hypotheses

Examples of hypotheses in the following topics:

• Optional Collaborative Classroom Activity

  • In groups, find articles from which your group can write a null and alternate hypotheses.
  • Discuss your hypotheses with the rest of the class.

• The Scientific Method

  • Hypotheses often also include an explanation for the educated guess.
  • To solve one problem, several hypotheses may be proposed.
  • Generally, hypotheses have the format "If...then..."
  • Using the scientific method, the hypotheses that are inconsistent with experimental data are rejected.
  • Discuss hypotheses and the components of a scientific experiment as part of the scientific method

• Hypotheses about the means of multiple groups

  • The procedure Tools>Testing Hypotheses>Node-level>Anova provides the regular OLS approach to estimating differences in group means.
  • The dialog for Tools>Testing Hypotheses>Node-level>Anova looks very much like Tools>Testing Hypotheses>Node-level>T-test, so we won't display it.

• Milton Friedman

  • The body of "substantive hypotheses" or theory is primarily to yield "valid and meaningful (i.e. not truistic) predictions about phenomena not yet observed" (Ibid).
  • The only test of the validity of the hypotheses or theory is its "predictive power for the class of phenomena it is intended to ‘explain. ' If there are alternative hypotheses that may be chosen, Friedman suggests two criteria; simplicity and fruitfulness.
  • A more "fruitful" set of hypotheses would also suggest additional lines of research.
  • "hypothesis can be tested only by the conformity of its implications or predictions with observable phenomena; but it does render the task of testing hypotheses more difficult and gives greater scope for confusion about the methodological principles involved.

• Scientific Method - The Practice of Science

  • Scientists use the scientific method—a standardized protocol for observing, asking questions about and investigating natural phenomena—to test hypotheses.
  • Good hypotheses are testable—turn them into if/then (predictive) statements or yes-or-no questions.
  • Integrate your experimental results with earlier hypotheses and prior knowledge.
  • In the last analysis, think of hypotheses as educated guesses and think of Theories and/or Laws as one or more experimentally supported hypothesis that everyone agrees should serve as guideposts to help us evaluate new observations and hypotheses.
  • The cycle of formulating hypotheses, testing and analyzing the results, and formulating new hypotheses, will resemble the cycle described below:

• Can occur individually or in a social group

  • Conceptualization/Hypothesizing: Further processing of the experience; creating concepts to explain the experience and construction of explanatory hypotheses.
  • Addressing: The concepts and hypotheses that have been constructed are formulated and the experience is addressed in some manner.There is an attempt to predict future experience.This may involve planning, active experimentation, or cautious testing.

• Multivariate Testing

  • Hotelling's $T$-square statistic allows for the testing of hypotheses on multiple (often correlated) measures within the same sample.
  • A generalization of Student's $t$-statistic, called Hotelling's $T$-square statistic, allows for the testing of hypotheses on multiple (often correlated) measures within the same sample.
  • Because measures of this type are usually highly correlated, it is not advisable to conduct separate univariate $t$-tests to test hypotheses, as these would neglect the covariance among measures and inflate the chance of falsely rejecting at least one hypothesis (type I error).

• The Null and Alternate Hypotheses

• 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.
  • Such hypotheses are usually of no practical interest but are fundamental to theoretical considerations of statistical inference.
  • A hypothesis test begins by consider the null and alternate hypotheses, each containing an opposing viewpoint.
  • Differentiate between the null and alternative hypotheses and understand their implications in hypothesis testing.

• Null and Alternate Hypotheses

  • The actual test begins by considering two hypotheses.
  • These hypotheses contain opposing viewpoints.
  • Since the null and alternate hypotheses are contradictory, you must examine evidence to decide if you have enough evidence to reject the null hypothesis or not.