but comes first in the document) it is intended to explain the objectives of the research, the hypothesis and null hypothesis, how the experiment was conducted, the findings of the experiment and finally the implications and conclusions of the experiment that must be able to suggest you support either your hypothesis or null hypothesis). A person grading the report would read this first and have the “big idea”.  THE ABSTRACT SHOULD BE ABLE TO "STAND ALONE"... meaning that if there are no other parts of the lab report available to read, then the reader will know briefly what you did in the experiment, and what happened.  The abstract is written single spaced, in a font smaller than the text for the body of the lab report, and the margins are justified.  Note:  The null hypothesis is a prediction of what would happen if the experimental treatment has no effect on the outcome.




What's Up Doc?

The purpose of this experiment was to demonstrate movement of water or sugar molecules into or out of cell membranes.  The sub-purpose was to determine how much sugar and water are in a carrot.  The hypothesis states that if carrots are placed in a varying amounts of sucrose solution then the mass of the carrots will change.  The null hypothesis states that if the carrots are placed in varying amounts of sucrose solution then the carrot mass will not change.  The carrots were peeled, sliced and massed before placing them in the beakers with various sucrose solutions ranging from 0%, 7%, 14%, 21% 28% and 35%.  After 24 hours of soaking the carrot slices were removed, briefly blotted to remove solution clinging to the outsides, and re-massed.  The carrots in the 0% sucrose solution gained .4 gms, in 7% solution gained .1 gms, in 14% solution lost .2 gms, in 21% solution lost .42 gms, in 28% solution lost .52 gms and in 35% solution lost .66 gms.  It can be concluded that the hypothesis was supported and that the carrots that gained weight have a sucrose % greater than the solution in which they were soaking, making them hypertonic to the solution, whereas the carrots that lost mass were hypotonic to the solution in which they were soaking; therefore have less sucrose than the solution. 

How Fast Sow Bugs Travel

Informal Lab Report – Arthropod Inquiry Lab


        The goal of the lab was to calculate the speed of sow bugs.  The hypothesis stated that if the sow bug is allowed to travel at an uninterrupted pace then the speed of the sow bug can be calculated at about one half a mile per hour. The null hypothesis is that the sow bug’s speed cannot be calculated because it is not a constant speed.  To figure out the speed of the sow bug, the bug was placed on a grooved ruler with a sheet of clear plastic over the top to prevent the bugs escape.  The bug was then timed on how long it took it to travel the length of the ruler using a stopwatch.  This procedure was repeated ten times to get the most accurate results.  The data was then converted to miles per hour (m.p.h.) and the average speed was calculated.  The average time it took the sow bug to travel 12 inches was 14.513 seconds, or an average of 0.109 miles per hour.  This is extremely slow.  The data does not support the hypothesis, but rather supports the null hypothesis.  It was learned, though, how fast a sow bug travels, which was the objective of the lab.  It can be concluded from this lab that it would take a sow bug a very long time to travel one mile.



Green Advice

Testing pH with Plant Pigments


            The purpose of this investigation was to determine which types of plants and their parts could be used as pH indicators.  It was hypothesized that if the pigmentation of a purple azalea flower petals was subjected to different standardized pH solutions, then the petal’s pigment would turn different colors depending upon the pH of the solution being tested.  The null hypothesis is that the plant’s parts will not respond to any of the standardized pH solutions.  The pH 1-14 standards were produced by a serial dilution using two starting pH solutions of 1 and 14 and distilled water.  The azalea petals were soaked in isopropyl alcohol to extract any visible pigment.  Using a spot plate, each pH standard was placed in a numbered spot and two drops of the azalea petal extract was added.  The resulting colors were recorded ranging from light pink in a pH 1 spot to a deep blue in a pH 14 spot.  To determine the validity of the pH test, each of the pH standard spots were tested with pH paper.   Since the colors changed, when the flower petal pigments were subjected to each of the different pH standard solutions, the hypothesis was supported by the data. 


