hypothesis
Sociology
Writing
Biology
an educated guess that usually is found in an "if...then..." format
Economics
An assumption taken to be true for the purpose of argument or investigation.
Psychology
Examples of hypothesis in the following topics:

Student Learning Outcomes
 Conduct and interpret hypothesis tests for two population means, population standard deviations known.
 Conduct and interpret hypothesis tests for two population means, population standard deviations unknown.

The Null and the Alternative
 The alternative hypothesis and the null hypothesis are the two rival hypotheses that are compared by a statistical hypothesis test.
 In statistical hypothesis testing, the alternative hypothesis and the null hypothesis are the two rival hypotheses which are compared by a statistical hypothesis test.
 In the hypothesis testing approach of Jerzy Neyman and Egon Pearson, a null hypothesis is contrasted with an alternative hypothesis, and these are decided between on the basis of data, with certain error rates.
 The concept of an alternative hypothesis forms a major component in modern statistical hypothesis testing; however, it was not part of Ronald Fisher's formulation of statistical hypothesis testing.
 Modern statistical hypothesis testing accommodates this type of test, since the alternative hypothesis can be just the negation of the null hypothesis.

Does the Difference Prove the Point?
 Rejecting the null hypothesis does not necessarily prove the alternative hypothesis.
 The critical region of a hypothesis test is the set of all outcomes which cause the null hypothesis to be rejected in favor of the alternative hypothesis.
 Alternatively, if the testing procedure forces us to reject the null hypothesis ($H_0$), we can accept the alternative hypothesis ($H_1$) and we conclude that the research hypothesis is supported by the data.
 Rejection of the null hypothesis is a conclusion.
 We might accept the alternative hypothesis (and the research hypothesis).

Student Learning Outcomes
 Conduct and interpret hypothesis tests for a single population mean, population standard deviation known.
 Conduct and interpret hypothesis tests for a single population mean, population standard deviation unknown.

Student Learning Outcomes

Misconceptions
 State why the probability value is not the probability the null hypothesis is false
 Explain why a nonsignificant outcome does not mean the null hypothesis is probably true
 Misconception: The probability value is the probability that the null hypothesis is false.
 It is the probability of the data given the null hypothesis.
 It is not the probability that the null hypothesis is false.

Steps in Hypothesis Testing
 Be able to state the null hypothesis for both onetailed and twotailed tests
 The first step is to specify the null hypothesis.
 A typical null hypothesis is μ1  μ2 = 0 which is equivalent to μ1 = μ2.
 If the probability value is lower then you reject the null hypothesis.
 Failure to reject the null hypothesis does not constitute support for the null hypothesis.

Formulating the Hypothesis
 A hypothesis is a potential answer to your research question; the research process helps you determine if your hypothesis is true.
 This is an example of a causal hypothesis.
 To test this hypothesis, he compared twenty different regional Italian governments.
 To test this hypothesis, he compared twenty different regional Italian governments.
 While there is no single way to develop a hypothesis, a useful hypothesis will use deductive reasoning to make predictions that can be experimentally assessed.

Type I and II Errors
 Explain why the null hypothesis should not be accepted when the effect is not significant
 Instead, α is the probability of a Type I error given that the null hypothesis is true.
 If the null hypothesis is false, then it is impossible to make a Type I error.
 Lack of significance does not support the conclusion that the null hypothesis is true.
 A Type II error can only occur if the null hypothesis is false.

Elements of a Hypothesis Test
 The null hypothesis was that the Lady had no such ability.
 Fisher asserted that no alternative hypothesis was (ever) required.
 Statistical hypothesis tests define a procedure that controls (fixes) the probability of incorrectly deciding that a default position (null hypothesis) is incorrect based on how likely it would be for a set of observations to occur if the null hypothesis were true.
 The typical line of reasoning in a hypothesis test is as follows:
 There is an initial research hypothesis of which the truth is unknown.