Hypothesis Activity

Opinion
For every opinion, belief, or point of view, there is someone who holds a different opinion, belief, or point of view. We constantly have to decide which opinion is correct and, subsequently, what course of action to follow: what to buy, how to vote, where to spend our time. Making a good decision requires knowing the choices, having valid information, and making a judgment. We will learn how to make decisions by using hypotheses and practice the skill in class.

What is the Point
A person often expresses belief as a fact that assumes proof and justifies a conclusion. In spite of the complexity of the belief, we can identify the points both made and implied by the statement and examine each individually. We will pick one of the points and treat it as a hypothesis, that is, a statement or explanation. Next, we will write an alternative hypothesis to represent a contrasting belief. One of these hypotheses will express the condition without an effect or a change or a difference, and we will call it the "null" hypothesis (null=no effect, no change, no difference). Then we will describe the information we need to decide which belief is true or cite relevant evidence.

Example:

Statement
Suppose that the hypothesis statement for the week is, "Global temperatures have never been so warm as they are today because the atmospheric concentration of carbon dioxide has never been as high as now and there were no sources of fossil fuels until recently."

Points
This statement expresses three points: 1) global temperatures now are the highest they have ever been on Earth; 2) atmospheric carbon dioxide is higher now than ever in the history of the planet; and, 3) the implication that large amounts of carbon dioxide come only from fossil fuels. There is a priority among these points in the order in which they are stated. That is, high global temperatures are caused by large amounts of carbon dioxide which has its only source in fossil fuels.

Hypotheses
Write a null hypothesis for only one of the points and a reasonable contrasting alternative. Such a null hypothesis might be that, "Global temperatures are no higher today than during other times in Earth's history." It is the null hypothesis because it states that temperatures have not been different at some other time. Notice that the statement says that the temperature is higher now, but the null hypotheses states that is not. We start with the hypothesis that the factor (temperature) was not (=null) different and then set out to reject that null hypothesis.

A reasonable alternative for this null hypothesis would be that, "Temperature has been higher in the past." If the alternative hypothesis is reasonable, then you should feel comfortable in accepting its conclusion if you obtain enough evidence to reject the null hypothesis. Other possible null hypotheses consistent with the statement are, "Atmospheric carbon dioxide is no higher now than at times in the past," or "There are various sources of carbon dioxide on the Earth."

Evidence
To discriminate between the null hypothesis and its alternative, we would need a long-term record of global temperature on our planet. Collect evidence that could reject the null hypothesis. (There is only one set of evidence since you are attempting to reject the null hypothesis, not prove each hypothesis separately.) Such evidence could include historical records of temperatures, inferences from ice core samples from Antarctica, or inferences from sediment cores.

Complications
There is a temptation to elaborate hypotheses to include additional ideas. For instance, "The industrial revolution initiated the impetus for large sources of fuel." Complicating your hypothesis makes it difficult to test the fundamental point that global temperatures are rising. Keep the hypothesis simple, test it, and, on the basis of the results of your first test, consider testing any of the other ideas with its own pair of hypotheses.

Confounding Factors
Besides the factor you are specifically testing, there may be other factors that influence the data and those factors needed to be eliminated, controlled, or adjusted for.

Submitting Hypotheses and Description of Evidence

The Hypothesis Assignment
Click on the Assignment Tool (in the column of icons at the left of the class page). Then click on the name of the assignment for the week that starts with an "H" and the number of the week, e.g., H01 for week#1. Download the attached file and write your answers to each item in spaces provided. There is a link to a model of the exercise to follow. Click on the link, print the model, and refer to it as you complete the exercise.

Grade and Feedback
Probably more than any other activity in this class, regularly dissecting statements, writing hypotheses, and testing explanations will give you the opportunity to hone your critical reading and critical thinking skills. Whenever you do not earn the full 5 points on a week's class statement, we will provide you with comments specific to what you submitted to tell you what you should have done that week so that you can see how to do it correctly in the remaining weeks. Make a habit of checking the comments.

Tutorial
There are samples of the hypothesis activity embedded in the class web pages. The BIO 302 URLs web pages in each weekly module shows you where you can find them. Click on the link and examine all the available threads. Login with your last name and university ID number.

Each sample hypothesis activity is an online interactive tutorial that gives both correct and incorrect responses. They contain feedback for each response that shows you how to successfully complete each step and what mistakes to avoid. They contain feedback on the content of the hypothesis topic as well as the mechanics of how to approach each answer. The sample takes you through the entire set of steps exactly as they occur in the weekly hypothesis activities and is specifically designed for people who have never worked with hypotheses before.