(COC) Lab Report Lesson
Lab Report
Now that you have an understanding of the basic components of scientific investigations, how do you compile your investigations into a readable, reviewable document? You must create a lab report. For this course, you will be required to write a lab report for all of your labs. Please include the components below in each lab report:
- Introduction
- Methods
- Results
- Analysis
Let's break each down so that you know exactly what needs to be included in each portion of the lab report.
The Introduction needs to be at least a paragraph. It needs to include background knowledge of the topic that can include prior knowledge as well as research you have collected. You should also state your hypothesis and the reason why you are conducting the lab. The introduction paragraph should let readers know what you are hoping to learn by conducting the experiment.
The Methods section needs to include all the materials that you have used in the experiment as well as a detailed procedure. Providing a step-by-step explanation of how you conducted your experiment is important so that others know exactly what was done and can replicate the experiment if they choose. It is sometimes helpful to include drawings or diagrams to describe your procedure or lab setup. There will be times in which you will copy/paste the given lab procedures while there will be other times in which you will need to design your own experiment.
The Results section of the lab report needs to include your observations. Data tables with both qualitative and quantitative observations should be included. Pictures or drawings should be included to enhance the reader's understanding of your results as well. In addition to the data table, graphs should be included to summarize the findings.
The Analysis section should include both answers to the analysis questions and a conclusion paragraph. In the conclusion paragraph, you should include what you learned from doing the experiment if you accept or reject your hypothesis, and what you would do differently if you performed the experiment again. It is important to be very thorough in this section.
Scientific Theories and Scientific Laws
By reporting scientific findings, our knowledge of the world and how it works continues to grow. When a hypothesis is well supported through extensive and repeated testing, it becomes a scientific theory. This can be somewhat confusing in that our common, everyday language of the word theory means something that is untested or an idea or an opinion. However, scientific theories have been widely tested and yield the same results over and over again. A scientific theory remains valid as long as there is no evidence to disagree with it. Some examples of scientific theories include the Theory of Plate Tectonics, Atomic Theory, the Theory of Relativity, and the Theory of Evolution by Natural Selection.
It is important to understand that scientific theories are not scientific laws. Scientific laws are statements that describe patterns found in nature. Scientific laws do not attempt to explain why something is occurring. Scientific laws help to predict the behavior of objects. A scientific law simply says what happens; it does not address the question of why. One example of a law, the law of definite proportions, which was discovered by the French scientist Joseph Proust (1754-1826), states that a chemical substance always contains the same proportions of elements by mass. Thus sodium chloride (table salt) always contains the same proportion by mass of sodium to chlorine, in this case, 39.34% sodium and 60.66% chlorine by mass, and sucrose (table sugar) is always 42.11% carbon, 6.48% hydrogen, and 51.41% oxygen by mass. The law of definite proportions should seem obvious—we would expect the composition of sodium chloride to be consistent—but the head of the US Patent Office did not accept it as a fact until the early 20th century.
Theory vs. Law Activity
Chemistry Concepts
Scientists are continually trying to expand our current knowledge and to ensure the theories and laws accepted are correct and applicable. In the next couple of modules, we will be looking at introductory Chemistry concepts. Chemistry is the study of matter and the changes that material substances undergo. Examples of the practical applications of chemistry are everywhere. Engineers need to understand the chemical properties of the substances when designing biologically compatible implants for joint replacements or designing roads, bridges, buildings, and nuclear reactors that do not collapse because of weakened structural materials such as steel and cement. Archaeology and paleontology rely on chemical techniques to date bones and artifacts and identify their origins. Although law is not normally considered a field related to chemistry, forensic scientists use chemical methods to analyze blood, fibers, and other evidence as they investigate crimes. In particular, DNA matching—comparing biological samples of genetic material to see whether they could have come from the same person—has been used to solve many high-profile criminal cases as well as clear innocent people who have been wrongly accused or convicted. Forensics is a rapidly growing area of applied chemistry. Although most people do not recognize it, chemistry and chemical compounds are crucial ingredients in almost everything we eat, wear, and use.
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