LabWrite Glossary

abstract: The Abstract is a miniature version of the whole lab report. Each major section of the lab report is summarized in the abstract - Introduction, Materials and Methods, Results, Discussion, and Conclusion - in 1 sentence each (two if a section is complex). The summaries are strung together in a paragraph in the order the sections come in the final report.

accuracy: Accuracy refers to the closeness of a measured value to a standard or known value. For example, if in lab you obtain a weight measurement of 3.2 kg for a given substance, but the actual or known weight is 10 kg, then your measurement is not accurate. In this case, your measurement is not close to the known value. Accuracy is independent of precision. You can be accurate, but imprecise.

appendix: An appendix is a place where you put information that does not deserve to be included in the report itself but may be helpful to some readers who want to know more about the details.

citation: A citation tells readers the source for information you have included in your writing, such as your textbook, the lab manual, a reference book or an article published in a journal. A citation should guide readers to the References where the readers can find the full bibliographical information on the source.

conclusion: The Conclusion returns to the larger purpose of the lab, which is presented as the learning context in the Introduction: to learn something about the scientific concept that provides the reason for doing the lab. This is where you demonstrate that you have indeed learned something by stating what it is you have learned. This is important because it helps you to understand the value of the lab and convinces the reader that the lab has been a success. It's important, then, to be specific, providing details of what you have learned about the theory or principle or procedure at the center of the lab.

control group: A Control group(s) is used as a baseline measure. The control group is identical to all other items or subjects that you are examining with the exception that it does not receive the treatment or the experimental manipulation that all other items or subjects receive.

Data: See qualitative data and quantitative data

dependent variable: A dependent variable (also known as the response variable), is what you measure in the experiment and what is affected during the experiment. The dependent variable responds to the independent variable. It is called dependent because it "depends" on the independent variable. In a scientific experiment, you cannot have a dependent variable without an independent variable.

discussion: The purpose of the Discussion is to interpret your results, that is, to explain, analyze, and compare them. The Discussion states whether or not the results from the lab procedure fully support the hypothesis, do not support the hypothesis, or support the hypothesis but with certain exceptions. Specific data-direct evidence from the lab- that either support or reject the hypothesis is identified in paragraph form. Outcomes from results are used to identify the particular data that led to the judgment about the hypothesis. This is the point at which the researcher stands back from the results and talks about them within the broader context set forth in the Introduction. It is perhaps the most important part of the report because it is where you demonstrate that you understand the experiment beyond the level of simply doing it. Do not discuss any outcomes not presented in the Results.

finding: A finding is the outcome of a research procedure, literally what was found. It can be represented in visual form (graph or table) or in words. General findings for each visual are determined in one of two different ways: as a summary of all the information in the visual or as a statement that focuses on the most important point that is made in the visual (important, that is, in terms of the hypothesis).

graph: A graph is a visual representation of data that displays the relationship among variables, usually cast along x and y axes. Graphs are especially useful in showing the broader trends in the data.

hypothesis: A hypothesis is a scientist's best estimation, based on scientific knowledge and assumptions, of the results of an experiment. It usually describes the anticipated relationship among variables in an experiment. The anticipated relationship between the dependent and independent variables is the result you expect when one variable reacts with another. A hypothesis typically leads to the crucial questions that must be addressed in the lab: did you find what you expected to find? Why or why not? The point of an experiment is to test the hypothesis.

independent variable: The value(s) you are manipulating is called the independent variable (also known as the “manipulated variable”). An independent variable is the variable you have control over, what you can choose and manipulate. It is what you predict will affect the dependent variable. In some cases, you may not be able to manipulate the independent variable. The independent variable may be something that is already there and is fixed, or something you would like to evaluate with respect to how it affects something else, the dependent variable: like color, kind and time.

inquiry: Inquiry is the act of asking questions and seeking answers to those questions. It is fundamental to the process of science.

