A scientific hypothesis is a tentative, testable explanation for a phenomenon in the natural world. It's the initial building block in the scientific method. Many describe it as an "educated guess" based on prior knowledge and observation. While this is true, a hypothesis is more informed than a guess. While an "educated guess" suggests a random prediction based on a person's expertise, developing a hypothesis requires active observation and background research. Show
Hypothesis basicsThe basic idea of a hypothesis is that there is no predetermined outcome. For a solution to be termed a scientific hypothesis, it has to be an idea that can be supported or refuted through carefully crafted experimentation or observation. This concept, called falsifiability and testability, was advanced in the mid-20th century by Austrian-British philosopher Karl Popper in his famous book "The Logic of Scientific Discovery" (Routledge, 1959). A key function of a hypothesis is to derive predictions about the results of future experiments and then perform those experiments to see whether they support the predictions. A hypothesis is usually written in the form of an if-then statement, which gives a possibility (if) and explains what may happen because of the possibility (then). The statement could also include "may," according to California State University, Bakersfield (opens in new tab). Here are some examples of hypothesis statements:
What makes a hypothesis testable?A useful hypothesis should be testable and falsifiable. That means that it should be possible to prove it wrong. A theory that can't be proved wrong is nonscientific, according to Karl Popper's 1963 book "Conjectures and Refutations (opens in new tab)." An example of an untestable statement is, "Dogs are better than cats." That's because the definition of "better" is vague and subjective. However, an untestable statement can be reworded to make it testable. For example, the previous statement could be changed to this: "Owning a dog is associated with higher levels of physical fitness than owning a cat." With this statement, the researcher can take measures of physical fitness from dog and cat owners and compare the two. Types of scientific hypotheses In an experiment, researchers generally state their hypotheses in two ways. The null hypothesis predicts that there will be no relationship between the variables tested, or no difference between the experimental groups. The alternative hypothesis predicts the opposite: that there will be a difference between the experimental groups. This is usually the hypothesis scientists are most interested in, according to the University of Miami (opens in new tab). For example, a null hypothesis might state, "There will be no difference in the rate of muscle growth between people who take a protein supplement and people who don't." The alternative hypothesis would state, "There will be a difference in the rate of muscle growth between people who take a protein supplement and people who don't." If the results of the experiment show a relationship between the variables, then the null hypothesis has been rejected in favor of the alternative hypothesis, according to the book "Research Methods in Psychology (opens in new tab)" (BCcampus, 2015). There are other ways to describe an alternative hypothesis. The alternative hypothesis above does not specify a direction of the effect, only that there will be a difference between the two groups. That type of prediction is called a two-tailed hypothesis. If a hypothesis specifies a certain direction — for example, that people who take a protein supplement will gain more muscle than people who don't — it is called a one-tailed hypothesis, according to William M. K. Trochim (opens in new tab), a professor of Policy Analysis and Management at Cornell University. Sometimes, errors take place during an experiment. These errors can happen in one of two ways. A type I error is when the null hypothesis is rejected when it is true. This is also known as a false positive. A type II error occurs when the null hypothesis is not rejected when it is false. This is also known as a false negative, according to the University of California, Berkeley, "Science at multiple levels" https://undsci.berkeley.edu/article/0_0_0/howscienceworks_19 Which of these is typically used to test a hypothesis?Experiments and further observations are often used to test the hypotheses. A scientific experiment is a carefully organized procedure in which the scientist intervenes in a system to change something, then observes the result of the change.
What experiment did the researchers conduct to test their hypothesis about the coat Colour in Himalayan rabbits?Ice Turns Himalayan Rabbits Black
Since the ears and feet of a Himalayan rabbit are colder they are generally black in color. In a classic genetics experiment a Himalayan is shaved and then an ice pack is placed on its back. The fur grows back black in the location that was cooled.
Which of these is typically used to test a hypothesis quizlet?An experiment is scientific testing. Experiments are designed to test hypotheses.
What process do scientists use to ask and answer questions about nature?Biologists and other scientists use the scientific method to ask questions about the natural world. The scientific method begins with an observation, which leads the scientist to ask a question. They then come up with a hypothesis, a testable explanation that addresses the question.
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Testing a(n) __________ involves performing a(n) __________.
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