Green Advice

Testing pH with Plant Pigments



        This experiment uses plant pigments and tests them to see if they are good pH indicators.  The hypothesis was that if a carrots pigment were removed and tested with a range of pH solutions, then it would prove to be a good pH indicatorThe null hypothesis is that the carrot pigment will remain unchanged when tested with the various pH solutions, therefore indicating that the carrot’s pigments are not good pH indicators.  Isopropyl alcohol was used to extract pigment from two grams of ground up carrot.  The pigment was yellow.  Then, using 14 numbered test tubes; 9ml of distilled water was put in all test tubes except one and 14.  In number one,               10ml of HCl was put in, and 10 ml of NaOH was put in number 14.  Then a serial dilution was performed going from one to six and then 14 to 8.  This provided pH solutions ranging from a pH of one to a pH of 14.  Then a spot plate was numbered and a few drops from each numbered test tube were put in the corresponding spot on the spot plate.  Next, a few drops of the carrot pigment were placed in each spot of the spot plate.  The color change was then observed.  This experiment supported the null hypothesis because the experiment showed that a carrot is not a good pH indicator.  All of the solutions in each spot plate remained yellow.


Lab Writing Prompts

Lab Writing Prompts

Guiding Prompts for a great Lab Report

**You will be assigned to write either a Formal or an Informal lab report.  ALL of the following PARTS must appear in a formal lab report. *An asterisk indicates the prompts that must appear in a Informal lab report. 

*Title:  Does the title describe clearly and precisely what you investigated? 

*Question:  Is the question clearly stated in a manner that your abstract will support?

*Abstract:  Within this paragraph is the question, purpose and hypothesis/null hypothesis stated?  Does the abstract explain why we did this experiment?  Does the abstract state the problem.  Did you clearly describe what you intended to investigate?  Does it summarize the methods? Did you state what factors were varied and how they were varied?  Did you summarize what measurements you took and how you took them?  Did you describe the controls?  Did you use past tense (third person) <see bottom of page>  narrative in writing this section and summarize the results and conclusions in 200- 250 words?  Is all of this information given in a logical order and succinct manner? Is it it interesting and clear?   

Purpose/Introduction:  Is the purpose of the lab clearly stated? Is a statement of how the problem arose included?

Hypothesis:  Is the hypothesis written in an investigative format (cause and effect)?  Is it written in an If, (independent variable) then, (dependent variable) form? Did you write a null hypothesis?  The null hypothesis is often the reverse of what the experimenter actually believes; it is put forward to allow the data to contradict it. Depending on the data, the null hypothesis either will or will not be rejected as a viable possibility.

Materials:  Did you list all materials, specimens, chemicals & equipment used?  Did you include amounts of materials, chemicals etc.?

Procedure:  Did you give a complete account of the methods used in gathering the data?   

*Results:  Did you include:

*Data Tables:  Tables have a table number and a descriptive title. All of the columns are labeled with units of measure.  The independent variable (or variables) is placed on the left.  The dependent variable (or variables) should be placed to the right.  

Are they thorough and organized?  Did you give detailed observations?  {See Helms Appendix 1 Part A handout }


Table 1  Growth Rate of Marigold seedlings without added fertilizer . Control Group

Time (days)

Height (cm)









* Graphs:  Do you use a Line or Bar graph? 

 Did you include correctly labeled (X= (independent variable) /Y= (dependent variable) and units = e.g. cm, mm etc...)? 

Discussion : This section demonstrates the relationship between data and the purpose. Did you analyze the results such as:  determine rate, or mean,  or standard deviation, etc...? {see Helms Appendix 1 Part B handout} Did you  point out anomalies in your results?  Did you refer to your table and/or graph in your explanation?  Did you avoid the words "proved, proves or wrong and right" , instead use "supports the hypothesis or supports the null hypothesis"?

*Conclusion:  Did you restate your hypothesis?  Did you clearly state whether or not you were able to answer the questions you asked?  Did you state whether or not your hypothesis was supported and if not, suggest reasons? Did you explain what the results mean, rather than simply restating or listing them? Did you suggest further relevant experiments, if applicable?  Did you check that it is clearly written and proceeds in a logical order?  Did you arrive at a conclusion based on observations and scientific concepts?  Did you use evidence from your data to support your conclusion?   

Diagrams: Are the illustrations, or photos neatly reproduced and clearly labeled?

Mechanics:  Is your grammar correct throughout the report?  Is spelling correct throughout the report?  Is punctuation correct throughout the report?  Is your writing style interesting and engaging throughout the report?

***Third Person Writing***

Point of View – The point of view refers to whoever is telling the story or “speaking.” When you write a letter you are writing in “first person” which includes I, me, my, we and our. Second person writing occurs when we talk about you and yours and third person includes he, she, they and theirs. In third person writing, the author does not interject himself into the story. In writing third person (contrary to how you are currently encouraged to write for your language arts classes), think about "newspaper articles...they for the most part are written in third person.

Third person is hard to write.  It sounds so "impersonal and professional", but that is what makes a good abstract.