introduction: The purpose of the Introduction is to establish a context for the rest of the lab report, and to establish the purpose for doing the experiment that is to be reported. Written in present tense, the opening one or two paragraphs clearly states the scientific concept and contains information about the concept that is most clearly related to the lab procedure. When scientists do research, the main purpose that guides their work is to contribute to the knowledge of their field. That's why the scientific context they establish in their introductions usually consists of summarizing previous research reports published in the field. A scientific contribution to the knowledge of the field can be understood only within the context of what other scientists have done. An effective introduction to a lab report typically performs the following tasks, generally in the order presented: (1) it establishes the learning context for the lab; (2) it provides the primary goals of the lab; (3) it offers a hypothesis for the experimental procedure.

lab notebook: A lab notebook, kept by professional scientists and engineers, are permanent legal records of all work conducted in the laboratory. Professional lab notebooks are: logs or journals of all the information collected during lab, including procedures and sketches of instruments or tools, written in ink with corrections initialed and noted, labeled with page numbers, time, date, and titles for all procedures, tables, charts, graphs, drawings, etc.

lab report: The lab report is written by students in laboratory courses to explore a scientific concept. Its primary purpose is to help students learn something about science.

learning context: The learning context situates the lab report within the overall purpose for doing the lab in the first place: to learn something about a particular topic within the scientific field you are studying. When scientists do research, the main purpose that guides their research is to contribute to the knowledge of their field. That's not typically the main purpose of a lab report, of course; rather, the main purpose is to provide you an opportunity for learning. That's why it's important to establish that learning context.

materials and methods: Materials and Methods takes the reader step by step through the laboratory procedure that the experimenters followed. The rule of thumb in constructing this section is to provide enough detail so that someone else can repeat the procedure.

multiple variables: An experiment in which you have multiple variables may have more than one dependent variable and/or independent variable. This is common in experiments with multiple stages or sets of procedures. In these experiments, there may be more than one set of measurements with different variables.

objective: The objective(s) provides the narrow focus for the lab. That means that you are supposed to concentrate very specifically on what it is you are supposed to accomplish in the experimental procedure itself. The objective(s) are actions, be sure to list them as such, to measure, to analyze, to determine, to test, etc.

parts of the lab report: The parts of the lab report, in the correct order for presentation, are: (1) Title, (2) Abstract, (3) Introduction, (4) Materials and Methods, (5) Results, (6) Discussion, (7) Conclusion, (8) References.

precision: Precision refers to the closeness of two or more measurements to each other. If you weigh 10 kg substance five times, and get 3.2 kg each time, then your measurement is very precise, but not accurate. Precision is independent of accuracy. You can be very precise but inaccurate.

procedure: For experimental procedure see Materials and Methods

purpose: The purpose of the lab is to learn how the objective will help you learn about the lab’s scientific concept. It is the all-important link between what you are doing and what you are learning. The purpose is what you will learn about the concept after completing the lab.

qualitative data: Qualitative data are data for which the scale of measurement is a set of unordered categories called a nominal scale. For example, types of trees, types of compounds, etc. Qualitative variables are considered discrete variables, because they vary in some quality but not magnitude--one category is not greater than the other.

quantitative data: Quantitative data are data for which the scale of measurement has magnitude and is either interval or ordinal. Quantitative values are continuous, so each possible value may be greater or less than any other value. Ordinal data has an order but the distance between values does not have precise numerical meaning. For example, rank in a graduating class or ranking of runners in a race. Interval data uses a scale that has a specific numeric distance between values—it has a unit of measurement. For example, the time which the runners ran the race is interval data.

reasoning: Reasoning is the logic used in going from initial understanding of the scientific concept to formulating a prediction of the outcomes of the experimental procedure. The hypothesis is a prediction of the outcome of the lab based on the initial understanding of the scientific concept of the lab. That understanding shapes the prediction of how the lab experiment will turn out and the anticipated relationship among variables.

