Date of publication: 2017-09-02 22:27
If, for example, a person wants to test that a penny has exactly a 55% chance of landing heads, the null hypothesis would be yes, and the null hypothesis would be no, it does not. Mathematically, the null hypothesis would be represented as Ho: P = . The alternative hypothesis would be denoted as "Ha" and be identical to the null hypothesis, except with the equal sign struck-through, meaning that it does not equal 55%.
Taking the same example, a researcher might expect that the economic class and educational attainment of one s parents, and the race of the person in question are likely to have an effect on one s educational attainment.
During a test, the scientist may try to prove or disprove just the null hypothesis or test both the null and the alternative hypothesis. If a hypothesis specifies a certain direction, it is called one-tailed hypothesis. This means that the scientist believes that the outcome will be either with effect or without effect. When a hypothesis is created with no prediction to the outcome, it is called a two-tailed hypothesis because there are two possible outcomes. The outcome could be with effect or without effect, but until the testing is complete, there is no way of knowing which outcome it will be, according to the Web Center for Social Research Methods.
A null hypothesis is a type of hypothesis used in statistics that proposes that no statistical significance exists in a set of given observations. The null hypothesis attempts to show that no variation exists between variables or that a single variable is no different than its mean. It is presumed to be true until statistical evidence nullifies it for an alternative hypothesis. BREAKING DOWN 'Null Hypothesis' The null hypothesis, also known as the conjecture, assumes that any kind of difference or significance you see in a set of data is due to chance. The opposite of the null hypothesis is known as the alternative hypothesis.
Students sometimes confuse the idea of falsifiability with the idea that it means that something is false, which is not the case. What falsifiability means is that if something was false, then it is possible to demonstrate that it is false.
A null hypothesis is the name given to a hypothesis that is possibly false or has no effect. Often, during a test, the scientist will study another branch of the idea that may work, which is called an alternative hypothesis, according to the University of California, Berkeley.
A scientific theory summarizes a hypothesis or group of hypotheses that have been supported with repeated testing. A theory is valid as long as there is no evidence to dispute it. Therefore, theories can be disproven. Basically, if evidence accumulates to support a hypothesis, then the hypothesis can become accepted as a good explanation of a phenomenon. One definition of a theory is to say it s an accepted hypothesis.
Imagine you have a test at school tomorrow. You stay out late and see a movie with friends. You know that when you study the night before, you get good grades. What do you think will happen on tomorrow's test?
Upon analysis of the results, a hypothesis can be rejected or modified, but it can never be proven to be correct 655 percent of the time. For example, relativity has been tested many times, so it is generally accepted as true, but there could be an instance, which has not been encountered, where it is not true. For example, a scientist can form a hypothesis that a certain type of tomato is red. During research, the scientist then finds that each tomato of this type is red. Though his findings confirm his hypothesis, there may be a tomato of that type somewhere in the world that isn t red. Thus, his hypothesis is true, but it may not be true 655 percent of the time.