finish worksheet and excel
Tutorial deliverable: Complete worksheet (below) and create a graph and insert it using the data provided (“student_data_guided”). Submit one file. NAME___________________________ Tutorial Bald Eagle long term dataset – read corresponding case study handout. Part I: How does the bald eagle population at a winter stopover change over three decades? 1.Look over the terms in the glossary and the proposal worksheet (see below). For example, what is the difference between the dependent variable versus the independent variable? Open the excel file with the data for the guided approach (posted on Moodle) and examine the data. Apply the terms from the glossary to the data in the excel file. Are the data continuous or categorical? 2. You already know the question we want to ask about bald eagle numbers over the last thirty years since the ban on DDT, so make a prediction. Do you think there are more migrating bald eagles at Lake Coeur d’Alene? Less? Will the numbers fluctuate over time? Why did you make this prediction? Your explanation for your prediction is your hypothesis. Some scientists will combine the prediction and hypothesis into one “If-then” hypothesis. The “if” clause contains the hypothesis and the “then” clause contains the prediction that is to be tested (see instructor provided examples). When making a hypothesis you are making assumptions for factors that will not vary with your treatments. For example, you are assuming that the eagles will migrate along a similar path each year. 3. To answer your question, you need to determine the data needed (i.e., experimental design). There are different types of experimental approaches, such as manipulative (you manipulate the independent variable and measure the dependent variable) and observational (you measure a response in nature, dependent variable, and nature provides the manipulation, independent variable). We are dealing with the latter situation. Complete the research proposal worksheet (see below), using your resources. 4. Graph the data from the provided excel file (posted on Moodle), using your proposal to assist you. What does your graph say or what is the pattern that your data shows? What does your graph mean or what is your interpretation of the data pattern? Was your prediction accurate? Do the data support your hypothesis? 5. Upload your COMPLETED worksheet below (include graph) in ONE FILE for tutorial weekly deliverable mark. Worksheet – Observational Experimentation Scientific process Bald eagle population over three decades Question: Prediction (then): Hypothesis (If): Assumptions: Experimental Design Independent variable(s): Dependent variable(s): Type of graph (line or bar): Insert the graph on the worksheet document and make sure it has labeled axes and a proper figure caption. Beckstead, J., A. N. Lagasse, and S. R. Robinson. February 2011, posting date. Exploring the population dynamics of wintering bald eagles through long-term data. Teaching Issues and Experiments in Ecology Vol.7: Data sets [online]. http://tiee.esa.org/vol/v7/issues/data_sets/beckstead/abstract.html GLOSSARY FOR THE SCIENTIFIC PROCESS Data – Small amount of information about the subject of an investigation. Continuous Data – Points taken along a scale that can be infinitely subdivided (think decimals). Time, weight, and temperature are examples. Also called ordinal data. Categorical Data – Each point falls into a non-numeric group or category, e.g., male or female. Also called nominal data. Discrete Data – Each point can be only a whole number. Cats would be discrete units because there is no possibility of a fraction of a cat. We count or tally these data. Experimental Design – The formal design worked out to test the prediction of a hypothesis. Independent Variable – The factor to be varied by direct manipulation by the investigator or by natural categorization in the experiment. It is expected to cause an effect in the dependent variable. In a graph this variable occurs on the x (horizontal) axis. Dependent Variable – The variable whose response we measure in the experiment. It is expected to result from variation in the independent variable. In a graph this variable occurs on the y (vertical) axis. It may be a continuous or discrete variable. Experimentation – Methods used to test predictions of hypotheses. Manipulation – Alterations in the independent variable are created by the investigator. Observation – Natural variation in the independent variable occurs, requiring no alteration, only direct observation of the dependent variable by the investigator. Graph (Figure) (Chart) – A diagram that represents the variation of a variable in comparison with that of one or more other variables. Axes – Horizontal (x axis, abscissa) for independent variable(s). Vertical (y axis, ordinate) for dependent variable(s). Caption – A short description accompanying the graph that includes some form of reference to the axes and sample size. Sometimes called a legend. Bar Graph – Used when the independent variable is categorical (otherwise known as Column Graph). Line Graph – Used when the x axis represents a continuous variable. Sometimes the x variable is the independent variable. Other times, as in showing a correlation, neither x nor y variables are designated as independent or dependent variables. Hypothesis – A formal statement of a possible explanation for an observed phenomenon. A “might-be” about the way the world works. It leads to predictions. Prediction – A consequence expected by the logic of the hypothesis and basis of the experimental design. If-then logic – A formal conditional statement of the hypothesis and prediction that uses deductive logic. If the phenomenon I observed can be explained in this way, then these consequences should occur. The “if” clause contains the hypothesis and the “then” clause contains the prediction that is to be tested. Assumption – A fact that is taken-for-granted in the experiment. If the experiment fails to falsify the hypothesis, the assumption may not have been true and they may need to be tested. 1 - 4 - TIEE Teaching Issues and Experiments in Ecology - Volume 7, February 2011 TIEE, Volume 7 © 2011 – Julie Beckstead, Alexandra N. Lagasse, and Scott R. Robinson, and the Ecological Society of America. Teaching Issues and Experiments in Ecology (TIEE) is a project of the Education and Human Resources Committee of the Ecological Society of America (http://tiee.esa.org). Instructions (Instructor will assign one of the approaches below): Guided approach: Part I: How does the bald eagle population at a winter stopover change over three decades? 1. Look over the terms in the glossary and the proposal worksheet (provided by your instructor). For example, what is the difference between the dependent variable versus the independent variable? Open the excel file with the data for the guided approach (provided by your instructor) and examine the data. Apply the terms from the glossary to the data in the excel file. Are the data continuous or categorical? 2. You already know the question we want to ask about bald eagle numbers over the last thirty years since the ban on DDT, so make a prediction. Do you think there are more migrating bald eagles at Lake Coeur d’Alene? Less? Will the numbers fluctuate over time? Why did you make this prediction? Your explanation for your prediction is your hypothesis. Some scientists will combine the prediction and hypothesis into one “If-then” hypothesis. The “if” clause contains the hypothesis and the “then” clause contains the prediction that is to be tested (see instructor provided examples). When making a hypothesis you are making assumptions for factors that will not vary with your treatments. For example, you are assuming that the eagles will migrate along a similar path each year. 3. To answer your question, you need to determine the data needed (i.e., experimental design). There are different types of experimental approaches, such as manipulative (you manipulate the independent variable and measure the dependent variable) and observational (you measure a response in nature, dependent variable, and nature provides the manipulation, independent variable). We are dealing with the latter situation. Complete the research proposal worksheet (provided by your instructor), using your resources. 4. Graph the data from the provided excel file (provided by your instructor), using your proposal to assist you. What does your graph say or what is the pattern that your data shows? What does your graph mean or what is your interpretation of the data pattern? Was your prediction accurate? Do the data support your hypothesis?