references: The References section is a bibliography consisting of a list of the sources used in writing the lab report, such as the lab manual, textbook, a course packet, or a scientific article. It is similar to the Works Cited in papers for other classes. Generally speaking, more advanced labs and introductory labs for majors require References. Different scientific fields use somewhat different styles for documenting sources in the References. For example, in chemistry the American Chemical Society (ACS) style is used. In biology, it is the Council of Biological Editors (CBE) style. The style that is appropriate to the lab class is used.

relationship between variables: The anticipated relationship between the dependent and independent variables is the result you expect to get when one variable reacts with another. Since dependent variables "depend" on independent variables, there has to be a relationship between the two. In science, relationships between variables are usually shown in graphs. The independent variable is plotted along the horizontal or x-axis and the dependent variable along the vertical y-axis. In a table, usually the independent variable(s) is recorded in the first column, and the dependent variable(s) is recorded in the subsequent column(s).

research question: A research question acts as the guiding force behind the experiment. It is the broad question that the experiment is supposed to answer. The research question poses the problem of the relationship between the objective(s) and the purpose, between the specific experimental procedure and why you are doing that procedure in the first place.

results: This is the heart of the scientific paper, in which the researcher reports the outcomes of the experiment. Report is a key word here, because Results should not contain any explanations of the experimental findings or in any other way interpret or draw conclusions about the data. Results should stick to the facts as they have been observed. The Results section typically consists of both visual representations of data (tables and graphs and other figures) and written descriptions of the data.

scientific article: The scientific article is similar in format to the lab report, but it is written by professional scientists in order to relate findings of new science to the scientific community and to contribute to the knowledge available in a particular field of study.

Scientific concept: The scientific concept is the scientific theory, principal or law that is the basis of your lab. It is an explanation of why and how a specific natural phenomenon occurs or a logical, mathematical statement describing the consistency that applies to the phenomenon.

scientific law: A logical, mathematical statement describing a consistency that applies to all members of a broad class of phenomena when specific conditions are met. Examples of scientific laws: Faraday’s Law of electromagnetic induction, Coulomb’s Law of electrostatic attraction, Dalton’s Law of partial pressures, Boyle’s Gas Law.

scientific method: A process that is the basis for scientific inquiry. The scientific method follows a series of steps: (1) identify a problem you would like to solve, (2) formulate a hypothesis, (3) test the hypothesis, (4) collect and analyze the data, (5) make conclusions.

scientific theory: An explanation of why and how a specific natural phenomenon occurs. A lot of hypotheses are based on theories. In turn, theories may be redefined as new hypotheses are tested. Examples of theories: Newton’s Theory of Gravitation, Darwin’s Theory of Evolution, Mendel’s theory of Inheritance, Einstein’s Theory of Relativity.

sources of uncertainty (also called Sources of Error): In science, sources of uncertainty are potential problems with materials, instrumentation, and protocol that could lead to results that are questionable. Sources of uncertainty, often referred to as “sources of error,” can stem from any activity in the lab, from setting up the lab to analyzing data, and they can vary from lab to lab. Sources of uncertainty can be classified as random—those that cannot be predicted—or as systematic—those that are personal, procedural, or instrumental in nature.

treatment group: The treatment group is the item or subject which is manipulated during an experiment.

types of data: see qualitative and quantitative data

unit of measure: A standard of basic quantity or increment by which something is divided, counted, or described, such as ml, kg, mm, m/s, °F, etc.

variable: A variable is what is measured or manipulated in an experiment. Variables provide the means by which scientists structure their observations.

visualizing the data: The visuals tell the main story of the data. Visualizing the data means to represent data in the appropriate visual format for the lab report so that trends and relationships between variables are clearly identified. The type of data, quantitative or qualitative, and the relationships that may exist between variables will determine if the data should be represented as a table or a graph to summarize findings.





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